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Robinson N, Ploner A, Leone M, Lichtenstein P, Kendler KS, Bergen SE. Environmental risk factors for schizophrenia and bipolar disorder from childhood to diagnosis: a Swedish nested case-control study. Psychol Med 2024; 54:2162-2171. [PMID: 38425272 PMCID: PMC11366041 DOI: 10.1017/s0033291724000266] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 03/02/2024]
Abstract
BACKGROUND Shared genetic risk between schizophrenia (SCZ) and bipolar disorder (BD) is well-established, yet the extent to which they share environmental risk factors remains unclear. We compare the associations between environmental exposures during childhood/prior to disorder onset with the risk of developing SCZ and BD. METHODS We conducted a Swedish register-based nested case-control study using 4184 SCZ cases and 18 681 BD cases diagnosed 1988-2013. Cases were matched to five controls by birth year, birth region, and sex. Conditional logistic regression was used to estimate incidence rate ratios (IRR) for SCZ and BD for each exposure (severe childhood infections, adverse childhood experiences (ACEs), substance use disorders (SUDs), urban birth/longest residence). RESULTS All SUD types were associated with very high risk (IRR 4.9-25.5), and all forms of ACEs with higher risk (IRR 1.5-4.3) for both disorders. In the mutually adjusted models, ACEs demonstrated slightly higher risk for BD (SCZ IRR 1.30, 1.19-1.42; BD IRR 1.49, 1.44-1.55), while for SUD, risk was higher for SCZ (SCZ IRR 9.43, 8.15-10.92; BD IRR 5.50, 5.15-5.88). Infections were associated with increased risk of BD (IRR 1.21, 1.17-1.26) but not SCZ. Urban birth and urban longest residence were associated with higher risk of SCZ (IRR 1.19, 1.03-1.37), while only the combination of urban birth and rural longest residence showed higher risk for BD (IRR 1.24, 1.13-1.35). CONCLUSIONS There were both shared and unique environmental risk factors: SUDs and ACEs were risk factors for both disorders, while infections were more strongly associated with BD and urbanicity with SCZ.
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Affiliation(s)
- Natassia Robinson
- Department of Medical Epidemiology and Biostatistics, Karolinska Institutet, Stockholm, Sweden
| | - Alexander Ploner
- Department of Medical Epidemiology and Biostatistics, Karolinska Institutet, Stockholm, Sweden
| | - Marica Leone
- Department of Medical Epidemiology and Biostatistics, Karolinska Institutet, Stockholm, Sweden
- Janssen Pharmaceutical Companies of Johnson & Johnson, Solna, Sweden
| | - Paul Lichtenstein
- Department of Medical Epidemiology and Biostatistics, Karolinska Institutet, Stockholm, Sweden
| | - Kenneth S. Kendler
- Department of Psychiatry, Virginia Institute for Psychiatric and Behavioral Genetics, Virginia Commonwealth University, Richmond, VA, USA
| | - Sarah E. Bergen
- Department of Medical Epidemiology and Biostatistics, Karolinska Institutet, Stockholm, Sweden
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Fekih-Romdhane F, Alhuwailah A, Shuwiekh HAM, Stambouli M, Hakiri A, Cheour M, Loch AA, Hallit S. Development and initial validation of the cannabis-related psychosis risk literacy scale (CPRL): a multinational psychometric study. BMC Psychiatry 2024; 24:298. [PMID: 38641784 PMCID: PMC11027227 DOI: 10.1186/s12888-024-05727-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/01/2023] [Accepted: 03/27/2024] [Indexed: 04/21/2024] Open
Abstract
BACKGROUND Public education efforts to address and reduce potential harms from cannabis use in Arab countries are either slow or inexistent, and do not follow the steadily increasing trends of cannabis use in Arab youth. Several decades of research on substance use, it can be suggested that being aware of, and knowing about, psychosis risk related to cannabis can at least limit the consumption of the substance. Motivated by a lack of measures specifically designed to measure literacy about cannabis-related psychosis risk in younger populations, and based on an extensive literature review, we aimed to create and validate a new self-report scale to assess the construct, the Cannabis-related Psychosis Risk Literacy Scale (CPRL), in the Arabic language. METHOD A cross-sectional study was carried-out during the period from September 2022 to June 2023, enrolling 1855 university students (mean age of 23.26 ± 4.96, 75.6% females) from three Arab countries (Egypt, Kuwait and Tunisia). RESULTS Starting from an initial pool of 20 items, both Exploratory Factor Analysis and Confirmatory Factor Analysis suggested that the remaining 8 items loaded into a single factor. The scale demonstrated good internal consistency, with both McDonald omega and Cronbach's alpha values exceeding 0.7 (omega = 0.85 / alpha = 0.85). The CPRL showed measurement invariance across gender and country at the configural, metric, and scalar levels. Concurrent validity of the CPRL was established by correlations with less favourable attitudes towards cannabis (r = -.14; p <.001). In addition, higher literacy levels were found in students who never used cannabis compared to lifetime users (4.18 ± 1.55 vs. 3.44 ± 1.20, t(1853) = 8.152, p <.001). CONCLUSION The newly developed CPRL scale offers a valid and reliable instrument for assessing and better understanding literacy about cannabis-related psychosis risk among Arabic-speaking young adults. We believe that this new scale is suitable as a screening tool of literacy, as an instrument for measuring the effect of public education interventions aimed at promoting cannabis-related psychosis risk literacy among young people, and as a research tool to facilitate future studies on the topic with a wider application.
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Affiliation(s)
- Feten Fekih-Romdhane
- Faculty of Medicine of Tunis, Tunis Al Manar University, Tunis, Tunisia.
- The Tunisian Center of Early Intervention in Psychosis, Department of Psychiatry Ibn Omrane, Razi Hospital, Tunis, Tunisia.
| | | | | | - Manel Stambouli
- Faculty of Medicine of Tunis, Tunis Al Manar University, Tunis, Tunisia
| | - Abir Hakiri
- Faculty of Medicine of Tunis, Tunis Al Manar University, Tunis, Tunisia
| | - Majda Cheour
- Faculty of Medicine of Tunis, Tunis Al Manar University, Tunis, Tunisia
- The Tunisian Center of Early Intervention in Psychosis, Department of Psychiatry Ibn Omrane, Razi Hospital, Tunis, Tunisia
| | - Alexandre Andrade Loch
- Laboratorio de Neurociencias (LIM 27), Instituto de Psiquiatria, Hospital das Clinicas HCFMUSP, Faculdade de Medicina, Universidade de Sao Paulo, Sao Paulo, SP, BR, Brazil
- Instituto Nacional de Biomarcadores em Neuropsiquiatria (INBION), Conselho Nacional de Desenvolvimento Cientifico e Tecnológico, Sao Paulo, Brazil
| | - Souheil Hallit
- Psychology Department, College of Humanities, Effat University, 21478, Jeddah, Saudi Arabia.
- Applied Science Research Center, Applied Science Private University, Amman, Jordan.
- School of Medicine and Medical Sciences, Souheil Hallit, Holy Spirit University of Kaslik, Jounieh, P.O. Box 446, Lebanon.
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3
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Kapler S, Adery L, Hoftman GD, Amir CM, Grigoryan V, Cooper ZD, Bearden CE. Assessing evidence supporting cannabis harm reduction practices for adolescents at clinical high-risk for psychosis: a review and clinical implementation tool. Psychol Med 2024; 54:245-255. [PMID: 37882050 DOI: 10.1017/s0033291723002994] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/27/2023]
Abstract
Cannabis use is consistently associated with both increased incidence of frank psychotic disorders and acute exacerbations of psychotic symptoms in healthy individuals and people with psychosis spectrum disorders. Although there is uncertainty around causality, cannabis use may be one of a few modifiable risk factors for conversion to psychotic disorders in individuals with Clinical High Risk for Psychosis (CHR-P) syndromes, characterized by functionally impairing and distressing subthreshold psychotic symptoms. To date, few recommendations beyond abstinence to reduce adverse psychiatric events associated with cannabis use have been made. This narrative review synthesizes existing scientific literature on cannabis' acute psychotomimetic effects and epidemiological associations with psychotic disorders in both CHR-P and healthy individuals to bridge the gap between scientific knowledge and practical mental health intervention. There is compelling evidence for cannabis acutely exacerbating psychotic symptoms in CHR-P, but its impact on conversion to psychotic disorder is unclear. Current evidence supports a harm reduction approach in reducing frequency of acute psychotic-like experiences, though whether such interventions decrease CHR-P individuals' risk of conversion to psychotic disorder remains unknown. Specific recommendations include reducing frequency of use, lowering delta-9-tetrahydrocannabinol content in favor of cannabidiol-only products, avoiding products with inconsistent potency like edibles, enhancing patient-provider communication about cannabis use and psychotic-like experiences, and utilizing a collaborative and individualized therapeutic approach. Despite uncertainty surrounding cannabis' causal association with psychotic disorders, cautious attempts to reduce acute psychosis risk may benefit CHR-P individuals uninterested in abstinence. Further research is needed to clarify practices associated with minimization of cannabis-related psychosis risk.
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Affiliation(s)
- Simon Kapler
- Semel Institute for Neuroscience and Human Behavior, Departments of Psychiatry and Behavioral Sciences, University of California, Los Angeles, CA, USA
| | - Laura Adery
- Semel Institute for Neuroscience and Human Behavior, Departments of Psychiatry and Behavioral Sciences, University of California, Los Angeles, CA, USA
| | - Gil D Hoftman
- Semel Institute for Neuroscience and Human Behavior, Departments of Psychiatry and Behavioral Sciences, University of California, Los Angeles, CA, USA
| | - Carolyn M Amir
- Semel Institute for Neuroscience and Human Behavior, Departments of Psychiatry and Behavioral Sciences, University of California, Los Angeles, CA, USA
- Neuroscience Interdepartmental Program, University of California, Los Angeles, CA, USA
| | - Vardui Grigoryan
- Semel Institute for Neuroscience and Human Behavior, Departments of Psychiatry and Behavioral Sciences, University of California, Los Angeles, CA, USA
| | - Ziva D Cooper
- Semel Institute for Neuroscience and Human Behavior, Departments of Psychiatry and Behavioral Sciences, University of California, Los Angeles, CA, USA
- UCLA Center for Cannabis and Cannabinoids, University of California, Los Angeles, CA, USA
| | - Carrie E Bearden
- Semel Institute for Neuroscience and Human Behavior, Departments of Psychiatry and Behavioral Sciences, University of California, Los Angeles, CA, USA
- Department of Psychology, University of California, Los Angeles, CA, USA
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4
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Zhang X, Huangfu Z, Wang S. Review of mendelian randomization studies on age at natural menopause. Front Endocrinol (Lausanne) 2023; 14:1234324. [PMID: 37766689 PMCID: PMC10520463 DOI: 10.3389/fendo.2023.1234324] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/04/2023] [Accepted: 08/18/2023] [Indexed: 09/29/2023] Open
Abstract
Menopause marks the end of the reproductive phase of life. Based on epidemiological studies, abnormal age at natural menopause (ANM) is thought to contribute to a number of adverse outcomes, such as osteoporosis, cardiovascular disease, and cancer. However, the causality of these associations remains unclear. A powerful epidemiological method known as Mendelian randomization (MR) can be used to clarify the causality between ANM and other diseases or traits. The present review describes MR studies that included ANM as an exposure, outcome and mediator. The findings of MR analyses on ANM have revealed that higher body mass index, poor educational level, early age at menarche, early age at first live birth, early age at first sexual intercourse, and autoimmune thyroid disease appear to be involved in early ANM etiology. The etiology of late ANM appears to be influenced by higher free thyroxine 4 and methylene tetrahydrofolate reductase gene mutations. Furthermore, early ANM has been found to be causally associated with an increased risk of osteoporosis, fracture, type 2 diabetes mellitus, glycosylated hemoglobin, and the homeostasis model of insulin resistance level. In addition, late ANM has been found to be causally associated with an increased systolic blood pressure, higher risk of breast cancer, endometrial cancer, endometrioid ovarian carcinoma, lung cancer, longevity, airflow obstruction, and lower risk of Parkinson's disease. ANM is also a mediator for breast cancer caused by birth weight and childhood body size. However, due to the different instrumental variables used, some results of studies are inconsistent. Future studies with more valid genetic variants are needed for traits with discrepancies between MRs or between MR and other types of epidemiological studies.
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Affiliation(s)
- Xiao Zhang
- Department of Obstetrics and Gynecology, Beijing Hospital, National Center of Gerontology, Beijing, China
- Institute of Geriatric Medicine, Chinese Academy of Medical Science, Beijing, China
- Graduate School of Peking Union Medical College, Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing, China
| | - Zhao Huangfu
- Department of Urology, Changhai Hospital, Naval Medical University, Shanghai, China
| | - Shaowei Wang
- Department of Obstetrics and Gynecology, Beijing Hospital, National Center of Gerontology, Beijing, China
- Institute of Geriatric Medicine, Chinese Academy of Medical Science, Beijing, China
- Graduate School of Peking Union Medical College, Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing, China
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5
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Elkrief L, Lin B, Marchi M, Afzali MH, Banaschewski T, Bokde ALW, Quinlan EB, Desrivières S, Flor H, Garavan H, Gowland P, Heinz A, Ittermann B, Martinot JL, Martinot MLP, Nees F, Orfanos DP, Paus T, Poustka L, Hohmann S, Fröhner JH, Smolka MN, Walter H, Whelan R, Schumann G, Luykx J, Boks MP, Conrod PJ. Independent contribution of polygenic risk for schizophrenia and cannabis use in predicting psychotic-like experiences in young adulthood: testing gene × environment moderation and mediation. Psychol Med 2023; 53:1759-1769. [PMID: 37310336 PMCID: PMC10106286 DOI: 10.1017/s0033291721003378] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/29/2021] [Revised: 07/20/2021] [Accepted: 07/26/2021] [Indexed: 12/16/2022]
Abstract
BACKGROUND It has not yet been determined if the commonly reported cannabis-psychosis association is limited to individuals with pre-existing genetic risk for psychotic disorders. METHODS We examined whether the relationship between polygenic risk score for schizophrenia (PRS-Sz) and psychotic-like experiences (PLEs), as measured by the Community Assessment of Psychic Experiences-42 (CAPE-42) questionnaire, is mediated or moderated by lifetime cannabis use at 16 years of age in 1740 of the individuals of the European IMAGEN cohort. Secondary analysis examined the relationships between lifetime cannabis use, PRS-Sz and the various sub-scales of the CAPE-42. Sensitivity analyses including covariates, including a PRS for cannabis use, were conducted and results were replicated using data from 1223 individuals in the Dutch Utrecht cannabis cohort. RESULTS PRS-Sz significantly predicted cannabis use (p = 0.027) and PLE (p = 0.004) in the IMAGEN cohort. In the full model, considering PRS-Sz and covariates, cannabis use was also significantly associated with PLE in IMAGEN (p = 0.007). Results remained consistent in the Utrecht cohort and through sensitivity analyses. Nevertheless, there was no evidence of a mediation or moderation effects. CONCLUSIONS These results suggest that cannabis use remains a risk factor for PLEs, over and above genetic vulnerability for schizophrenia. This research does not support the notion that the cannabis-psychosis link is limited to individuals who are genetically predisposed to psychosis and suggests a need for research focusing on cannabis-related processes in psychosis that cannot be explained by genetic vulnerability.
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Affiliation(s)
- Laurent Elkrief
- Sainte-Justine Hospital Research Center, Montréal, Québec, Canada
- Département de psychiatrie et d'addictologie, Université de Montréal, Montréal, QC, Canada
| | - Bochao Lin
- Department of Translational Neuroscience, Brain Center University Medical Center, Utrecht University, Utrecht, the Netherlands
| | - Mattia Marchi
- Department Psychiatry, Brain Center University Medical Center Utrecht, Utrecht, the Netherlands
- Department of Biomedical, Metabolic and Neural Sciences, University of Modena and Reggio Emilia, Via Giuseppe Campi, 287–41125 Modena, Italy
| | - Mohammad H Afzali
- Sainte-Justine Hospital Research Center, Montréal, Québec, Canada
- Département de psychiatrie et d'addictologie, Université de Montréal, Montréal, QC, Canada
| | - Tobias Banaschewski
- Department of Child and Adolescent Psychiatry and Psychotherapy, Central Institute of Mental Health, Medical Faculty Mannheim, Heidelberg University, Square J5, 68159 Mannheim, Germany
| | - Arun L. W. Bokde
- Discipline of Psychiatry, School of Medicine and Trinity College Institute of Neuroscience, Trinity College Dublin, Dublin 2, Ireland
| | - Erin Burke Quinlan
- Centre for Population Neuroscience and Precision Medicine (PONS), Institute of Psychiatry, Psychology & Neuroscience, SGDP Centre, King's College London, United Kingdom
| | - Sylvane Desrivières
- Centre for Population Neuroscience and Precision Medicine (PONS), Institute of Psychiatry, Psychology & Neuroscience, SGDP Centre, King's College London, United Kingdom
| | - Herta Flor
- Department of Cognitive and Clinical Neuroscience, Central Institute of Mental Health, Medical Faculty Mannheim, Heidelberg University, Square J5, Mannheim, Germany
- Department of Psychology, School of Social Sciences, University of Mannheim, 68131 Mannheim, Germany
| | - Hugh Garavan
- Departments of Psychiatry and Psychology, University of Vermont, 05405 Burlington, Vermont, USA
| | - Penny Gowland
- Sir Peter Mansfield Imaging Centre School of Physics and Astronomy, University of Nottingham, University Park, Nottingham, United Kingdom
| | - Andreas Heinz
- Charité – Universitätsmedizin Berlin, Department of Psychiatry and Psychotherapy, Campus Charité Mitte, Charitéplatz 1, Berlin, Germany
| | - Bernd Ittermann
- Physikalisch-Technische Bundesanstalt (PTB), Abbestr. 2 - 12, Berlin, Germany
| | - Jean-Luc Martinot
- Institut National de la Santé et de la Recherche Médicale, INSERM Unit 1000 “Neuroimaging & Psychiatry”, University Paris Saclay, University Paris Descartes - Sorbonne Paris Cité; and Maison de Solenn, Paris, France
| | - Marie-Laure Paillère Martinot
- Institut National de la Santé et de la Recherche Médicale, INSERM Unit 1000 “Neuroimaging & Psychiatry”, University Paris Sud, University Paris Descartes; and AP-HP.Sorbonne Université, Department of Child and Adolescent Psychiatry, Pitié-Salpêtrière Hospital, Paris, France
| | - Frauke Nees
- Department of Child and Adolescent Psychiatry and Psychotherapy, Central Institute of Mental Health, Medical Faculty Mannheim, Heidelberg University, Square J5, 68159 Mannheim, Germany
- Department of Cognitive and Clinical Neuroscience, Central Institute of Mental Health, Medical Faculty Mannheim, Heidelberg University, Square J5, Mannheim, Germany
| | | | - Tomáš Paus
- Bloorview Research Institute, Holland Bloorview Kids Rehabilitation Hospital, Toronto, Ontario, Canada
| | - Luise Poustka
- Department of Child and Adolescent Psychiatry and Psychotherapy, University Medical Centre Göttingen, von-Siebold-Str. 5, 37075, Göttingen, Germany
| | - Sarah Hohmann
- Department of Child and Adolescent Psychiatry and Psychotherapy, Central Institute of Mental Health, Medical Faculty Mannheim, Heidelberg University, Square J5, 68159 Mannheim, Germany
| | - Juliane H. Fröhner
- Department of Psychiatry and Neuroimaging Center, Technische Universität Dresden, Dresden, Germany
| | - Michael N. Smolka
- Department of Psychiatry and Neuroimaging Center, Technische Universität Dresden, Dresden, Germany
| | - Henrik Walter
- Charité – Universitätsmedizin Berlin, Department of Psychiatry and Psychotherapy, Campus Charité Mitte, Charitéplatz 1, Berlin, Germany
| | - Robert Whelan
- School of Psychology and Global Brain Health Institute, Trinity College Dublin, Ireland
| | - Gunter Schumann
- Centre for Population Neuroscience and Precision Medicine (PONS), Institute of Psychiatry, Psychology & Neuroscience, SGDP Centre, King's College London, United Kingdom
- School of Psychology and Global Brain Health Institute, Trinity College Dublin, Ireland
- PONS Research Group, Dept of Psychiatry and Psychotherapy, Campus Charite Mitte, Humboldt University, Berlin and Leibniz Institute for Neurobiology, Magdeburg, Germany, and Institute for Science and Technology of Brain-inspired Intelligence (ISTBI), Fudan University, Shanghai, P.R. China
| | - Jurjen Luykx
- Department Psychiatry, Brain Center University Medical Center Utrecht, Utrecht, the Netherlands
| | - Marco P. Boks
- Department Psychiatry, Brain Center University Medical Center Utrecht, Utrecht, the Netherlands
| | - Patricia J. Conrod
- Sainte-Justine Hospital Research Center, Montréal, Québec, Canada
- Département de psychiatrie et d'addictologie, Université de Montréal, Montréal, QC, Canada
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Abstract
Cannabis is one of the most widely used recreational drugs among people with clinical psychosis, after nicotine and alcohol. There has been a debate in psychiatry about whether or not we can infer a cause-and-effect relationship between the use of cannabis and psychotic disorders. In this editorial, we first present and critically discuss the evidence to date of the association between heavy cannabis use and psychosis. We argue that while the biological mechanisms underlying individual susceptibility to develop a psychotic disorder following heavy cannabis use are still unknown, heavy cannabis use remains the most modifiable risk factor for the onset of psychotic disorders and for its clinical and functional outcome. This demands a clear move towards both primary and secondary prevention intervention to reduce the impact of heavy cannabis use on the incidence and prevalence of psychotic disorders.
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Affiliation(s)
- L Johnson-Ferguson
- Jacobs Center for Productive Youth Development, University of Zurich, Zurich, Switzerland
- Psychiatric University Hospital, Zurich, Switzerland
- Department of Psychosis Studies, Institute of Psychiatry, King's College London, London, UK
| | - M Di Forti
- Social, Genetic and Developmental Psychiatry Centre, Institute of Psychiatry, King's College London, London, UK
- South London and Maudsley NHS Mental Health Foundation Trust, London, UK
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7
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Wang GS, Buttorff C, Wilks A, Schwam D, Tung G, Pacula RL. Impact of cannabis legalization on healthcare utilization for psychosis and schizophrenia in Colorado. THE INTERNATIONAL JOURNAL OF DRUG POLICY 2022; 104:103685. [PMID: 35429874 DOI: 10.1016/j.drugpo.2022.103685] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2021] [Revised: 03/18/2022] [Accepted: 04/02/2022] [Indexed: 10/18/2022]
Abstract
BACKGROUND Emergency department (ED) visits involving psychosis and schizophrenia have increased at a rate exceeding population growth in the United States over the past decade. Research shows a strong dose-response relationship between chronic use of high-potency cannabis and odds of developing symptoms of psychosis. The aim of this study was to evaluate the impact of cannabis legalization on psychosis and schizophrenia-related ED visits in Colorado. METHODS Using administrative data from Colorado Hospital Association (CHA) on county-level quarterly ED visits between January 1, 2013, and December 31, 2018, we applied a difference-in-difference analysis to examine how new exposure to recreational cannabis dispensaries after 2014 differentially influenced the rate of ED visits for psychosis and schizophrenia, comparing counties with no prior medical cannabis dispensary exposure to counties with low or high medical dispensary exposure. RESULTS As recreational dispensaries per 10,000 residents increased, there was no significant association with the rate of schizophrenia ED visits per capita (incidence rate ratio or IRR: 0.95, 95% CI [0.69, 1.30]) while the rate of psychosis visits increased 24% (IRR: 1.24, 95% CI [1.02, 1.49]). Counties with no previous medical dispensaries experienced larger increases in schizophrenia ED visits than counties already exposed to a low level of medical dispensaries, but this effect was not significant. Counties with low baseline medical exposure had lower increases in rates of psychosis visits than counties with high baseline medical exposure (IRR 0.83, 95% CI [0.69, 0.99]). CONCLUSIONS There was a positive association between the number of cannabis dispensaries and rates of psychosis ED visits across all counties in Colorado. Although it is unclear whether it is access to products, or the types of products that may be driving this association, our findings suggest there is a potential impact on the mental health of the local population that is observed after cannabis legalization.
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Affiliation(s)
- George Sam Wang
- University of Colorado Anschutz Medical Campus Children's, Hospital Colorado Department of Pediatrics 13123 East 16th Ave B251 Aurora CO 80045, United States.
| | | | - Asa Wilks
- RAND Corporation, 1776 Main Street Santa Monica, CA 90407, United States.
| | - Daniel Schwam
- RAND Corporation, 1200 S. Hayes St Arlington VA 22202, United States.
| | - Gregory Tung
- University of Colorado Anschutz Medical Campus Colorado School of Public Health Department of Health Systems, Management & Policy Program for Injury Prevention, Education and Research (PIPER) Colorado School of Public Health, 13001 E. 17th Place, MS B119, United States.
| | - Rosalie Liccardo Pacula
- University of Southern California Sol Price School of Public Policy, Schaeffer Center for Health Policy & Economics 635 Downey Way, VPD 514J, Los Angeles, CA 90089-3333, United States.
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8
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Miller CL. The Epigenetics of Psychosis: A Structured Review with Representative Loci. Biomedicines 2022; 10:561. [PMID: 35327363 PMCID: PMC8945330 DOI: 10.3390/biomedicines10030561] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2022] [Revised: 02/24/2022] [Accepted: 02/26/2022] [Indexed: 02/04/2023] Open
Abstract
The evidence for an environmental component in chronic psychotic disorders is strong and research on the epigenetic manifestations of these environmental impacts has commenced in earnest. In reviewing this research, the focus is on three genes as models for differential methylation, MCHR1, AKT1 and TDO2, each of which have been investigated for genetic association with psychotic disorders. Environmental factors associated with psychotic disorders, and which interact with these model genes, are explored in depth. The location of transcription factor motifs relative to key methylation sites is evaluated for predicted gene expression results, and for other sites, evidence is presented for methylation directing alternative splicing. Experimental results from key studies show differential methylation: for MCHR1, in psychosis cases versus controls; for AKT1, as a pre-existing methylation pattern influencing brain activation following acute administration of a psychosis-eliciting environmental stimulus; and for TDO2, in a pattern associated with a developmental factor of risk for psychosis, in all cases the predicted expression impact being highly dependent on location. Methylation induced by smoking, a confounding variable, exhibits an intriguing pattern for all three genes. Finally, how differential methylation meshes with Darwinian principles is examined, in particular as it relates to the "flexible stem" theory of evolution.
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9
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Robinson N, Bergen SE. Environmental Risk Factors for Schizophrenia and Bipolar Disorder and Their Relationship to Genetic Risk: Current Knowledge and Future Directions. Front Genet 2021; 12:686666. [PMID: 34262598 PMCID: PMC8273311 DOI: 10.3389/fgene.2021.686666] [Citation(s) in RCA: 54] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2021] [Accepted: 05/20/2021] [Indexed: 12/16/2022] Open
Abstract
Schizophrenia (SZ) and bipolar disorder (BD) are severe psychiatric disorders which result from complex interplay between genetic and environmental factors. It is well-established that they are highly heritable disorders, and considerable progress has been made identifying their shared and distinct genetic risk factors. However, the 15-40% of risk that is derived from environmental sources is less definitively known. Environmental factors that have been repeatedly investigated and often associated with SZ include: obstetric complications, infections, winter or spring birth, migration, urban living, childhood adversity, and cannabis use. There is evidence that childhood adversity and some types of infections are also associated with BD. Evidence for other risk factors in BD is weaker due to fewer studies and often smaller sample sizes. Relatively few environmental exposures have ever been examined for SZ or BD, and additional ones likely remain to be discovered. A complete picture of how genetic and environmental risk factors confer risk for these disorders requires an understanding of how they interact. Early gene-by-environment interaction studies for both SZ and BD often involved candidate genes and were underpowered. Larger samples with genome-wide data and polygenic risk scores now offer enhanced prospects to reveal genetic interactions with environmental exposures that contribute to risk for these disorders. Overall, although some environmental risk factors have been identified for SZ, few have been for BD, and the extent to which these account for the total risk from environmental sources remains unknown. For both disorders, interactions between genetic and environmental risk factors are also not well understood and merit further investigation. Questions remain regarding the mechanisms by which risk factors exert their effects, and the ways in which environmental factors differ by sex. Concurrent investigations of environmental and genetic risk factors in SZ and BD are needed as we work toward a more comprehensive understanding of the ways in which these disorders arise.
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Affiliation(s)
| | - Sarah E. Bergen
- Department of Medical Epidemiology and Biostatistics, Karolinska Institutet, Stockholm, Sweden
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10
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Gillespie NA, Kendler KS. Use of Genetically Informed Methods to Clarify the Nature of the Association Between Cannabis Use and Risk for Schizophrenia. JAMA Psychiatry 2021; 78:467-468. [PMID: 33146687 DOI: 10.1001/jamapsychiatry.2020.3564] [Citation(s) in RCA: 29] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
Affiliation(s)
- Nathan A Gillespie
- Virginia Institute for Psychiatric and Behavior Genetics, Department of Psychiatry, Virginia Commonwealth University, Richmond.,QIMR Berghofer Medical Research Institute, Herston, Queensland, Australia
| | - Kenneth S Kendler
- Virginia Institute for Psychiatric and Behavior Genetics, Department of Psychiatry, Virginia Commonwealth University, Richmond
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11
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Thapar A, Rice F. Family-Based Designs that Disentangle Inherited Factors from Pre- and Postnatal Environmental Exposures: In Vitro Fertilization, Discordant Sibling Pairs, Maternal versus Paternal Comparisons, and Adoption Designs. Cold Spring Harb Perspect Med 2021; 11:cshperspect.a038877. [PMID: 32152247 PMCID: PMC7919395 DOI: 10.1101/cshperspect.a038877] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Identifying environmental risk and protective exposures that have causal effects on health is an important scientific goal. Many environmental exposures are nonrandomly allocated and influenced by dispositional factors including inherited ones. We review family-based designs that can separate the influence of environmental exposures from inherited influences shared between parent and offspring. We focus on prenatal exposures. We highlight that the family-based designs that can separate the prenatal environment from inherited confounds are different to those that are able to pull apart later-life environmental exposures from inherited confounds. We provide a brief review of the literature on maternal smoking during pregnancy and offspring attention-deficit/hyperactivity disorder (ADHD) and conduct problems; these inconsistencies in the literature make a review useful and this illustrates that results of family-based genetically informed studies are inconsistent with a causal interpretation for this exposure and these two offspring outcomes.
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Affiliation(s)
- Anita Thapar
- Child and Adolescent Psychiatry Section, Division of Psychological Medicine and Clinical Neurosciences, MRC Centre for Neuropsychiatric Genetics and Genomics, Cardiff University School of Medicine, Cardiff CF24 4HQ, United Kingdom
| | - Frances Rice
- Child and Adolescent Psychiatry Section, Division of Psychological Medicine and Clinical Neurosciences, MRC Centre for Neuropsychiatric Genetics and Genomics, Cardiff University School of Medicine, Cardiff CF24 4HQ, United Kingdom
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12
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Δ-9-Tetrahydrocannabinol treatment during adolescence and alterations in the inhibitory networks of the adult prefrontal cortex in mice subjected to perinatal NMDA receptor antagonist injection and to postweaning social isolation. Transl Psychiatry 2020; 10:177. [PMID: 32488050 PMCID: PMC7266818 DOI: 10.1038/s41398-020-0853-3] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/11/2019] [Revised: 05/11/2020] [Accepted: 05/19/2020] [Indexed: 12/18/2022] Open
Abstract
The prefrontal cortex (PFC) continues its development during adolescence and alterations in its structure and function, particularly of inhibitory networks, have been detected in schizophrenic patients. Since cannabis use during adolescence is a risk factor for this disease, our main objective was to investigate whether THC administration during this period might exacerbate alterations in prefrontocortical inhibitory networks in mice subjected to a perinatal injection of MK801 and postweaning social isolation. This double-hit model (DHM) combines a neurodevelopmental manipulation and the exposure to an aversive experience during early life; previous work has shown that DHM mice have important alterations in the structure and connectivity of PFC interneurons. In the present study we found that DHM had reductions in prepulse inhibition of the startle reflex (PPI), GAD67 expression and cingulate 1 cortex volume. Interestingly, THC by itself induced increases in PPI and decreases in the dendritic complexity of somatostatin expressing interneurons. Both THC and DHM reduced the density of parvalbumin expressing cells surrounded by perineuronal nets and, when combined, they disrupted the ratio between the density of puncta expressing excitatory and inhibitory markers. Our results support previous work showing alterations in parameters involving interneurons in similar animal models and schizophrenic patients. THC treatment does not modify further these parameters, but changes some others related also to interneurons and their plasticity, in some cases in the opposite direction to those induced by the DHM, suggesting a protective effect.
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13
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Rognli EB, Bramness JG, von Soest T. Cannabis use in early adulthood is prospectively associated with prescriptions of antipsychotics, mood stabilizers, and antidepressants. Acta Psychiatr Scand 2020; 141:149-156. [PMID: 31560790 DOI: 10.1111/acps.13104] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/27/2019] [Revised: 09/23/2019] [Accepted: 09/24/2019] [Indexed: 12/12/2022]
Abstract
OBJECTIVE Cannabis is an acknowledged risk factor for some mental disorders, but for others the evidence is inconclusive. Prescribed medicinal drugs can be used as proxies for mental disorders. In this study, we investigate how use of cannabis is prospectively related to prescription of antipsychotics, mood stabilizers, antidepressants, and anxiolytics. METHODS Data on cannabis exposure and relevant confounders were obtained from 2,602 individuals in the longitudinal Young in Norway Study, providing survey data from four data collection waves between 1992 and 2006. Data were coupled with information about prescriptions for psychotropic drugs from the Norwegian Prescription Database between 2007 and 2015. RESULTS Past year cannabis use increased the risk of prescription of antipsychotics (OR = 5.56, 95 % CI 1.64 - 18.87), mood stabilizers (OR = 5.36, 95 % CI 1.99 - 14.44) and antidepressants (OR = 2.10, 95 % CI 1.36 - 3.25), after accounting for sociodemographic variables, conduct problems, additional drug use, mental distress, and prescriptions the year before cannabis use was measured. CONCLUSIONS In this study of young adults from the general population, past year cannabis use was associated with later prescriptions of antipsychotics, mood stabilizers, and antidepressants.
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Affiliation(s)
- Eline Borger Rognli
- Section for Clinical Addiction Research, Department on Substance Use Disorder Treatment, Oslo University Hospital, Oslo, Norway
| | - Jørgen Gustav Bramness
- Norwegian National Advisory Unit on Concurrent Substance Abuse and Mental Health Disorders, Innlandet Hospital Trust, Hamar, Norway.,Institute for Clinical Medicine, University of Tromsø - The Arctic University of Norway, Tromsø, Norway.,Norwegian Institute of Public Health, Oslo, Norway
| | - Tilmann von Soest
- Department of Psychology, PROMENTA Research Center, University of Oslo, Oslo, Norway.,Norwegian Social Research (NOVA), OsloMet - Oslo Metropolitan University, Norway
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14
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Wright A, Cather C, Gilman J, Evins AE. The Changing Legal Landscape of Cannabis Use and Its Role in Youth-onset Psychosis. Child Adolesc Psychiatr Clin N Am 2020; 29:145-156. [PMID: 31708043 DOI: 10.1016/j.chc.2019.08.016] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
The rapidly changing landscape of cannabis in terms of availability, potency, and routes of administration, as well as the decrease in risk perception and changing norms, have contributed to an increase in the popularity of cannabis. Cannabis use is associated with a poorer recovery from a psychotic disorder, increasing the risk of relapse, rehospitalization, and lower social functioning. Data are mixed regarding cannabis use as a component cause of psychosis in people at risk for psychotic disorder. Care providers, parents, and schools must educate youth and adolescents about the risks of cannabis use.
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Affiliation(s)
- Abigail Wright
- Massachusetts General Hospital, Center of Excellence in Psychosocial and Systemic Research, 151 Merrimac Street, 6th Floor, Boston, MA 02114, USA; Harvard Medical School, Boston, MA USA.
| | - Corinne Cather
- Massachusetts General Hospital, Center of Excellence in Psychosocial and Systemic Research, 151 Merrimac Street, 6th Floor, Boston, MA 02114, USA; Harvard Medical School, Boston, MA USA
| | - Jodie Gilman
- Harvard Medical School, Boston, MA USA; Massachusetts General Hospital, Center for Addiction Medicine, 101 Merrimac Street, Boston, MA 02114, USA
| | - Anne Eden Evins
- Harvard Medical School, Boston, MA USA; Massachusetts General Hospital, Center for Addiction Medicine, 101 Merrimac Street, Boston, MA 02114, USA
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15
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Kendler KS, Ohlsson H, Sundquist J, Sundquist K. Prediction of Onset of Substance-Induced Psychotic Disorder and Its Progression to Schizophrenia in a Swedish National Sample. Am J Psychiatry 2019; 176:711-719. [PMID: 31055966 PMCID: PMC6718312 DOI: 10.1176/appi.ajp.2019.18101217] [Citation(s) in RCA: 51] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
OBJECTIVE The objective of this study was to clarify the etiology of substance-induced psychotic disorder and its progression to schizophrenia in a Swedish national sample. METHODS Individuals with a registration of substance-induced psychotic disorder between 1997 and 2015 in national medical registries (N=7,606) were followed up for a mean of 84 months. Data from medical, criminal, and pharmacy registries on first-degree through third-degree relatives were used to calculate familial risk scores for nonaffective psychosis, drug abuse, and alcohol use disorder. RESULTS Individuals with substance-induced psychotic disorder had large elevations in standardized familial risk scores for drug abuse (+1.09, 95% CI=1.02, 1.15) and alcohol use disorder (+0.98, 95% CI=0.93, 1.03) and modest elevations for nonaffective psychosis (+0.35, 95% CI=0.30, 0.41). The cumulative risk for progression to schizophrenia was 11.3%; it was lowest for alcohol-induced and highest for cannabis-induced psychotic disorder, and it was predicted by early age at diagnosis of substance-induced psychotic disorder, male sex, and further registrations for episodes of drug abuse, alcohol use disorder, and substance-induced psychotic disorder. A risk prediction model found that 47% of individuals who converted to schizophrenia were in the upper 20% of risk. Familial risk scores for drug abuse and alcohol use disorder did not significantly discriminate those who converted to schizophrenia from those who did not, while familial risk score for nonaffective psychosis did (0.67, 95% CI=0.40, 0.95, versus 0.33, 95% CI=0.28, 0.39). Familial risk scores for nonaffective psychosis were indistinguishable between individuals with schizophrenia with and without prior substance-induced psychosis. Assignment of early retirement by the Swedish Social Insurance Agency strongly discriminated between individuals with substance-induced psychotic disorder with and without later schizophrenia. CONCLUSIONS Substance-induced psychotic disorder appears to result from substantial drug exposure in individuals at high familial risk for substance abuse and moderately elevated familial risk for psychosis. Familial risk for psychosis, but not substance abuse, predicts progression from substance-induced psychosis to schizophrenia. Schizophrenia following substance-induced psychosis is likely a drug-precipitated disorder in highly vulnerable individuals, not a syndrome predominantly caused by drug exposure.
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Affiliation(s)
- Kenneth S. Kendler
- Virginia Institute for Psychiatric and Behavioral Genetics, Virginia Commonwealth University, Richmond, VA, USA,Department of Psychiatry, Virginia Commonwealth University, Richmond VA, USA
| | - Henrik Ohlsson
- Center for Primary Health Care Research, Lund University, Malmö, Sweden
| | - Jan Sundquist
- Center for Primary Health Care Research, Lund University, Malmö, Sweden,Department of Family Medicine and Community Health, Department of Population Health Science and Policy, Icahn School of Medicine at Mount Sinai, New York, USA,Center for Community-based Healthcare Research and Education (CoHRE), Department of Functional Pathology, School of Medicine, Shimane University, Japan
| | - Kristina Sundquist
- Center for Primary Health Care Research, Lund University, Malmö, Sweden,Department of Family Medicine and Community Health, Department of Population Health Science and Policy, Icahn School of Medicine at Mount Sinai, New York, USA,Center for Community-based Healthcare Research and Education (CoHRE), Department of Functional Pathology, School of Medicine, Shimane University, Japan
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16
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Ni G, Amare AT, Zhou X, Mills N, Gratten J, Lee SH. The genetic relationship between female reproductive traits and six psychiatric disorders. Sci Rep 2019; 9:12041. [PMID: 31427629 PMCID: PMC6700195 DOI: 10.1038/s41598-019-48403-x] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2019] [Accepted: 07/31/2019] [Indexed: 12/31/2022] Open
Abstract
Female reproductive behaviours have important implications for evolutionary fitness and health of offspring. Here we used the second release of UK Biobank data (N = 220,685) to evaluate the association between five female reproductive traits and polygenic risk scores (PRS) projected from genome-wide association study summary statistics of six psychiatric disorders (N = 429,178). We found that the PRS of attention-deficit/hyperactivity disorder (ADHD) were strongly associated with age at first birth (AFB) (genetic correlation of -0.68 ± 0.03), age at first sexual intercourse (AFS) (-0.56 ± 0.03), number of live births (NLB) (0.36 ± 0.04) and age at menopause (-0.27 ± 0.04). There were also robustly significant associations between the PRS of eating disorder (ED) and AFB (0.35 ± 0.06), ED and AFS (0.19 ± 0.06), major depressive disorder (MDD) and AFB (-0.27 ± 0.07), MDD and AFS (-0.27 ± 0.03) and schizophrenia and AFS (-0.10 ± 0.03). These associations were mostly explained by pleiotropic effects and there was little evidence of causal relationships. Our findings can potentially help improve reproductive health in women, hence better child outcomes. Our findings also lend partial support to the evolutionary hypothesis that causal mutations underlying psychiatric disorders have positive effects on reproductive success.
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Affiliation(s)
- Guiyan Ni
- Institute for Molecular Bioscience, University of Queensland, Brisbane, Queensland, 4072, Australia
- Australian Centre for Precision Health, University of South Australia Cancer Research Institute, University of South Australia, Adelaide, SA, 5000, Australia
- School of Environmental and Rural Science, University of New England, Armidale, NSW, 2351, Australia
| | - Azmeraw T Amare
- South Australian Academic Health Science and Translation centre, South Australian Health and Medical Research Institute (SAHMRI), Adelaide, South Australia, Australia
- Discipline of Psychiatry, School of Medicine, University of Adelaide, Adelaide, SA, Australia
| | - Xuan Zhou
- Australian Centre for Precision Health, University of South Australia Cancer Research Institute, University of South Australia, Adelaide, SA, 5000, Australia
| | - Natalie Mills
- Discipline of Psychiatry, School of Medicine, University of Adelaide, Adelaide, SA, Australia
| | - Jacob Gratten
- Institute for Molecular Bioscience, University of Queensland, Brisbane, Queensland, 4072, Australia
- Mater Research Institute, University of Queensland, Brisbane, Queensland, 4072, Australia
| | - S Hong Lee
- Australian Centre for Precision Health, University of South Australia Cancer Research Institute, University of South Australia, Adelaide, SA, 5000, Australia.
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17
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Gillespie NA, Pasman JA, Treur JL, Derks EM, Verweij KJH, Vink JM. High-potency cannabis and incident psychosis: correcting the causal assumption. Lancet Psychiatry 2019; 6:464. [PMID: 31122472 DOI: 10.1016/s2215-0366(19)30174-9] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/29/2019] [Revised: 04/04/2019] [Accepted: 04/05/2019] [Indexed: 10/26/2022]
Affiliation(s)
- Nathan A Gillespie
- Genetic Epidemiology, Statistical Genetics, and Translational Neurogenomics Laboratories, QIMR Berghofer Medical Research Institute, Brisbane, QLD, Australia; Department of Psychiatry, Virginia Institute for Psychiatric and Behavior Genetics, Virginia Commonwealth University, Richmond, VA, USA.
| | - Joelle A Pasman
- Behavioural Science Institute, Radboud University, Nijmegen, the Netherlands
| | - Jorien L Treur
- Department of Psychiatry, Amsterdam University Medical Center, University of Amsterdam, Amsterdam, the Netherlands
| | - Eske M Derks
- Translational Neurogenomics, QIMR Berghofer Medical Research Institute, Brisbane, QLD, Australia
| | - Karin J H Verweij
- Department of Psychiatry, Amsterdam University Medical Center, University of Amsterdam, Amsterdam, the Netherlands
| | - Jacqueline M Vink
- Behavioural Science Institute, Radboud University, Nijmegen, the Netherlands
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18
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Thapar A, Rutter M. Do natural experiments have an important future in the study of mental disorders? Psychol Med 2019; 49:1079-1088. [PMID: 30606278 PMCID: PMC6498787 DOI: 10.1017/s0033291718003896] [Citation(s) in RCA: 32] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/27/2018] [Revised: 11/02/2018] [Accepted: 11/27/2018] [Indexed: 11/30/2022]
Abstract
There is an enormous interest in identifying the causes of psychiatric disorders but there are considerable challenges in identifying which risks are genuinely causal. Traditionally risk factors have been inferred from observational designs. However, association with psychiatric outcome does not equate to causation. There are a number of threats that clinicians and researchers face in making causal inferences from traditional observational designs because adversities or exposures are not randomly allocated to individuals. Natural experiments provide an alternative strategy to randomized controlled trials as they take advantage of situations whereby links between exposure and other variables are separated by naturally occurring events or situations. In this review, we describe a growing range of different types of natural experiment and highlight that there is a greater confidence about findings where there is a convergence of findings across different designs. For example, exposure to hostile parenting is consistently found to be associated with conduct problems using different natural experiment designs providing support for this being a causal risk factor. Different genetically informative designs have repeatedly found that exposure to negative life events and being bullied are linked to later depression. However, for exposure to prenatal cigarette smoking, while findings from natural experiment designs are consistent with a causal effect on offspring lower birth weight, they do not support the hypothesis that intra-uterine cigarette smoking has a causal effect on attention-deficit/hyperactivity disorder and conduct problems and emerging findings highlight caution about inferring causal effects on bipolar disorder and schizophrenia.
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Affiliation(s)
- Anita Thapar
- Child & Adolescent Psychiatry Section, Division of Psychological Medicine and Clinical Neurosciences, MRC Centre for Neuropsychiatric Genetics and Genomics, Cardiff University School of Medicine, Hadyn Ellis Building, Maindy Road, Cathays, Cardiff, CF24 4HQ, UK
| | - Michael Rutter
- MRC SGDP Centre, Institute of Psychiatry, Psychology and Neuroscience, King's College, London, UK
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19
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Lowe DJ, Sasiadek JD, Coles AS, George TP. Cannabis and mental illness: a review. Eur Arch Psychiatry Clin Neurosci 2019; 269:107-120. [PMID: 30564886 PMCID: PMC6397076 DOI: 10.1007/s00406-018-0970-7] [Citation(s) in RCA: 132] [Impact Index Per Article: 26.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/01/2018] [Accepted: 12/12/2018] [Indexed: 12/30/2022]
Abstract
With the increasing push to legalize cannabis in Western nations, there is a need to gage the potential impact of this policy change on vulnerable populations, such as those with mental illness, including schizophrenia, mood, and anxiety disorders. This is particularly important as there are strong motives in these individuals to seek short-term reward (e.g., "getting high"). Nonetheless, data to support the beneficial effects of cannabis use in psychiatric populations are limited, and potential harms in patients with psychotic and mood disorders have been increasingly documented. This article reviews the effects of cannabis in people with mental illness. Then, we provide a reconciliation of the addiction vulnerability and allostatic hypotheses to explain co-morbidity addiction in mentally ill cannabis users, as well as to further aid in developing a rational framework for the assessment and treatment of problematic cannabis use in these patients.
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Affiliation(s)
- Darby J.E. Lowe
- Addictions Division, Centre for Addiction and Mental Health (CAMH),Institute of Medical Sciences, University of Toronto
| | | | | | - Tony P. George
- Addictions Division, Centre for Addiction and Mental Health (CAMH),Division and Brain and Therapeutics, Department of Psychiatry, University of Toronto
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20
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Degenhardt L, Saha S, Lim CCW, Aguilar-Gaxiola S, Al-Hamzawi A, Alonso J, Andrade LH, Bromet EJ, Bruffaerts R, Caldas-de-Almeida JM, de Girolamo G, Florescu S, Gureje O, Haro JM, Karam EG, Karam G, Kovess-Masfety V, Lee S, Lepine JP, Makanjuola V, Medina-Mora ME, Mneimneh Z, Navarro-Mateu F, Piazza M, Posada-Villa J, Sampson NA, Scott KM, Stagnaro JC, Have MT, Kendler KS, Kessler RC, McGrath JJ. The associations between psychotic experiences and substance use and substance use disorders: findings from the World Health Organization World Mental Health surveys. Addiction 2018; 113:924-934. [PMID: 29284197 PMCID: PMC5895500 DOI: 10.1111/add.14145] [Citation(s) in RCA: 44] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/22/2017] [Revised: 11/24/2017] [Accepted: 12/15/2017] [Indexed: 02/06/2023]
Abstract
BACKGROUND AND AIMS Prior research has found bidirectional associations between psychotic experiences (PEs) and selected substance use disorders. We aimed to extend this research by examining the bidirectional association between PEs and various types of substance use (SU) and substance use disorders (SUDs), and the influence of antecedent mental disorders on these associations. DESIGN, SETTING, PARTICIPANTS AND MEASUREMENTS We used data from the World Health Organization World Mental Health surveys. A total of 30 902 adult respondents across 18 countries were assessed for (a) six types of life-time PEs, (b) a range of types of SU and DSM-IV SUDs and (c) mental disorders using the Composite International Diagnostic Interview. Discrete-time survival analyses based on retrospective age-at-onset reports examined the bidirectional associations between PEs and SU/SUDs controlling for antecedent mental disorders. FINDINGS After adjusting for demographics, comorbid SU/SUDs and antecedent mental disorders, those with prior alcohol use disorders [odds ratio (OR) = 1.6, 95% confidence interval (CI) = 1.2-2.0], extra-medical prescription drug use (OR = 1.5, 95% CI = 1.1-1.9), alcohol use (OR = 1.4, 95% CI = 1.1-1.7) and tobacco use (OR = 1.3, 95% CI = 1.0-1.8) had increased odds of subsequent first onset of PEs. In contrast, those with temporally prior PEs had increased odds of subsequent onset of tobacco use (OR = 1.5, 95% CI = 1.2-1.9), alcohol use (OR = 1.3, 95% CI = 1.1-1.6) or cannabis use (OR = 1.3, 95% CI = 1.0-1.5) as well as of all substance use disorders (ORs ranged between 1.4 and 1.5). There was a dose response relationship between both count and frequency of PEs and increased subsequent odds of selected SU/SUDs. CONCLUSIONS Associations between psychotic experiences (PEs) and substance use/substance use disorders (SU/SUDs) are often bidirectional, but not all types of SU/SUDs are associated with PEs. These findings suggest that it is important to be aware of the presence of PEs within those with SUDs or at risk of SUDs, given the plausibility that they may each impact upon the other.
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Affiliation(s)
- Louisa Degenhardt
- National Drug and Alcohol Research Centre, University of New South Wales, Sydney, Australia
| | - Sukanta Saha
- Queensland Centre for Mental Health Research, and Queensland Brain Institute, The University of Queensland, St. Lucia, Queensland, Australia
| | - Carmen C. W. Lim
- Queensland Centre for Mental Health Research, and Queensland Brain Institute, The University of Queensland, St. Lucia, Queensland, Australia
| | - Sergio Aguilar-Gaxiola
- Center for Reducing Health Disparities, UC Davis Health System, Sacramento, California, USA
| | - Ali Al-Hamzawi
- College of Medicine, Al-Qadisiya University, Diwaniya governorate, Iraq
| | - Jordi Alonso
- Health Services Research Unit, IMIM-Hospital del Mar Medical Research Institute, Barcelona, Spain; Pompeu Fabra University (UPF), Barcelona, Spain; and CIBER en Epidemiología y Salud Pública (CIBERESP), Barcelona, Spain
| | - Laura H. Andrade
- Núcleo de Epidemiologia Psiquiátrica - LIM 23, Instituto de Psiquiatria Hospital das Clinicas da Faculdade de Medicina da Universidade de São Paulo
| | - Evelyn J. Bromet
- Department of Psychiatry, Stony Brook University School of Medicine, Stony Brook, New York, USA
| | - Ronny Bruffaerts
- Universitair Psychiatrisch Centrum - Katholieke Universiteit Leuven (UPC-KUL), Campus Gasthuisberg, Leuven, Belgium
| | - José M. Caldas-de-Almeida
- Lisbon Institute of Global Mental Health and Chronic Diseases Research Center (CEDOC), NOVA Medical School
- Faculdade de Ciências Médicas, Universidade Nova de Lisboa, Lisbon, Portugal
| | - Giovanni de Girolamo
- Unit of Epidemiological and Evaluation Psychiatry, Istituti di Ricovero e Cura a Carattere Scientifico (IRCCS)-St. John of God Clinical Research Centre, Via Pilastroni 4, Brescia, Italy
| | - Silvia Florescu
- National School of Public Health, Management and Professional Development, Bucharest, Romania
| | - Oye Gureje
- Department of Psychiatry, University College Hospital, Ibadan, Nigeria
| | - Josep M. Haro
- Parc Sanitari Sant Joan de Déu, CIBERSAM, Universitat de Barcelona, Sant Boi de Llobregat, Barcelona, Spain
| | - Elie G. Karam
- Department of Psychiatry and Clinical Psychology, Faculty of Medicine, Balamand University, Beirut, Lebanon; Department of Psychiatry and Clinical Psychology, St George Hospital University Medical Center, Beirut, Leban on; Institute for Development Research Advocacy and Applied Care (IDRAAC), Beirut, Lebanon
| | - Georges Karam
- Department of Psychiatry and Clinical Psychology, Faculty of Medicine, Balamand University, Beirut, Lebanon; Department of Psychiatry and Clinical Psychology, St George Hospital University Medical Center, Beirut, Leban on; Institute for Development Research Advocacy and Applied Care (IDRAAC), Beirut, Lebanon
| | - Viviane Kovess-Masfety
- EHESP Dpt MéTis Epidémiologie et biostatistiques pour la décision en santé publique /Laboratoire Psychopathologie et Processus de Santé (EA 4057) Université Paris Descartes EHESP School for Public Health; Dpt Health Epidemiology and biostatistics for decision making in public health / EA 4057 Paris Descartes University
| | - Sing Lee
- Department of Psychiatry, Chinese University of Hong Kong, Tai Po, Hong Kong
| | - Jean-Pierre Lepine
- Hôpital Lariboisière-Fernand Widal, Assistance Publique Hôpitaux de Paris; Universités Paris Descartes-Paris Diderot; INSERM UMR-S 1144, Paris, France
| | - Victor Makanjuola
- Department of Psychiatry, University College Hospital, Ibadan, Nigeria
| | | | - Zeina Mneimneh
- Survey Research Center, University of Michigan, Ann Arbor, MI, USA
| | - Fernando Navarro-Mateu
- UDIF-SM, Subdirección General de Planificación, Innovación y Cronicidad, Servicio Murciano de Salud. IMIB-Arrixaca. CIBERESP-Murcia, Murcia, Spain
| | - Marina Piazza
- Universidad Cayetano Heredia, Lima, Peru; National Institute of Health, Lima, Peru
| | - José Posada-Villa
- Colegio Mayor de Cundinamarca University, Faculty of Social Sciences, Bogota, Colombia
| | - Nancy A. Sampson
- Department of Health Care Policy, Harvard Medical School, Boston, Massachusetts, USA
| | - Kate M. Scott
- Department of Psychological Medicine, University of Otago, Dunedin, Otago, New Zealand
| | - Juan C. Stagnaro
- Departamento de Psiquiatría y Salud Mental, Facultad de Medicina, Universidad de Buenos Aires, Argentina
| | - Margreet Ten Have
- Trimbos-Instituut, Netherlands Institute of Mental Health and Addiction, Utrecht, Netherlands
| | | | - Ronald C. Kessler
- Department of Health Care Policy, Harvard Medical School, Boston, Massachusetts, USA
| | - John J. McGrath
- Queensland Centre for Mental Health Research, and Queensland Brain Institute, University of Queensland, St. Lucia, Queensland, Australia; and National Centre for Register-based Research, Aarhus BSS, Aarhus University, Aarhus, Denmark
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Elmore JS, Baumann MH. Repeated Exposure to the "Spice" Cannabinoid JWH-018 Induces Tolerance and Enhances Responsiveness to 5-HT 1A Receptor Stimulation in Male Rats. Front Psychiatry 2018. [PMID: 29535650 PMCID: PMC5835089 DOI: 10.3389/fpsyt.2018.00055] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
Naphthalen-1-yl-(1-pentylindol-3-yl)methanone (JWH-018) is a synthetic compound found in psychoactive "spice" products that activates cannabinoid receptors. Preclinical evidence suggests that exposure to synthetic cannabinoids increases 5-HT2A/2C receptor function in the brain, an effect which might contribute to psychotic symptoms. Here, we hypothesized that repeated exposures to JWH-018 would enhance behavioral responsiveness to the 5-HT2A/2C receptor agonist DOI. Male Sprague-Dawley rats fitted with subcutaneously (sc) temperature transponders received daily injections of JWH-018 (1.0 mg/kg, sc) or its vehicle for seven consecutive days. Body temperature and catalepsy scores were determined at 1, 2, and 4 h post-injection each day. At 1 and 7 days after the final repeated treatment, rats received a challenge injection of either DOI (0.1 mg/kg, sc) or the 5-HT1A receptor agonist 8-OH-DPAT (0.3 mg/kg, sc), then temperature and behavioral responses were assessed. Behaviors induced by DOI included wet dog shakes and back muscle contractions (i.e., skin jerks), while behaviors induced by 8-OH-DPAT included ambulation, forepaw treading, and flat body posture. On the first day of repeated treatment, JWH-018 produced robust hypothermia and catalepsy which lasted up to 4 h, and these effects were significantly blunted by day 7 of treatment. Repeated exposure to JWH-018 did not affect behaviors induced by DOI, but behavioral and hypothermic responses induced by 8-OH-DPAT were significantly augmented 1 day after cessation of JWH-018 treatment. Collectively, our findings show that repeated treatment with JWH-018 produces tolerance to its hypothermic and cataleptic effects, which is accompanied by transient enhancement of 5-HT1A receptor sensitivity in vivo.
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Affiliation(s)
- Joshua S Elmore
- Designer Drug Research Unit, Intramural Research Program, National Institute on Drug Abuse, National Institutes of Health, Baltimore, MD, United States
| | - Michael H Baumann
- Designer Drug Research Unit, Intramural Research Program, National Institute on Drug Abuse, National Institutes of Health, Baltimore, MD, United States
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The clinical implications of legalizing marijuana: Are physician and non-physician providers prepared? Addict Behav 2017; 72:1-7. [PMID: 28319813 DOI: 10.1016/j.addbeh.2017.03.007] [Citation(s) in RCA: 53] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2016] [Revised: 02/09/2017] [Accepted: 03/08/2017] [Indexed: 11/23/2022]
Abstract
INTRODUCTION Passage of voter-driven marijuana reform laws signals a shift in public attitudes for marijuana use. For providers, legalization may necessitate practice modifications, particularly regarding patient-provider conversations about use and risk. We examined healthcare providers' knowledge of marijuana laws and health implications, professional practice behaviors, and attitudes about training. MATERIALS AND METHODS We surveyed 114 Colorado-based providers who care for children, adolescents, pregnant and breastfeeding women using a Venue-Day-Time survey methodology throughout Colorado. The survey captured providers' (e.g., physicians, nurses, medical assistants) knowledge of state marijuana laws, risk perceptions, counseling practices, and continued training needs. RESULTS Providers were knowledgeable about marijuana laws, cautious supporting legalization, and perceived moderate to high risks, particularly for certain groups. About 50% of providers working with adolescents and pregnant or breastfeeding women assessed marijuana use "every" or "most" visits; 23% of those working with children reported such behavior. Conversations about specific risks varied between groups. Few providers felt completely knowledgeable about marijuana health risks and lacked confidence talking to patients about this issue. CONCLUSIONS Providers frequently assess patients' marijuana use; however, they are uncomfortable and inconsistent talking to patients about specific marijuana health effects. Additional education is warranted, particularly as it relates to talking to patients about the danger of second hand smoke exposure, underage use, safe storage, and the over-consumption of edibles.
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Fischer B, Russell C, Sabioni P, van den Brink W, Le Foll B, Hall W, Rehm J, Room R. Lower-Risk Cannabis Use Guidelines: A Comprehensive Update of Evidence and Recommendations. Am J Public Health 2017; 107:e1-e12. [PMID: 28644037 PMCID: PMC5508136 DOI: 10.2105/ajph.2017.303818] [Citation(s) in RCA: 256] [Impact Index Per Article: 36.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/25/2017] [Indexed: 01/08/2023]
Abstract
BACKGROUND Cannabis use is common in North America, especially among young people, and is associated with a risk of various acute and chronic adverse health outcomes. Cannabis control regimes are evolving, for example toward a national legalization policy in Canada, with the aim to improve public health, and thus require evidence-based interventions. As cannabis-related health outcomes may be influenced by behaviors that are modifiable by the user, evidence-based Lower-Risk Cannabis Use Guidelines (LRCUG)-akin to similar guidelines in other health fields-offer a valuable, targeted prevention tool to improve public health outcomes. OBJECTIVES To systematically review, update, and quality-grade evidence on behavioral factors determining adverse health outcomes from cannabis that may be modifiable by the user, and translate this evidence into revised LRCUG as a public health intervention tool based on an expert consensus process. SEARCH METHODS We used pertinent medical search terms and structured search strategies, to search MEDLINE, EMBASE, PsycINFO, Cochrane Library databases, and reference lists primarily for systematic reviews and meta-analyses, and additional evidence on modifiable risk factors for adverse health outcomes from cannabis use. SELECTION CRITERIA We included studies if they focused on potentially modifiable behavior-based factors for risks or harms for health from cannabis use, and excluded studies if cannabis use was assessed for therapeutic purposes. DATA COLLECTION AND ANALYSIS We screened the titles and abstracts of all studies identified by the search strategy and assessed the full texts of all potentially eligible studies for inclusion; 2 of the authors independently extracted the data of all studies included in this review. We created Preferred Reporting Items for Systematic Reviews and Meta-Analyses flow-charts for each of the topical searches. Subsequently, we summarized the evidence by behavioral factor topic, quality-graded it by following standard (Grading of Recommendations Assessment, Development, and Evaluation; GRADE) criteria, and translated it into the LRCUG recommendations by the author expert collective on the basis of an iterative consensus process. MAIN RESULTS For most recommendations, there was at least "substantial" (i.e., good-quality) evidence. We developed 10 major recommendations for lower-risk use: (1) the most effective way to avoid cannabis use-related health risks is abstinence, (2) avoid early age initiation of cannabis use (i.e., definitively before the age of 16 years), (3) choose low-potency tetrahydrocannabinol (THC) or balanced THC-to-cannabidiol (CBD)-ratio cannabis products, (4) abstain from using synthetic cannabinoids, (5) avoid combusted cannabis inhalation and give preference to nonsmoking use methods, (6) avoid deep or other risky inhalation practices, (7) avoid high-frequency (e.g., daily or near-daily) cannabis use, (8) abstain from cannabis-impaired driving, (9) populations at higher risk for cannabis use-related health problems should avoid use altogether, and (10) avoid combining previously mentioned risk behaviors (e.g., early initiation and high-frequency use). AUTHORS' CONCLUSIONS Evidence indicates that a substantial extent of the risk of adverse health outcomes from cannabis use may be reduced by informed behavioral choices among users. The evidence-based LRCUG serve as a population-level education and intervention tool to inform such user choices toward improved public health outcomes. However, the LRCUG ought to be systematically communicated and supported by key regulation measures (e.g., cannabis product labeling, content regulation) to be effective. All of these measures are concretely possible under emerging legalization regimes, and should be actively implemented by regulatory authorities. The population-level impact of the LRCUG toward reducing cannabis use-related health risks should be evaluated. Public health implications. Cannabis control regimes are evolving, including legalization in North America, with uncertain impacts on public health. Evidence-based LRCUG offer a potentially valuable population-level tool to reduce the risk of adverse health outcomes from cannabis use among (especially young) users in legalization contexts, and hence to contribute to improved public health outcomes.
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Affiliation(s)
- Benedikt Fischer
- Benedikt Fischer, Cayley Russell, Pamela Sabioni, and Jürgen Rehm are with the Institute for Mental Health Policy Research, Centre for Addiction and Mental Health, University of Toronto, Toronto, Ontario. Wim van den Brink is with the Amsterdam Institute for Addiction Research, Department of Psychiatry, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands. Bernard Le Foll is with the Translational Addiction Research Laboratory, Campbell Family Mental Health Research Institute, Centre for Addiction and Mental Health, Toronto. Wayne Hall is with the Centre for Youth Substance Abuse Research, Faculty of Health and Behavioural Sciences, University of Queensland, Brisbane, Australia. Robin Room is with the Centre for Alcohol Policy Research, La Trobe University, Melbourne, Australia
| | - Cayley Russell
- Benedikt Fischer, Cayley Russell, Pamela Sabioni, and Jürgen Rehm are with the Institute for Mental Health Policy Research, Centre for Addiction and Mental Health, University of Toronto, Toronto, Ontario. Wim van den Brink is with the Amsterdam Institute for Addiction Research, Department of Psychiatry, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands. Bernard Le Foll is with the Translational Addiction Research Laboratory, Campbell Family Mental Health Research Institute, Centre for Addiction and Mental Health, Toronto. Wayne Hall is with the Centre for Youth Substance Abuse Research, Faculty of Health and Behavioural Sciences, University of Queensland, Brisbane, Australia. Robin Room is with the Centre for Alcohol Policy Research, La Trobe University, Melbourne, Australia
| | - Pamela Sabioni
- Benedikt Fischer, Cayley Russell, Pamela Sabioni, and Jürgen Rehm are with the Institute for Mental Health Policy Research, Centre for Addiction and Mental Health, University of Toronto, Toronto, Ontario. Wim van den Brink is with the Amsterdam Institute for Addiction Research, Department of Psychiatry, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands. Bernard Le Foll is with the Translational Addiction Research Laboratory, Campbell Family Mental Health Research Institute, Centre for Addiction and Mental Health, Toronto. Wayne Hall is with the Centre for Youth Substance Abuse Research, Faculty of Health and Behavioural Sciences, University of Queensland, Brisbane, Australia. Robin Room is with the Centre for Alcohol Policy Research, La Trobe University, Melbourne, Australia
| | - Wim van den Brink
- Benedikt Fischer, Cayley Russell, Pamela Sabioni, and Jürgen Rehm are with the Institute for Mental Health Policy Research, Centre for Addiction and Mental Health, University of Toronto, Toronto, Ontario. Wim van den Brink is with the Amsterdam Institute for Addiction Research, Department of Psychiatry, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands. Bernard Le Foll is with the Translational Addiction Research Laboratory, Campbell Family Mental Health Research Institute, Centre for Addiction and Mental Health, Toronto. Wayne Hall is with the Centre for Youth Substance Abuse Research, Faculty of Health and Behavioural Sciences, University of Queensland, Brisbane, Australia. Robin Room is with the Centre for Alcohol Policy Research, La Trobe University, Melbourne, Australia
| | - Bernard Le Foll
- Benedikt Fischer, Cayley Russell, Pamela Sabioni, and Jürgen Rehm are with the Institute for Mental Health Policy Research, Centre for Addiction and Mental Health, University of Toronto, Toronto, Ontario. Wim van den Brink is with the Amsterdam Institute for Addiction Research, Department of Psychiatry, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands. Bernard Le Foll is with the Translational Addiction Research Laboratory, Campbell Family Mental Health Research Institute, Centre for Addiction and Mental Health, Toronto. Wayne Hall is with the Centre for Youth Substance Abuse Research, Faculty of Health and Behavioural Sciences, University of Queensland, Brisbane, Australia. Robin Room is with the Centre for Alcohol Policy Research, La Trobe University, Melbourne, Australia
| | - Wayne Hall
- Benedikt Fischer, Cayley Russell, Pamela Sabioni, and Jürgen Rehm are with the Institute for Mental Health Policy Research, Centre for Addiction and Mental Health, University of Toronto, Toronto, Ontario. Wim van den Brink is with the Amsterdam Institute for Addiction Research, Department of Psychiatry, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands. Bernard Le Foll is with the Translational Addiction Research Laboratory, Campbell Family Mental Health Research Institute, Centre for Addiction and Mental Health, Toronto. Wayne Hall is with the Centre for Youth Substance Abuse Research, Faculty of Health and Behavioural Sciences, University of Queensland, Brisbane, Australia. Robin Room is with the Centre for Alcohol Policy Research, La Trobe University, Melbourne, Australia
| | - Jürgen Rehm
- Benedikt Fischer, Cayley Russell, Pamela Sabioni, and Jürgen Rehm are with the Institute for Mental Health Policy Research, Centre for Addiction and Mental Health, University of Toronto, Toronto, Ontario. Wim van den Brink is with the Amsterdam Institute for Addiction Research, Department of Psychiatry, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands. Bernard Le Foll is with the Translational Addiction Research Laboratory, Campbell Family Mental Health Research Institute, Centre for Addiction and Mental Health, Toronto. Wayne Hall is with the Centre for Youth Substance Abuse Research, Faculty of Health and Behavioural Sciences, University of Queensland, Brisbane, Australia. Robin Room is with the Centre for Alcohol Policy Research, La Trobe University, Melbourne, Australia
| | - Robin Room
- Benedikt Fischer, Cayley Russell, Pamela Sabioni, and Jürgen Rehm are with the Institute for Mental Health Policy Research, Centre for Addiction and Mental Health, University of Toronto, Toronto, Ontario. Wim van den Brink is with the Amsterdam Institute for Addiction Research, Department of Psychiatry, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands. Bernard Le Foll is with the Translational Addiction Research Laboratory, Campbell Family Mental Health Research Institute, Centre for Addiction and Mental Health, Toronto. Wayne Hall is with the Centre for Youth Substance Abuse Research, Faculty of Health and Behavioural Sciences, University of Queensland, Brisbane, Australia. Robin Room is with the Centre for Alcohol Policy Research, La Trobe University, Melbourne, Australia
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Control groups in paediatric epilepsy research: do first-degree cousins show familial effects? Epileptic Disord 2017; 19:49-58. [PMID: 28351825 DOI: 10.1684/epd.2017.0898] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
To determine whether first-degree cousins of children with idiopathic focal and genetic generalized epilepsies show any association across measures of cognition, behaviour, and brain structure. The presence/absence of associations addresses the question of whether and to what extent first-degree cousins may serve as unbiased controls in research addressing the cognitive, psychiatric, and neuroimaging features of paediatric epilepsies. Participants were children (aged 8-18) with epilepsy who had at least one first-degree cousin control enrolled in the study (n=37) and all enrolled cousin controls (n=100). Participants underwent neuropsychological assessment and brain imaging (cortical, subcortical, and cerebellar volumes), and parents completed the Child Behaviour Checklist (CBCL). Data (based on 42 outcome measures) from cousin controls were regressed on the corresponding epilepsy cognitive, behavioural, and imaging measures in a linear mixed model and case/control correlations were examined. Of the 42 uncorrected correlations involving cognitive, behavioural, and neuroimaging measures, only two were significant (p<0.05). The median correlation was 0.06. A test for whether the distribution of p values deviated from the null distribution under no association was not significant (p>0.25). Similar results held for the cognition/behaviour and brain imaging measures separately. Given the lack of association between cases and first-degree cousin performances on measures of cognition, behaviour, and neuroimaging, the results suggest a non-significant genetic influence on control group performance. First-degree cousins appear to be unbiased controls for cognitive, behavioural, and neuroimaging research in paediatric epilepsy.
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Nesvåg R, Reichborn-Kjennerud T, Gillespie NA, Knudsen GP, Bramness JG, Kendler KS, Ystrom E. Genetic and Environmental Contributions to the Association Between Cannabis Use and Psychotic-Like Experiences in Young Adult Twins. Schizophr Bull 2017; 43:644-653. [PMID: 27431873 PMCID: PMC5464089 DOI: 10.1093/schbul/sbw101] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
To investigate contributions of genetic and environmental risk factors and possible direction of causation for the relationship between symptoms of cannabis use disorders (CUD) and psychotic-like experiences (PLEs), a population-based sample of 2793 young adult twins (63.5% female, mean [range] age 28.2 [19-36] y) were assessed for symptoms of CUD and PLEs using the Composite International Diagnostic Interview. Latent risk of having symptoms of CUD or PLEs was modeled using Item Response Theory. Co-twin control analysis was performed to investigate effect of familiar confounding for the association between symptoms of CUD and PLEs. Biometric twin models were fitted to estimate the heritability, genetic and environmental correlations, and direction for the association. Lifetime use of cannabis was reported by 10.4 % of the twins, and prevalence of PLEs ranged from 0.1% to 2.2%. The incidence rate ratio of PLEs due to symptoms of CUD was 6.3 (95% CI, 3.9, 10.2) in the total sample and 3.5 (95% CI, 1.5, 8.2) within twin pairs. Heritability estimates for symptoms of CUD were 88% in men and women, and for PLEs 77% in men and 43% in women. The genetic and environmental correlations between symptoms of CUD and PLEs were 0.55 and 0.52, respectively. The model allowing symptoms of CUD to cause PLEs had a better fit than models specifying opposite or reciprocal directions of causation. The association between symptoms of CUD and PLEs is explained by shared genetic and environmental factors and direct effects from CUD to risk for PLEs.
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Affiliation(s)
- Ragnar Nesvåg
- Department of Mental Disorders, Norwegian Institute of Public Health, Oslo, Norway;,Department of Psychiatric Research, Diakonhjemmet Hospital, Oslo, Norway
| | - Ted Reichborn-Kjennerud
- Department of Mental Disorders, Norwegian Institute of Public Health, Oslo, Norway;,Institute of Clinical Medicine, University of Oslo, Oslo, Norway
| | - Nathan A. Gillespie
- Virginia Institute for Psychiatric and Behavioral Genetics and Departments of Psychiatry, Virginia Commonwealth University, Richmond, VA
| | - Gun Peggy Knudsen
- Department of Mental Disorders, Norwegian Institute of Public Health, Oslo, Norway
| | - Jørgen G. Bramness
- The Norwegian Centre for Addiction Research, University of Oslo, Oslo, Norway
| | - Kenneth S. Kendler
- Virginia Institute for Psychiatric and Behavioral Genetics and Departments of Psychiatry, Virginia Commonwealth University, Richmond, VA
| | - Eivind Ystrom
- Department of Mental Disorders, Norwegian Institute of Public Health, Oslo, Norway;,Department of Psychology, University of Oslo, Oslo, Norway;,School of Pharmacy, University of Oslo, Oslo, Norway
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Weiss SRB, Howlett KD, Baler RD. Building smart cannabis policy from the science up. THE INTERNATIONAL JOURNAL OF DRUG POLICY 2017; 42:39-49. [PMID: 28189459 PMCID: PMC5404989 DOI: 10.1016/j.drugpo.2017.01.007] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2016] [Revised: 12/21/2016] [Accepted: 01/09/2017] [Indexed: 12/12/2022]
Abstract
Social attitudes and cultural norms around the issue of substance abuse are shifting rapidly around the world, leading to complex and unpredictable consequences. On the positive side, efforts to more intensely disseminate the scientific evidence for the many connections between chronic substance use and the emergence of measurable and discrete brain dysfunctions, has ushered in an evolving climate of acceptance and a new era of improved access to more effective interventions, at least in the United States. On the negative side, there has been a steady erosion in the public perception of the harms associated with the use of popular drugs, especially cannabis. This worrisome trend has sprouted at the convergence of several forces that have combined, more or less fortuitously, to effectively change long-standing policies away from prohibition and toward decriminalization or legalization. These forces include the outsized popularity of the cannabis plant among recreational users, the unflagging campaign by corporate lobbyists and patient advocates to mainstream its medicinal use, and the honest realization in some quarters of the deleterious impact of the drug war and its draconian cannabis laws, in particular, on society's most vulnerable populations. Updating drug policies is a desirable goal, and significant changes may indeed be warranted. However, there is a real concern when policy changes are hurriedly implemented without the required input from the medical, scientific, or policy research communities. Regardless of how well intentioned, such initiatives are bound to magnify the potential for unintended adverse consequences in the form of far ranging health and social costs. To minimize this risk, science must be front and center in this important policy debate. Here, we review the state of the science on cannabis and cannabinoid health effects, both adverse and therapeutic. We focus on the prevalence of use in different populations, the mechanisms by which cannabis exerts its effects (i.e., via the endocannabinoid system), and the double-edged potential of this system to inspire new medications, on one hand, and to cause short and long term harmful effects on the other. By providing knowledge of cannabis' broad ranging effects, we hope to enable better decision making regarding cannabis legislation and policy implementation.
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Affiliation(s)
- Susan R B Weiss
- National Institute on Drug Abuse, National Institutes of Health, United States.
| | - Katia D Howlett
- National Institute on Drug Abuse, National Institutes of Health, United States
| | - Ruben D Baler
- National Institute on Drug Abuse, National Institutes of Health, United States
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Balon R. Clinical Factor 2015. PSYCHOTHERAPY AND PSYCHOSOMATICS 2017; 85:327-336. [PMID: 27744435 DOI: 10.1159/000448788] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/31/2016] [Accepted: 08/01/2016] [Indexed: 11/19/2022]
Affiliation(s)
- Richard Balon
- Department of Psychiatry and Behavioral Neurosciences and Department of Anesthesiology, Wayne State University School of Medicine, Detroit, Mich., USA
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Maccarrone M, Maldonado R, Casas M, Henze T, Centonze D. Cannabinoids therapeutic use: what is our current understanding following the introduction of THC, THC:CBD oromucosal spray and others? Expert Rev Clin Pharmacol 2017; 10:443-455. [PMID: 28276775 DOI: 10.1080/17512433.2017.1292849] [Citation(s) in RCA: 43] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
INTRODUCTION The complexity of the endocannabinoid (eCB) system is becoming better understood and new drivers of eCB signaling are emerging. Modulation of the activities of the eCB system can be therapeutic in a number of diseases. Research into the eCB system has been paralleled by the development of agents that interact with cannabinoid receptors. In this regard it should be remembered that herbal cannabis contains a myriad of active ingredients, and the individual cannabinoids have quite distinct biological activities requiring independent studies. Areas covered: This article reviews the most important current data involving the eCB system in relation to human diseases, to reflect the present (based mainly on the most used prescription cannabinoid medicine, THC/CBD oromucosal spray) and potential future uses of cannabinoid-based therapy. Expert commentary: From the different therapeutic possibilities, THC/CBD oromucosal spray has been in clinical use for approximately five years in numerous countries world-wide for the management of multiple sclerosis (MS)-related moderate to severe resistant spasticity. Clinical trials have confirmed its efficacy and tolerability. Other diseases in which different cannabinoids are currently being investigated include various pain states, Alzheimer's disease, Parkinson's disease, Huntington's disease and epilepsy. The continued characterization of individual cannabinoids in different diseases remains important.
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Affiliation(s)
- Mauro Maccarrone
- a Department of Medicine , Campus Bio-Medico University of Rome , Rome , Italy.,b Laboratory of Lipid Neurochemistry, European Center for Brain Research/IRCCS Santa Lucia Foundation , Rome , Italy
| | - Rafael Maldonado
- c Laboratori de Neurofarmacologia, Departament de Ciències Experimentals i de la Salut (CEXS), Facultat de Ciències de la Salut i de la Vida , Universitat Pompeu Fabra , Barcelona , Spain
| | - Miguel Casas
- d Servicio de Psiquiatría , Hospital Universitari Vall d'Hebron , Barcelona , Spain.,e Departamento de Psiquiatría y Medicina Legal , Universitat Autònoma de Barcelona , Barcelona , Spain.,f CIBERSAM , Barcelona , Spain
| | - Thomas Henze
- g Passauer Wolf Reha-Zentrum Nittenau , Nittenau , Germany
| | - Diego Centonze
- h Multiple Sclerosis Clinical and Research Center, Tor Vergata University, Rome & Unit of Neurology , IRCCS Istituto Neurologico Mediterraneo Neuromed , Pozzilli , Italy
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Abstract
Prevalence of psychiatric disorders continues to rise globally, yet remission rates and patient outcome remain less than ideal. As a result, novel treatment approaches for these disorders are necessary to decrease societal economic burden, as well as increase individual functioning. The recent discovery of the endocannabinoid system has provided an outlet for further research into its role in psychiatric disorders, because efficacy of targeted treatments have been demonstrated in medical illnesses, including cancers, neuropathic pain, and multiple sclerosis. The present review will investigate the role of the endocannabinoid system in psychiatric disorders, specifically schizophrenia, depressive, anxiety, and posttraumatic stress disorders, as well as attention-deficit hyperactivity disorder. Controversy remains in prescribing medicinal cannabinoid treatments due to the fear of adverse effects. However, one must consider all potential limitations when determining the safety and tolerability of cannabinoid products, specifically cannabinoid content (ie, Δ-tetrahydrocannabinol vs cannabidiol) as well as study design. The potential efficacy of cannabinoid treatments in the psychiatric population is an emerging topic of interest that provides potential value going forward in medicine.
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A Study of the Impact of Cannabis on Doses of Discharge Antipsychotic Medication in Individuals with Schizophrenia or Schizoaffective Disorder. Psychiatr Q 2016; 87:729-737. [PMID: 26875104 DOI: 10.1007/s11126-016-9426-2] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Abstract
Patients with schizophrenia or schizoaffective disorder have a high prevalence of comorbid cannabis use disorder (CUD). CUD has been associated with poorer outcomes in patients. We compared doses of antipsychotic medications at the time of discharge from hospital among inpatients with schizophrenia or schizoaffective disorder with or without concurrent cannabis use. We reviewed the medical records of patients (N = 8157) with schizophrenia or schizoaffective disorder discharged from the hospital between 2008 and 2012. The patients were divided into two groups; those with urine drug tests positive for cannabis and those negative for cannabis. Doses of antipsychotic medications were converted to chlorpromazine equivalents. Bivariate analyses were done with Student's t test for continuous variables and χ 2 test for categorical variables. Linear regression was carried out to adjust for potential confounders. Unadjusted analysis revealed that the cannabis positive group was discharged on lower doses of antipsychotic medication compared with the cannabis negative group (geometric mean chlorpromazine equivalent doses 431.22 ± 2.20 vs 485.18 ± 2.21; P < 0.001). However, the difference in geometric mean chlorpromazine equivalent doses between the two groups was no longer significant after adjusting for sex, age, race, and length of stay (geometric mean difference 0.99; 95 % CI 0.92-1.10). Though limited by lack of information on duration, amount and severity of cannabis use, as well as inability to control for other non-antipsychotic medications, our study suggests that cannabis use did not significantly impact on doses of antipsychotics required during the periods of acute exacerbation in patients with schizophrenia or schizoaffective disorder.
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Rentzsch J, Koller K, Kronenberg G. Letter to the Editor: Disentangling cause and effect in the relationship between cannabis and psychosis: are we there yet? Psychol Med 2016; 46:3061-3062. [PMID: 27452108 DOI: 10.1017/s0033291716001434] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- J Rentzsch
- Department of Psychiatry and Psychotherapy,Charité - Universitätsmedizin Berlin,Campus Mitte,Charitéplatz 1,10117 Berlin,Germany
| | - K Koller
- Department of Psychiatry and Psychotherapy,Charité - Universitätsmedizin Berlin,Campus Mitte,Charitéplatz 1,10117 Berlin,Germany
| | - G Kronenberg
- Department of Psychiatry and Psychotherapy,Charité - Universitätsmedizin Berlin,Campus Mitte,Charitéplatz 1,10117 Berlin,Germany
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Bogdan R, Winstone JMA, Agrawal A. Genetic and Environmental Factors Associated with Cannabis Involvement. CURRENT ADDICTION REPORTS 2016; 3:199-213. [PMID: 27642547 PMCID: PMC5019486 DOI: 10.1007/s40429-016-0103-1] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Approximately 50-70% of the variation in cannabis use and use disorders can be attributed to heritable factors. For cannabis use, the remaining variance can be parsed in to familial and person-specific environmental factors while for use disorders, only the latter contribute. While numerous candidate gene studies have identified the role of common variation influencing liability to cannabis involvement, replication has been elusive. To date, no genomewide association study has been sufficiently powered to identify significant loci. Despite this, studies adopting polygenic techniques and integrating genetic variation with neural phenotypes and measures of environmental risk, such as childhood adversity, are providing promising new leads. It is likely that the small effect sizes associated with variants related to cannabis involvement will only be robustly identified in substantially larger samples. Results of such large-scale efforts will provide valuable single variant targets for translational research in neurogenetic, pharmacogenetic and non-human animal models as well as polygenic risk indices that can be used to explore a host of other genetic hypotheses related to cannabis use and misuse.
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Affiliation(s)
- Ryan Bogdan
- BRAIN lab, Department of Psychological and Brain Sciences, Washington University in St. Louis
| | - Jonathan MA Winstone
- BRAIN lab, Department of Psychological and Brain Sciences, Washington University in St. Louis
| | - Arpana Agrawal
- Department of Psychiatry, Washington University in St Louis, St Louis, Missouri
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Mehta D, Tropf FC, Gratten J, Bakshi A, Zhu Z, Bacanu SA, Hemani G, Magnusson PKE, Barban N, Esko T, Metspalu A, Snieder H, Mowry BJ, Kendler KS, Yang J, Visscher PM, McGrath JJ, Mills MC, Wray NR, Hong Lee S. Evidence for Genetic Overlap Between Schizophrenia and Age at First Birth in Women. JAMA Psychiatry 2016; 73:497-505. [PMID: 27007234 PMCID: PMC5785705 DOI: 10.1001/jamapsychiatry.2016.0129] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
IMPORTANCE A recently published study of national data by McGrath et al in 2014 showed increased risk of schizophrenia (SCZ) in offspring associated with both early and delayed parental age, consistent with a U-shaped relationship. However, it remains unclear if the risk to the child is due to psychosocial factors associated with parental age or if those at higher risk for SCZ tend to have children at an earlier or later age. OBJECTIVE To determine if there is a genetic association between SCZ and age at first birth (AFB) using genetically informative but independently ascertained data sets. DESIGN, SETTING, AND PARTICIPANTS This investigation used multiple independent genome-wide association study data sets. The SCZ sample comprised 18 957 SCZ cases and 22 673 controls in a genome-wide association study from the second phase of the Psychiatric Genomics Consortium, and the AFB sample comprised 12 247 genotyped women measured for AFB from the following 4 community cohorts: Estonia (Estonian Genome Center Biobank, University of Tartu), the Netherlands (LifeLines Cohort Study), Sweden (Swedish Twin Registry), and the United Kingdom (TwinsUK). Schizophrenia genetic risk for each woman in the AFB community sample was estimated using genetic effects inferred from the SCZ genome-wide association study. MAIN OUTCOMES AND MEASURES We tested if SCZ genetic risk was a significant predictor of response variables based on published polynomial functions that described the relationship between maternal age and SCZ risk in offspring in Denmark. We substituted AFB for maternal age in these functions, one of which was corrected for the age of the father, and found that the fit was superior for the model without adjustment for the father's age. RESULTS We observed a U-shaped relationship between SCZ risk and AFB in the community cohorts, consistent with the previously reported relationship between SCZ risk in offspring and maternal age when not adjusted for the age of the father. We confirmed that SCZ risk profile scores significantly predicted the response variables (coefficient of determination R2 = 1.1E-03, P = 4.1E-04), reflecting the published relationship between maternal age and SCZ risk in offspring by McGrath et al in 2014. CONCLUSIONS AND RELEVANCE This study provides evidence for a significant overlap between genetic factors associated with risk of SCZ and genetic factors associated with AFB. It has been reported that SCZ risk associated with increased maternal age is explained by the age of the father and that de novo mutations that occur more frequently in the germline of older men are the underlying causal mechanism. This explanation may need to be revised if, as suggested herein and if replicated in future studies, there is also increased genetic risk of SCZ in older mothers.
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Affiliation(s)
- Divya Mehta
- The University of Queensland, Queensland Brain Institute, Brisbane, Queensland, Australia
| | - Felix C Tropf
- Department of Sociology/ICS, University of Groningen, The Netherlands
| | - Jacob Gratten
- The University of Queensland, Queensland Brain Institute, Brisbane, Queensland, Australia
| | - Andrew Bakshi
- The University of Queensland, Queensland Brain Institute, Brisbane, Queensland, Australia
| | - Zhihong Zhu
- The University of Queensland, Queensland Brain Institute, Brisbane, Queensland, Australia
| | - Silviu-Alin Bacanu
- Virginia Institute of Psychiatric and Behavioral Genetics, Virginia Commonwealth University, Richmond, Virginia, USA
- Department of Psychiatry, Virginia Commonwealth University, Richmond, Virginia, USA
| | - Gibran Hemani
- MRC Integrative Epidemiology Unit (IEU) at the University of Bristol, School of Social and Community Medicine, Bristol BS8 1TH, UK
| | - Patrik KE Magnusson
- Department of Medical Epidemiology and Biostatistics, Karolinska Institutet, Stockholm, Sweden
| | - Nicola Barban
- Nuffield College and Department of Sociology, University of Oxford, Oxford, England
| | - Tõnu Esko
- Estonian Genome Center, University of Tartu, Tartu, Estonia
| | | | - Harold Snieder
- Department of Epidemiology, University of Groningen, University Medical Center Groningen, Groningen, Netherlands
| | - Bryan J Mowry
- The University of Queensland, Queensland Brain Institute, Brisbane, Queensland, Australia
- Queensland Centre for Mental Health Research, Wacol, Queensland, Australia
| | - Kenneth S Kendler
- Virginia Institute of Psychiatric and Behavioral Genetics, Virginia Commonwealth University, Richmond, Virginia, USA
- Department of Psychiatry, Virginia Commonwealth University, Richmond, Virginia, USA
- Department of Human and Molecular Genetics, Virginia Commonwealth University, Richmond, Virginia, USA
| | - Jian Yang
- The University of Queensland, Queensland Brain Institute, Brisbane, Queensland, Australia
| | - Peter M Visscher
- The University of Queensland, Queensland Brain Institute, Brisbane, Queensland, Australia
| | - John J McGrath
- The University of Queensland, Queensland Brain Institute, Brisbane, Queensland, Australia
| | - Melinda C Mills
- Nuffield College and Department of Sociology, University of Oxford, Oxford, England
| | - Naomi R Wray
- The University of Queensland, Queensland Brain Institute, Brisbane, Queensland, Australia
| | - S Hong Lee
- The University of Queensland, Queensland Brain Institute, Brisbane, Queensland, Australia
- School of Environmental and Rural Science, The University of New England, Armidale, Australia
| | | | - LifeLines Cohort Study
- LifeLines Cohort Study, University of Groningen, University Medical Center Groningen, Groningen, Netherlands
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Gage SH, Hickman M, Zammit S. Association Between Cannabis and Psychosis: Epidemiologic Evidence. Biol Psychiatry 2016; 79:549-56. [PMID: 26386480 DOI: 10.1016/j.biopsych.2015.08.001] [Citation(s) in RCA: 213] [Impact Index Per Article: 26.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/31/2015] [Revised: 07/22/2015] [Accepted: 08/04/2015] [Indexed: 11/28/2022]
Abstract
Associations between cannabis use and psychotic outcomes are consistently reported, but establishing causality from observational designs can be problematic. We review the evidence from longitudinal studies that have examined this relationship and discuss the epidemiologic evidence for and against interpreting the findings as causal. We also review the evidence identifying groups at particularly high risk of developing psychosis from using cannabis. Overall, evidence from epidemiologic studies provides strong enough evidence to warrant a public health message that cannabis use can increase the risk of psychotic disorders. However, further studies are required to determine the magnitude of this effect, to determine the effect of different strains of cannabis on risk, and to identify high-risk groups particularly susceptible to the effects of cannabis on psychosis. We also discuss complementary epidemiologic methods that can help address these questions.
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Affiliation(s)
- Suzanne H Gage
- Medical Research Council Integrative Epidemiology Unit, University of Bristol, Bristol, United Kingdom.
| | - Matthew Hickman
- School of Social and Community Medicine, University of Bristol, Bristol, United Kingdom
| | - Stanley Zammit
- School of Social and Community Medicine, University of Bristol, Bristol, United Kingdom
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Bianconi F, Bonomo M, Marconi A, Kolliakou A, Stilo SA, Iyegbe C, Gurillo Muñoz P, Homayoun S, Mondelli V, Luzi S, Dazzan P, Prata D, La Cascia C, O'Connor J, David A, Morgan C, Murray RM, Lynskey M, Di Forti M. Differences in cannabis-related experiences between patients with a first episode of psychosis and controls. Psychol Med 2016; 46:995-1003. [PMID: 26670601 DOI: 10.1017/s0033291715002494] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
BACKGROUND Many studies have reported that cannabis use increases the risk of a first episode of psychosis (FEP). However, only a few studies have investigated the nature of cannabis-related experiences in FEP patients, and none has examined whether these experiences are similar in FEP and general populations. The aim of this study was to explore differences in self-reported cannabis experiences between FEP and non-psychotic populations. METHOD A total of 252 subjects, who met International Classification of Diseases (ICD)-10 criteria for FEP, and 217 controls who reported cannabis use were selected from the Genetics and Psychosis (GAP) study. The Medical Research Council Social Schedule and the Cannabis Experience Questionnaire were used to collect sociodemographic data and cannabis use information, respectively. RESULTS Both 'bad' and 'enjoyable' experiences were more commonly reported by FEP subjects than controls. Principal components factor analysis identified four components which explained 62.3% of the variance. Linear regression analysis on the whole sample showed that the type of cannabis used and beliefs about the effect of cannabis on health all contributed to determining the intensity and frequency of experiences. Linear regression analysis on FEP subjects showed that the duration of cannabis use and amount of money spent on cannabis were strongly related to the intensity and frequency of enjoyable experiences in this population. CONCLUSIONS These results suggest a higher sensitivity to cannabis effects among people who have suffered their first psychotic episode; this hypersensitivity results in them reporting both more 'bad' and 'enjoyable' experiences. The greater enjoyment experienced may provide an explanation of why FEP patients are more likely to use cannabis and to continue to use it despite experiencing an exacerbation of their psychotic symptoms.
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Affiliation(s)
- F Bianconi
- Department of Psychosis Studies,Institute of Psychiatry, Psychology and Neuroscience, King's College London,London,UK
| | - M Bonomo
- Department of Psychosis Studies,Institute of Psychiatry, Psychology and Neuroscience, King's College London,London,UK
| | - A Marconi
- Department of Paediatrics and Child and Adolescent Neuropsychiatry,'Sapienza' University of Rome,Rome,Italy
| | - A Kolliakou
- Biomedical Research Centre Nucleus,King's College London,London,UK
| | - S A Stilo
- Department of Psychosis Studies,Institute of Psychiatry, Psychology and Neuroscience, King's College London,London,UK
| | - C Iyegbe
- Department of Psychosis Studies,Institute of Psychiatry, Psychology and Neuroscience, King's College London,London,UK
| | | | - S Homayoun
- Department of Psychosis Studies,Institute of Psychiatry, Psychology and Neuroscience, King's College London,London,UK
| | - V Mondelli
- Department of Psychosis Studies,Institute of Psychiatry, Psychology and Neuroscience, King's College London,London,UK
| | - S Luzi
- Department of Psychosis Studies,Institute of Psychiatry, Psychology and Neuroscience, King's College London,London,UK
| | - P Dazzan
- Department of Psychosis Studies,Institute of Psychiatry, Psychology and Neuroscience, King's College London,London,UK
| | - D Prata
- Department of Neuroimaging,Institute of Psychiatry, Psychology and Neuroscience, King's College London,London,UK
| | - C La Cascia
- Department of Experimental Biomedicine and Clinical Neuroscience,University of Palermo,Palermo,Italy
| | - J O'Connor
- Department of Psychosis Studies,Institute of Psychiatry, Psychology and Neuroscience, King's College London,London,UK
| | - A David
- Department of Psychosis Studies,Institute of Psychiatry, Psychology and Neuroscience, King's College London,London,UK
| | - C Morgan
- Department of Psychosis Studies,Institute of Psychiatry, Psychology and Neuroscience, King's College London,London,UK
| | - R M Murray
- Department of Psychosis Studies,Institute of Psychiatry, Psychology and Neuroscience, King's College London,London,UK
| | - M Lynskey
- Addiction Department,Institute of Psychiatry, Psychology and Neuroscience, King's College London,London,UK
| | - M Di Forti
- Department of Psychosis Studies,Institute of Psychiatry, Psychology and Neuroscience, King's College London,London,UK
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Abstract
Cannabis use has been reported to increase the risk of developing schizophrenia and to worsen symptoms of the illness. Both of these outcomes might be attributable to the disruption by cannabis of the endogenous cannabinoid system's spatiotemporal regulation of the inhibitory circuitry in the prefrontal cortex that is essential for core cognitive processes, such as working memory, which are impaired in schizophrenia. In the healthy brain, the endocannabinoid 2-arachidonylglycerol 1) is synthesized by diacylglycerol lipase in pyramidal neurons; 2) travels retrogradely to nearby inhibitory axon terminals that express the primary type 1 cannabinoid receptor (CB1R); 3) binds to CB1R, which inhibits gamma-aminobutyric acid release from the cholecystokinin-containing population of interneurons; and 4) is metabolized by either monoglyceride lipase, which is located in the inhibitory axon terminal, or by α-β-hydrolase domain 6, which is co-localized presynaptically with diacylglycerol lipase. Investigations of the endogenous cannabinoid system in the prefrontal cortex of subjects with schizophrenia have found evidence of higher metabolism of 2-arachidonylglycerol, as well as both greater CB1R receptor binding and lower levels of CB1R messenger RNA and protein. Current views on the potential pathogenesis of these alterations, including disturbances in the development of the endogenous cannabinoid system, are discussed. In addition, how interactions between these alterations in the endocannabinoid system and those in other inhibitory neurons in the prefrontal cortex in subjects with schizophrenia might increase the liability to adverse outcomes with cannabis use is considered.
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Affiliation(s)
- David W. Volk
- Department of Psychiatry, University of Pittsburgh, Pittsburgh, PA 15213
| | - David A. Lewis
- Department of Psychiatry, University of Pittsburgh, Pittsburgh, PA 15213,Department of Neuroscience, University of Pittsburgh, Pittsburgh, PA 15213
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Abstract
Interest in the relationship between cannabis use and psychosis has increased dramatically in recent years, in part because of concerns related to the growing availability of cannabis and potential risks to health and human functioning. There now exists a plethora of scientific articles addressing this issue, but few provide a clear verdict about the causal nature of the cannabis-psychosis association. Here, we review recent research reports on cannabis and psychosis, giving particular attention to how each report provides evidence relating to two hypotheses: (1) cannabis as a contributing cause and (2) shared vulnerability. Two primary kinds of data are brought to bear on this issue: studies done with schizophrenic patients and studies of first-episode psychosis. Evidence reviewed here suggests that cannabis does not in itself cause a psychosis disorder. Rather, the evidence leads us to conclude that both early use and heavy use of cannabis are more likely in individuals with a vulnerability to psychosis. The role of early and heavy cannabis use as a prodromal sign merits further examination, along with a variety of other problem behaviors (e.g., early or heavy use of cigarettes or alcohol and poor school performance). Future research studies that focus exclusively on the cannabis-psychosis association will therefore be of little value in our quest to better understand psychosis and how and why it occurs.
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Affiliation(s)
- Charles Ksir
- Department of Psychology and Neuroscience Program, University of Wyoming, Laramie, WY, USA
| | - Carl L Hart
- Division on Substance Abuse, New York State Psychiatric Institute, Columbia University, 1051 Riverside Dr., Unit 120, New York, NY, 10032, USA. .,Department of Psychology, Columbia College, 1190 Amsterdam Ave, Schermerhorn #406, New York, NY, 10027, USA. .,Department of Psychiatry, Columbia University, 1051 Riverside Dr., Unit 120, New York, NY, 10032, USA. .,Brocher Foundation, Geneva, Switzerland.
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38
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Does Cannabis Cause, Exacerbate or Ameliorate Psychiatric Disorders? An Oversimplified Debate Discussed. Neuropsychopharmacology 2016; 41:393-401. [PMID: 26286840 PMCID: PMC5130141 DOI: 10.1038/npp.2015.251] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/24/2015] [Revised: 08/14/2015] [Accepted: 08/17/2015] [Indexed: 12/13/2022]
Abstract
There have been extensive policy shifts in the legality of recreational and therapeutic use of cannabis in the United States, as well as a steady increase in the number of people using the drug on a regular basis. Given these rapid societal changes, defining what is known scientifically about the consequences of cannabis use on mental health takes on added public health significance. The purpose of this circumspectives piece is to discuss evidence of cannabis' effects on two psychiatric conditions: post-traumatic stress disorder and psychotic disorders. Dr Haney and Dr Evins will discuss two viewpoints regarding the benefit and harm of cannabis use for these conditions, while outlining what remains unproven and requires further testing to move the field forward.
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Moran LV, Masters GA, Pingali S, Cohen BM, Liebson E, Rajarethinam R, Ongur D. Prescription stimulant use is associated with earlier onset of psychosis. J Psychiatr Res 2015; 71:41-7. [PMID: 26522870 PMCID: PMC4630672 DOI: 10.1016/j.jpsychires.2015.09.012] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/08/2015] [Revised: 08/14/2015] [Accepted: 09/17/2015] [Indexed: 10/23/2022]
Abstract
A childhood history of attention deficit hyperactivity disorder (ADHD) is common in psychotic disorders, yet prescription stimulants may interact adversely with the physiology of these disorders. Specifically, exposure to stimulants leads to long-term increases in dopamine release. We therefore hypothesized that individuals with psychotic disorders previously exposed to prescription stimulants will have an earlier onset of psychosis. Age of onset of psychosis (AOP) was compared in individuals with and without prior exposure to prescription stimulants while controlling for potential confounding factors. In a sample of 205 patients recruited from an inpatient psychiatric unit, 40% (n = 82) reported use of stimulants prior to the onset of psychosis. Most participants were prescribed stimulants during childhood or adolescence for a diagnosis of ADHD. AOP was significantly earlier in those exposed to stimulants (20.5 vs. 24.6 years stimulants vs. no stimulants, p < 0.001). After controlling for gender, IQ, educational attainment, lifetime history of a cannabis use disorder or other drugs of abuse, and family history of a first-degree relative with psychosis, the association between stimulant exposure and earlier AOP remained significant. There was a significant gender × stimulant interaction with a greater reduction in AOP for females, whereas the smaller effect of stimulant use on AOP in males did not reach statistical significance. In conclusion, individuals with psychotic disorders exposed to prescription stimulants had an earlier onset of psychosis, and this relationship did not appear to be mediated by IQ or cannabis.
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Affiliation(s)
- Lauren V. Moran
- McLean Hospital, Psychotic Disorders Division, Belmont, Massachusetts; Harvard Medical School,Correspondence to Dr. Lauren Moran, McLean Hospital, Admissions Building, 115 Mill Street, Belmont, MA 02478, Office: (617) 855-3395,
| | - Grace A. Masters
- McLean Hospital, Psychotic Disorders Division, Belmont, Massachusetts; Harvard Medical School
| | - Samira Pingali
- McLean Hospital, Psychotic Disorders Division, Belmont, Massachusetts; Harvard Medical School
| | - Bruce M. Cohen
- McLean Hospital, Psychotic Disorders Division, Belmont, Massachusetts; Harvard Medical School
| | - Elizabeth Liebson
- McLean Hospital, Psychotic Disorders Division, Belmont, Massachusetts; Harvard Medical School
| | - R.P. Rajarethinam
- McLean Hospital, Psychotic Disorders Division, Belmont, Massachusetts; Harvard Medical School
| | - Dost Ongur
- McLean Hospital, Psychotic Disorders Division, Belmont, Massachusetts; Harvard Medical School
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Kendler KS, Lönn SL, Sundquist J, Sundquist K. Smoking and schizophrenia in population cohorts of Swedish women and men: a prospective co-relative control study. Am J Psychiatry 2015; 172:1092-100. [PMID: 26046339 PMCID: PMC4651774 DOI: 10.1176/appi.ajp.2015.15010126] [Citation(s) in RCA: 87] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
OBJECTIVE The purpose of this study was to clarify the causes of the smoking-schizophrenia association. METHOD Using Cox proportional hazard and co-relative control models, the authors predicted future risk for a diagnosis of schizophrenia or nonaffective psychosis from the smoking status of 1,413,849 women and 233,879 men from, respectively, the Swedish birth and conscript registries. RESULTS Smoking was assessed in women at a mean age of 27 and in men at a mean age of 18. The mean age at end of follow-up was 46 for women and 26 for men. Hazard ratios for first-onset schizophrenia were elevated both for light smoking (2.21 [95% CI=1.90-2.56] for women and 2.15 [95% CI=1.25-3.44] for men) and heavy smoking (3.45 [95% CI=2.95-4.03] for women and 3.80 [95% CI=1.19-6.60] for men). These associations did not decline when schizophrenia onsets 3-5 years after smoking assessment were censored. When age, socioeconomic status, and drug abuse were controlled for, hazard ratios declined only modestly in both samples. Women who smoked into late pregnancy had a much higher risk for schizophrenia than those who quit early. Hazard ratios predicting nonaffective psychosis in the general population, in cousins, in half siblings, and in full siblings discordant for heavy smoking were, respectively, 2.67, 2.71, 2.54, and 2.18. A model utilizing all relative pairs predicted a hazard ratio of 1.69 (95% CI=1.17-2.44) for nonaffective psychosis in the heavy-smoking member of discordant monozygotic twin pairs. CONCLUSIONS Smoking prospectively predicts risk for schizophrenia. This association does not arise from smoking onset during a schizophrenic prodrome and demonstrates a clear dose-response relationship. While little of this association is explained by epidemiological confounders, a portion arises from common familial/genetic risk factors. However, in full siblings and especially monozygotic twins discordant for smoking, risk for nonaffective psychosis is appreciably higher in the smoking member. These results can help in evaluating the plausibility of various etiological hypotheses for the smoking-schizophrenia association.
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The aetiology of schizophrenia: what have the Swedish Medical Registers taught us? Soc Psychiatry Psychiatr Epidemiol 2015; 50:1471-9. [PMID: 26088681 DOI: 10.1007/s00127-015-1081-7] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/15/2015] [Accepted: 06/10/2015] [Indexed: 01/01/2023]
Abstract
OBJECTIVE To review the last thirty years of studies that, using Swedish population registers, have added to our understanding of the aetiology of schizophrenia SAMPLE INCLUDED/METHODS: A literature search was performed to systematically review all studies that using Swedish Population based registers have investigated the aetiology of schizophrenia. Key authors in the field, predominately from Swedish institutions, were additionally contacted and key journals hand searched, for missing references. A quality assessment methodological review was then conducted on each study. Data was extracted and tabulated on identified aetiological themes RESULTS 61 articles were included corresponding to 10 identified aetiological themes. Although the majority of included studies were retrospective cohort studies, case control studies were also included where they used population based registers. Confirming previous research, schizophrenia was found to have a multi-factorial aetiological basis with pregnancy and birth factors, parental age, social adversity, genetics, substance misuse, migration and ethnicity, personality, non-psychiatric co-morbidity, psychiatric history and poor cognitive performance all found to be significantly associated with an increased risk of later schizophrenia. CONCLUSIONS Although some difficulties exist in analysing the interplay between each of these factors, the Swedish population registers have added considerably to our understanding of each of the presented individual aetiological themes. The ability to study the whole population over several decades has been particularly useful in determining the timing of exposures.
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Psychopathology in Substance Use Disorder Patients with and without Substance-Induced Psychosis. JOURNAL OF ADDICTION 2015; 2015:843762. [PMID: 26417473 PMCID: PMC4568375 DOI: 10.1155/2015/843762] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 07/23/2015] [Accepted: 08/23/2015] [Indexed: 12/23/2022]
Abstract
Background. Substance-induced psychotic disorder (SIPD) is a diagnosis constructed to distinguish substance-induced psychotic states from primary psychotic disorders. A number of studies have compared SIPD persons with primary psychotic patients, but there is little data on what differentiates substance use disorder (SUD) individuals with and without SIPD. Here, we compared psychopathology, sociodemographic variables, and substance use characteristics between SUD patients with and without SIPD. Methods. A retrospective chart review was conducted on newly admitted patients at a rehabilitation centre between 2007 and 2012. Results. Of the 379 patients included in the study, 5% were diagnosed with SIPD (n = 19) and 95% were diagnosed with SUDs without SIPD (n = 360). More SIPD patients reported using cannabis and psychostimulants, and fewer SIPD patients reported using alcohol than SUDs patients without SIPD. SIPD patients scored higher on the “schizophrenia nuclear symptoms” dimension of the SCL-90R psychoticism scale and exhibited more ClusterB personality traits than SUD patients without SIPD. Discussion. These data are consistent with previous studies suggesting that psychopathology, substance type, and sociodemographic variables play important role in the development of SIPD. More importantly, the results highlight the need for paying greater attention to the types of self-reported psychotic symptoms during the assessment of psychotomimetic effects associated with psychoactive substances.
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Day NL, Goldschmidt L, Day R, Larkby C, Richardson GA. Prenatal marijuana exposure, age of marijuana initiation, and the development of psychotic symptoms in young adults. Psychol Med 2015; 45:1779-87. [PMID: 25534593 PMCID: PMC8128137 DOI: 10.1017/s0033291714002906] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
BACKGROUND Studies have demonstrated that an early age of onset of marijuana use (EAOM) is associated with a higher risk of developing psychotic symptoms (PS) compared to initiating marijuana use at a later age or not at all. Research has also found that prenatal marijuana exposure (PME) predicts EAOM. This report evaluates the relationships among PME, EAOM, and PS. METHOD Subjects were initially interviewed in their fourth prenatal month. Women and offspring who completed the birth assessment (n = 763) were selected for follow-up. Women and their offspring were followed until the offspring were 22 years of age: 596 offspring were evaluated. At age 22, PS were assessed in the offspring with the Diagnostic Interview Schedule using DSM-IV criteria. Analyses controlled for significant covariates including other prenatal substance exposures, race, gender, and offspring substance use at 22 years. RESULTS PME and EAOM significantly predicted increased rates of PS at 22 years controlling for other significant covariates. The direct effect of PME on PS was marginally significant (p = 0.06) when EAOM was entered into the model and other covariates were fixed. In the mediation analysis, EAOM did not significantly mediate the association between PME and PS, controlling for significant covariates, nor was the indirect pathway significant when structural equation modeling was used. The total effect of the direct and indirect pathways was significant. CONCLUSIONS In addition to EAOM, PME may also play a role in the association between marijuana use and the development of PS. This could highlight a new area for prevention.
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Affiliation(s)
- N. L. Day
- Department of Psychiatry, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
| | - L. Goldschmidt
- University of Pittsburgh Medical Center, Pittsburgh, PA, USA
| | - R. Day
- Department of Biostatistics, University of Pittsburgh Graduate School of Public Health, Pittsburgh, PA, USA
| | - C. Larkby
- Department of Psychiatry, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
| | - G. A. Richardson
- Department of Psychiatry, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
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