1
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Schüler M, Moritz S, Schnell T. Development and initial validation of a reliable German self-report measure to assess acute cannabis intoxication-effects (CanTox-17). Int J Methods Psychiatr Res 2022; 31:e1925. [PMID: 35708959 PMCID: PMC9464325 DOI: 10.1002/mpr.1925] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/06/2021] [Revised: 01/30/2022] [Accepted: 05/27/2022] [Indexed: 11/19/2022] Open
Abstract
OBJECTIVES Both positive and negative including psychotic-like cannabis intoxication effects are well-established. Yet, consequences for consumption patterns, addictive behavior or psychotic developments are poorly researched in general, in Germany not at all. Thus, objective was to develop the first German-language questionnaire operationalizing acute cannabis intoxication effects, based on the original "Cannabis Experience Questionnaire" (CEQ). METHODS After expert translation of the CEQ, items related to acute intoxication effects were presented to a sample of 537 cannabis users. Four- and five-factorial solutions of explorative factor analysis with a randomly split sub-sample 1 were cross-validated by confirmatory factor analysis on sub-sample 2. RESULTS After content review of factors and analysis of external validity, a 17 item four-factorial model was approved. Factors are (1) "paranoia/dysphoria", (2) "confusion/disorientation", (3) "euphoria/creativity", (4) "psychosis-like/loss of reality". Model fit is satisfactory (RMSEA = 0.058, SRMR = 0.065, CFI = 0.929, TLI = 0.914). Correlations with corresponding external measures support construct validity. CONCLUSIONS The present questionnaire is a time-efficient, valid and reliable instrument. Thus, predictors of different cannabis intoxication effects can be analysed for the first time in German-speaking area, as well as their significance for substance use or psychosis risk.
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Affiliation(s)
- Merle Schüler
- Medical School Hamburg, University of Applied Sciences and Medical University, Hamburg, Germany
| | - Steffen Moritz
- Department of Psychiatry and Psychotherapy, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Thomas Schnell
- Medical School Hamburg, University of Applied Sciences and Medical University, Hamburg, Germany
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2
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Jang SK, Saunders G, Liu M, Jiang Y, Liu DJ, Vrieze S. Genetic correlation, pleiotropy, and causal associations between substance use and psychiatric disorder. Psychol Med 2022; 52:968-978. [PMID: 32762793 PMCID: PMC8759148 DOI: 10.1017/s003329172000272x] [Citation(s) in RCA: 36] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
BACKGROUND Substance use occurs at a high rate in persons with a psychiatric disorder. Genetically informative studies have the potential to elucidate the etiology of these phenomena. Recent developments in genome-wide association studies (GWAS) allow new avenues of investigation. METHOD Using results of GWAS meta-analyses, we performed a factor analysis of the genetic correlation structure, a genome-wide search of shared loci, and causally informative tests for six substance use phenotypes (four smoking, one alcohol, and one cannabis use) and five psychiatric disorders (ADHD, anorexia, depression, bipolar disorder, and schizophrenia). RESULTS Two correlated externalizing and internalizing/psychosis factor were found, although model fit was beneath conventional standards. Of 458 loci reported in previous univariate GWAS of substance use and psychiatric disorders, about 50% (230 loci) were pleiotropic with additional 111 pleiotropic loci not reported from past GWAS. Of the 341 pleiotropic loci, 152 were associated with both substance use and psychiatric disorders, implicating neurodevelopment, cell morphogenesis, biological adhesion pathways, and enrichment in 13 different brain tissues. Seventy-five and 114 pleiotropic loci were specific to either psychiatric disorders or substance use phenotypes, implicating neuronal signaling pathway and clathrin-binding functions/structures, respectively. No consistent evidence for phenotypic causation was found across different Mendelian randomization methods. CONCLUSIONS Genetic etiology of substance use and psychiatric disorders is highly pleiotropic and involves shared neurodevelopmental path, neurotransmission, and intracellular trafficking. In aggregate, the patterns are not consistent with vertical pleiotropy, more likely reflecting horizontal pleiotropy or more complex forms of phenotypic causation.
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Affiliation(s)
- Seon-Kyeong Jang
- Department of Psychology, University of Minnesota, Minneapolis, MN, USA
| | - Gretchen Saunders
- Department of Psychology, University of Minnesota, Minneapolis, MN, USA
| | - MengZhen Liu
- Department of Psychology, University of Minnesota, Minneapolis, MN, USA
| | | | - Yu Jiang
- Department of Public Health Sciences, Penn State College of Medicine, Hershey, PA, USA
- Institute of Personalized Medicine, Penn State College of Medicine, Hershey, PA, USA
| | - Dajiang J. Liu
- Department of Public Health Sciences, Penn State College of Medicine, Hershey, PA, USA
- Institute of Personalized Medicine, Penn State College of Medicine, Hershey, PA, USA
| | - Scott Vrieze
- Department of Psychology, University of Minnesota, Minneapolis, MN, USA
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Abstract
This article retraces the story of cannabis from the earliest contacts of humans
with the plant to its subsequent global expansion, its medicinal uses, and the discovery
of the endocannabinoid system in the 20th century. Cannabis was attested to around 12
000 years ago near the Altai Mountains in Central Asia, and since then, cannabis seeds
have accompanied the migration of nomadic peoples. Records of the medicinal use of
cannabis appear before the Common Era in China, Egypt, and Greece (Herodotus), and later
in the Roman empire (Pliny the Elder, Dioscorides, Galen). In the 19th century,
orientalists like Silvestre de Sacy, and Western physicians coming into contact with
Muslim and Indian cultures, like O’Shaughnessy and Moreau de Tours, introduced the
medicinal use of cannabis into Europe. The structure of the main psychoactive
phytocannabinoid, tetrahydrocannabinol (THC), was determined in Israel by Mechoulam and
Gaoni in 1964. This discovery opened the gate for many of the subsequent developments in
the field of endocannabinoid system (ECS) research. The advances in the scientific
knowledge of the ECS place the debate on cannabis liberalization in a new
context.
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Affiliation(s)
- Marc-Antoine Crocq
- Maison des Adolescents, Mulhouse, France; CAMUHA, University of Upper Alsace, Mulhouse, France
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4
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Sarris J, Sinclair J, Karamacoska D, Davidson M, Firth J. Medicinal cannabis for psychiatric disorders: a clinically-focused systematic review. BMC Psychiatry 2020; 20:24. [PMID: 31948424 PMCID: PMC6966847 DOI: 10.1186/s12888-019-2409-8] [Citation(s) in RCA: 109] [Impact Index Per Article: 27.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/22/2019] [Accepted: 12/15/2019] [Indexed: 12/14/2022] Open
Abstract
BACKGROUND Medicinal cannabis has received increased research attention over recent years due to loosening global regulatory changes. Medicinal cannabis has been reported to have potential efficacy in reducing pain, muscle spasticity, chemotherapy-induced nausea and vomiting, and intractable childhood epilepsy. Yet its potential application in the field of psychiatry is lesser known. METHODS The first clinically-focused systematic review on the emerging medical application of cannabis across all major psychiatric disorders was conducted. Current evidence regarding whole plant formulations and plant-derived cannabinoid isolates in mood, anxiety, sleep, psychotic disorders and attention deficit/hyperactivity disorder (ADHD) is discussed; while also detailing clinical prescription considerations (including pharmacogenomics), occupational and public health elements, and future research recommendations. The systematic review of the literature was conducted during 2019, assessing the data from all case studies and clinical trials involving medicinal cannabis or plant-derived isolates for all major psychiatric disorders (neurological conditions and pain were omitted). RESULTS The present evidence in the emerging field of cannabinoid therapeutics in psychiatry is nascent, and thereby it is currently premature to recommend cannabinoid-based interventions. Isolated positive studies have, however, revealed tentative support for cannabinoids (namely cannabidiol; CBD) for reducing social anxiety; with mixed (mainly positive) evidence for adjunctive use in schizophrenia. Case studies suggest that medicinal cannabis may be beneficial for improving sleep and post-traumatic stress disorder, however evidence is currently weak. Preliminary research findings indicate no benefit for depression from high delta-9 tetrahydrocannabinol (THC) therapeutics, or for CBD in mania. One isolated study indicates some potential efficacy for an oral cannabinoid/terpene combination in ADHD. Clinical prescriptive consideration involves caution in the use of high-THC formulations (avoidance in youth, and in people with anxiety or psychotic disorders), gradual titration, regular assessment, and caution in cardiovascular and respiratory disorders, pregnancy and breast-feeding. CONCLUSIONS There is currently encouraging, albeit embryonic, evidence for medicinal cannabis in the treatment of a range of psychiatric disorders. Supportive findings are emerging for some key isolates, however, clinicians need to be mindful of a range of prescriptive and occupational safety considerations, especially if initiating higher dose THC formulas.
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Affiliation(s)
- Jerome Sarris
- NICM Health Research Institute, Western Sydney University, Westmead, NSW, 2145, Australia.
- Department of Psychiatry, The Melbourne Clinic, Professorial Unit, The University of Melbourne, Melbourne, Australia.
| | - Justin Sinclair
- NICM Health Research Institute, Western Sydney University, Westmead, NSW, 2145, Australia
| | - Diana Karamacoska
- NICM Health Research Institute, Western Sydney University, Westmead, NSW, 2145, Australia
| | - Maggie Davidson
- NICM Health Research Institute, Western Sydney University, Westmead, NSW, 2145, Australia
| | - Joseph Firth
- NICM Health Research Institute, Western Sydney University, Westmead, NSW, 2145, Australia
- Division of Psychology and Mental Health, University of Manchester, Manchester, UK
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5
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Ortiz-Medina MB, Perea M, Torales J, Ventriglio A, Vitrani G, Aguilar L, Roncero C. Cannabis consumption and psychosis or schizophrenia development. Int J Soc Psychiatry 2018; 64:690-704. [PMID: 30442059 DOI: 10.1177/0020764018801690] [Citation(s) in RCA: 42] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
OBJECTIVE: Cannabis consumption produces psychopathology, in some cases psychotic episodes, which are of our interest in this work. However, the relationship between cannabis use and psychosis has not been fully elucidated. The objectives of this work are to (1) review the current state of knowledge on the association of cannabis use with the risk of the development of psychosis or psychotic symptoms in people without schizophrenia and (2) assess the consistency of the hypothesis that cannabis use is associated with increased risk of psychosis in people without schizophrenia. METHOD: This work included research done in humans until May 2018 with the keywords 'cannabis' and 'psychosis', published in English and Spanish, in the PubMed database. RESULTS: In all, 66 papers were analyzed, of which 23 were cohort trials and 43 were reviews. CONCLUSION: Cannabis use doubles the risk of developing psychosis in vulnerable people. There even exists a relationship regarding the dose used and the age of first use. Gene-environment interactions that modulate the association between cannabis use and the presence of psychosis have also been described.
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Affiliation(s)
- María Bettina Ortiz-Medina
- 1 Area of Research, Department of Medical Psychology, Faculty of Medical Sciences, National University Asuncion, San Lorenzo, Paraguay.,2 Hospital de Clínicas, Faculty of Medical Sciences, National University of Asuncion, San Lorenzo, Paraguay
| | - Marta Perea
- 3 Addiction and Dual Diagnosis Unit, Department of Psychiatry, Vall d'Hebron University Hospital, Public Health Agency of Barcelona (ASPB), CIBERSAM, Barcelona, Spain.,4 Department of Psychiatry and Legal Medicine, Autonomous University of Barcelona, Bellaterra, Spain
| | - Julio Torales
- 2 Hospital de Clínicas, Faculty of Medical Sciences, National University of Asuncion, San Lorenzo, Paraguay.,5 Department of Psychiatry, Faculty of Medical Sciences, National University of Asuncion, San Lorenzo, Paraguay
| | - Antonio Ventriglio
- 6 Department of Clinical and Experimental Medicine, University of Foggia, Foggia, Italy
| | - Giovanna Vitrani
- 6 Department of Clinical and Experimental Medicine, University of Foggia, Foggia, Italy
| | - Lourdes Aguilar
- 7 Psychiatric Service, University of Salamanca Health Care Complex, Salamanca, Spain.,8 Institute of Biomedicine of Salamanca, University of Salamanca, Salamanca, Spain
| | - Carlos Roncero
- 3 Addiction and Dual Diagnosis Unit, Department of Psychiatry, Vall d'Hebron University Hospital, Public Health Agency of Barcelona (ASPB), CIBERSAM, Barcelona, Spain.,7 Psychiatric Service, University of Salamanca Health Care Complex, Salamanca, Spain.,8 Institute of Biomedicine of Salamanca, University of Salamanca, Salamanca, Spain
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Independent associations and effect modification between lifetime substance use and recent mood disorder diagnosis with household food insecurity. PLoS One 2018; 13:e0191072. [PMID: 29360862 PMCID: PMC5779657 DOI: 10.1371/journal.pone.0191072] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2017] [Accepted: 12/26/2017] [Indexed: 11/25/2022] Open
Abstract
Poor mental health and substance use are associated with food insecurity, however, their potential combined effects have not been studied. This study explored independent associations and effect modification between lifetime substance use and mood disorder in relation to food insecurity. Poisson regression analysis of data from British Columbia respondents (n = 13,450; 12 years+) in the 2007/08 Canadian Community Health Survey was conducted. Measures included The Household Food Security Survey Module (7.3% food insecure), recent diagnosis of a mood disorder (self-reported; 9.5%), lifetime use of cannabis, cocaine/crack, ecstasy, hallucinogens, and speed, any lifetime substance use, sociodemographic covariates, and the interaction terms of mood disorder by substance. For those with recent diagnosis of a mood disorder the prevalence of lifetime substance use ranged between 1.2 to 5.7% and were significantly higher than those without recent mood disorder diagnosis or lifetime use of substances (p’s < 0.05). For respondents with a recent mood disorder diagnosis or who used cannabis, food insecurity prevalence was higher compared to the general sample (p < 0.001); prevalence was lower for cocaine/crack use (p < 0.05). Significant effect modification was found between mood disorder with cannabis, ecstasy, hallucinogen and any substance use over the lifetime (PRs 0.51 to 0.64, p’s 0.022 to 0.001). Independent associations were found for cocaine/crack and speed use (PRs 1.68, p’s < 0.001) and mood disorder (PRs 2.02, p’s < 0.001). Based on these findings and the existing literature, future study about coping and resilience in the context of substance use, mental health, and food insecurity may lead to the development of relevant interventions aimed at mental well-being and food security.
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Cannabis and Amphetamine-type Stimulant-induced Psychoses: A Systematic Overview. ADDICTIVE DISORDERS & THEIR TREATMENT 2016. [DOI: 10.1097/adt.0000000000000086] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Richardson KA, Hester AK, McLemore GL. Prenatal cannabis exposure - The "first hit" to the endocannabinoid system. Neurotoxicol Teratol 2016; 58:5-14. [PMID: 27567698 DOI: 10.1016/j.ntt.2016.08.003] [Citation(s) in RCA: 79] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2016] [Revised: 07/25/2016] [Accepted: 08/19/2016] [Indexed: 12/18/2022]
Abstract
As more states and countries legalize medical and/or adult recreational marijuana use, the incidences of prenatal cannabis exposure (PCE) will likely increase. While young people increasingly view marijuana as innocuous, marijuana preparations have been growing in potency in recent years, potentially creating global clinical, public health, and workforce concerns. Unlike fetal alcohol spectrum disorder, there is no phenotypic syndrome associated with PCE. There is also no preponderance of evidence that PCE causes lifelong cognitive, behavioral, or functional abnormalities, and/or susceptibility to subsequent addiction. However, there is compelling circumstantial evidence, based on the principles of teratology and fetal malprogramming, suggesting that pregnant women should refrain from smoking marijuana. The usage of marijuana during pregnancy perturbs the fetal endogenous cannabinoid signaling system (ECSS), which is present and active from the early embryonic stage, modulating neurodevelopment and continuing this role into adulthood. The ECSS is present in virtually every brain structure and organ system, and there is also evidence that this system is important in the regulation of cardiovascular processes. Endocannabinoids (eCBs) undergird a broad spectrum of processes, including the early stages of fetal neurodevelopment and uterine implantation. Delta-9-tetrahydrocannabinol (THC), the psychoactive chemical in cannabis, enters maternal circulation, and readily crosses the placental membrane. THC binds to CB receptors of the fetal ECSS, altering neurodevelopment and possibly rewiring ECSS circuitry. In this review, we discuss the Double-Hit Hypothesis as it relates to PCE. We contend that PCE, similar to a neurodevelopmental teratogen, delivers the first hit to the ECSS, which is compromised in such a way that a second hit (i.e., postnatal stressors) will precipitate the emergence of a specific phenotype. In summary, we conclude that perturbations of the intrauterine milieu via the introduction of exogenous CBs alter the fetal ECSS, predisposing the offspring to abnormalities in cognition and altered emotionality. Based on recent experimental evidence that we will review here, we argue that young women who become pregnant should immediately take a "pregnant pause" from using marijuana.
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Affiliation(s)
- Kimberlei A Richardson
- Howard University College of Medicine, Department of Pharmacology, 520 W Street, NW, Suite 3408, Washington, DC 20059, United States.
| | - Allison K Hester
- Howard University College of Medicine, Department of Pharmacology, 520 W Street, NW, Suite 3408, Washington, DC 20059, United States.
| | - Gabrielle L McLemore
- Morgan State University, Department of Biology-SCMMS, 1700 East Cold Spring Lane, Baltimore, MD 21251, United States.
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9
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Feingold D, Weiser M, Rehm J, Lev-Ran S. The association between cannabis use and mood disorders: A longitudinal study. J Affect Disord 2015; 172:211-8. [PMID: 25451420 DOI: 10.1016/j.jad.2014.10.006] [Citation(s) in RCA: 109] [Impact Index Per Article: 12.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/19/2014] [Revised: 10/03/2014] [Accepted: 10/04/2014] [Indexed: 01/21/2023]
Abstract
BACKGROUND The association between cannabis use and mood disorders is well documented, yet evidence regarding causality is conflicting. This study explored the association between cannabis use, major depressive disorder (MDD) and bipolar disorder (BPD) in a 3-year prospective study. METHODS Data was drawn from waves 1 and 2 of the National Epidemiologic Survey on Alcohol and Related Conditions (NESARC). MDD and BPD were controlled at baseline and defined as meeting full criteria in the 12 months prior to the follow-up. Initiation of cannabis use was defined as any cannabis used by former lifetime abstainers in the time period between baseline and follow-up. RESULTS Cannabis use was not significantly associated with increased incidence of MDD (Adjusted Odds Ratio (AOR) for daily use=0.58(0.22-1.51)). Weekly to almost daily cannabis use was associated with increased incidence of BPD ((AOR for weekly to daily use=2.47(1.03-5.92)); daily use was not (AOR=0.52(0.17-1.55)). Baseline MDD was associated with initiation of cannabis use (AOR=1.72(1.1-2.69)). A crude association between baseline BPD and incidence of cannabis use was not maintained in adjusted models (AOR=0.61(0.36-1.04)). LIMITATIONS Lack of information regarding frequency of cannabis use at follow-up and limitations regarding generalization of the results. CONCLUSIONS Our findings do not support a longitudinal association between cannabis use and incidence of MDD. Results regarding the association between cannabis use and incidence of BPD are conflicting and require further investigation. Baseline MDD, but not BPD, may be associated with future initiation of cannabis use. This may have implications for clinical, social and legislative aspects of cannabis use.
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Affiliation(s)
- Daniel Feingold
- Ariel University, Israel; Addiction Medicine Services, Department of Psychiatry, Sheba Medical Center, Tel Hashomer, Israel.
| | - Mark Weiser
- Department of Psychiatry, Sheba Medical Center, Tel Hashomer, Israel; Sackler Faculty of Medicine, Tel Aviv University, Israel
| | - Jürgen Rehm
- Social and Epidemiological Research Department, Centre for Addiction and Mental Health, Toronto, Ontario, Canada; Dalla Lana School of Public Health, University of Toronto, Toronto, Ontario, Canada
| | - Shaul Lev-Ran
- Addiction Medicine Services, Department of Psychiatry, Sheba Medical Center, Tel Hashomer, Israel; Sackler Faculty of Medicine, Tel Aviv University, Israel; Social and Epidemiological Research Department, Centre for Addiction and Mental Health, Toronto, Ontario, Canada
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10
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Calvigioni D, Hurd YL, Harkany T, Keimpema E. Neuronal substrates and functional consequences of prenatal cannabis exposure. Eur Child Adolesc Psychiatry 2014; 23:931-41. [PMID: 24793873 PMCID: PMC4459494 DOI: 10.1007/s00787-014-0550-y] [Citation(s) in RCA: 84] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/30/2014] [Accepted: 04/15/2014] [Indexed: 02/01/2023]
Abstract
Cannabis remains one of the world's most widely used substance of abuse amongst pregnant women. Trends of the last 50 years show an increase in popularity in child-bearing women together with a constant increase in cannabis potency. In addition, potent herbal "legal" highs containing synthetic cannabinoids that mimic the effects of cannabis with unknown pharmacological and toxicological effects have gained rapid popularity amongst young adults. Despite the surge in cannabis use during pregnancy, little is known about the neurobiological and psychological consequences in the exposed offspring. In this review, we emphasize the importance of maternal programming, defined as the intrauterine presentation of maternal stimuli to the foetus, in neurodevelopment. In particular, we focus on cannabis-mediated maternal adverse effects, resulting in direct central nervous system alteration or sensitization to late-onset chronic and neuropsychiatric disorders. We compare clinical and preclinical experimental studies on the effects of foetal cannabis exposure until early adulthood, to stress the importance of animal models that permit the fine control of environmental variables and allow the dissection of cannabis-mediated molecular cascades in the developing central nervous system. In sum, we conclude that preclinical experimental models confirm clinical studies and that cannabis exposure evokes significant molecular modifications to neurodevelopmental programs leading to neurophysiological and behavioural abnormalities.
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Affiliation(s)
- Daniela Calvigioni
- Division of Molecular Neurobiology, Department of Medical Biochemistry and Biophysics, Karolinska Institutet, 17177 Stockholm, Sweden. Department of Molecular Neurosciences, Center for Brain Research, Medical University of Vienna, 1090 Vienna, Austria
| | - Yasmin L. Hurd
- Department of Psychiatry and Pharmacology and Systems Therapeutics, Icahn School of Medicine at Mount Sinai, New York, NY 10029-6574, USA
| | - Tibor Harkany
- Division of Molecular Neurobiology, Department of Medical Biochemistry and Biophysics, Karolinska Institutet, 17177 Stockholm, Sweden. Department of Molecular Neurosciences, Center for Brain Research, Medical University of Vienna, 1090 Vienna, Austria
| | - Erik Keimpema
- Department of Molecular Neurosciences, Center for Brain Research, Medical University of Vienna, 1090 Vienna, Austria
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Greenwood LM, Broyd SJ, Croft R, Todd J, Michie PT, Johnstone S, Murray R, Solowij N. Chronic effects of cannabis use on the auditory mismatch negativity. Biol Psychiatry 2014; 75:449-58. [PMID: 23830666 DOI: 10.1016/j.biopsych.2013.05.035] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/11/2012] [Revised: 05/26/2013] [Accepted: 05/30/2013] [Indexed: 01/01/2023]
Abstract
BACKGROUND Cannabis use is associated with the development of psychotic symptoms and increased risk for schizophrenia. The mismatch negativity (MMN) is a brain event-related potential marker of change detection thought to index glutamatergic N-methyl-D-aspartate receptor-mediated neurotransmission, which is known to be deficient in schizophrenia. This study examined auditory MMN in otherwise healthy chronic cannabis users compared with nonuser control subjects. METHODS Forty-two chronic cannabis users and 44 nonuser healthy control subjects completed a multi-feature MMN paradigm, which included duration, frequency, and intensity deviants (deviants 6%; standards 82%). The MMN was compared between users and control subjects as well as between long- and short-term users and age- and gender-matched control subjects. Associations between MMN, cannabis use measures, and symptoms were examined. RESULTS The MMN amplitude was significantly reduced to frequency but not duration or intensity deviants in overall cannabis users relative to control subjects. Frequency MMN was similarly attenuated in short- and long-term users relative to control subjects. Long-term users also exhibited reduced duration MMN relative to control subjects and short-term users and this was correlated with increased duration of exposure to cannabis and increased psychotic-like experiences during intoxication. In short-term users, a younger age of onset of regular cannabis use and greater frequency of use were associated with greater psychotic-like experiences and symptomatic distress. CONCLUSIONS These results suggest impaired sensory memory that might reflect N-methyl-D-aspartate receptor dysfunction in chronic cannabis users. The pattern of MMN alterations in cannabis users differed from that typically observed in patients with schizophrenia, indicating overlapping but distinct underlying pathology.
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Affiliation(s)
- Lisa-Marie Greenwood
- School of Psychology and ψ-P3: Centre for Psychophysics, Psychophysiology and Psychopharmacology, University of Wollongong, Wollongong
| | - Samantha J Broyd
- School of Psychology and ψ-P3: Centre for Psychophysics, Psychophysiology and Psychopharmacology, University of Wollongong, Wollongong
| | - Rodney Croft
- School of Psychology and ψ-P3: Centre for Psychophysics, Psychophysiology and Psychopharmacology, University of Wollongong, Wollongong
| | - Juanita Todd
- School of Psychology and Priority Research Centre for Translational Neuroscience and Mental Health, University of Newcastle, Newcastle; Schizophrenia Research Institute, Sydney, New South Wales, Australia
| | - Patricia T Michie
- School of Psychology and Priority Research Centre for Translational Neuroscience and Mental Health, University of Newcastle, Newcastle; Schizophrenia Research Institute, Sydney, New South Wales, Australia
| | - Stuart Johnstone
- School of Psychology and ψ-P3: Centre for Psychophysics, Psychophysiology and Psychopharmacology, University of Wollongong, Wollongong
| | - Robin Murray
- Institute of Psychiatry, Kings College, London, United Kingdom
| | - Nadia Solowij
- School of Psychology and ψ-P3: Centre for Psychophysics, Psychophysiology and Psychopharmacology, University of Wollongong, Wollongong; Schizophrenia Research Institute, Sydney, New South Wales, Australia.
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12
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Mura G, Petretto DR, Bhat KM, Carta MG. Schizophrenia: from epidemiology to rehabilitation. Clin Pract Epidemiol Ment Health 2012; 8:52-66. [PMID: 22962559 PMCID: PMC3434422 DOI: 10.2174/1745017901208010052] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2011] [Revised: 12/26/2011] [Accepted: 01/01/2012] [Indexed: 12/27/2022]
Abstract
Purpose/Objective: We discuss recent evidences about schizophrenia (frequency, onset, course, risk factors and genetics) and their influences to some epidemiological myths about schizophrenia diffuse between psychiatric and psychopathology clinicians. The scope is to evaluate if the new acquisitions may change the rehabilitation approaches to schizophrenia modifying the balance about the neurodevelopmental hypothesis of schizophrenia accepting that the cognitive deficits are produced by errors during the normal development of the brain (neurodevelopmental hypothesis) that remains stable in the course of illness and the neurodegenerative hypothesis according of which they derived from a degenerative process that goes on inexorably. Research Method/Design: A review of the literature about epidemiology of schizophrenia has been performed and the contributions of some of these evidence to neurodevelopmental hypothesis and to rehabilitation has been described. Results: It cannot be definitively concluded for or against the neurodevelopmental or degenerative hypothesis, but efforts in understanding basis of schizophrenia must go on. Until now, rehabilitation programs are based on the vulnerability-stress model: supposing an early deficit that go on stable during the life under favorable circumstances. So, rehabilitation approaches (as neuro-cognitive approaches, social skill training, cognitive-emotional training) are focused on the individual and micro-group coping skills, aiming to help people with schizophrenia to cope with environmental stress factors. Conclusions/Implications: Coping of cognitive deficits in schizophrenia may represents the starting-point for further research on schizophrenia, cohort studies and randomized trials are necessary to defined the range of effectiveness and the outcome of the treatments.
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Affiliation(s)
- Gioia Mura
- Consultation Liaison Psychiatric Unit at the University Hospital of Cagliari, University of Cagliari and AOU Cagliari - Italy
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Avdesh A, Cornelisse V, Martin-Iverson MT. Corticosteroid dependent and independent effects of a cannabinoid agonist on core temperature, motor activity, and prepulse inhibition of the acoustic startle reflex in Wistar rats. Psychopharmacology (Berl) 2012; 220:405-15. [PMID: 21947354 DOI: 10.1007/s00213-011-2493-z] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/29/2011] [Accepted: 09/03/2011] [Indexed: 10/17/2022]
Abstract
RATIONALE There are inconsistent reports on the effects of cannabinoid agonists on prepulse inhibition of the startle reflex (PPI) with increases, decreases, and no effects. It has been hypothesized that the conflicting observations may be as a result of modulation of the effects of cannabinoid agonists by the regulation of corticosteroid release. OBJECTIVE The purpose of the present study was to determine the effects of CP55940, a cannabinoid agonist, and metyrapone, a corticosteroid synthesis inhibitor on core temperature, motor activity, the startle reflex, and PPI. METHODS Startle responses were measured in 64 male Wistar rats while varying startling stimulus intensities, analogous to dose-response curves. A stimulus potency measure (ES(50)) and a response measure, the maximal achievable response (R (MAX)) were derived from the stimulus-response curves. RESULTS CP55940 reduced core temperature and motor activity; these effects were potentiated by metyrapone. CP55940 increased R (MAX) of startle in the absence of a prepulse by a corticosteroid-dependent mechanism but decreased it when metyrapone was administered before CP55940, a corticosteroid-independent mechanism. The inverse of stimulus potency (ES(50)) was not affected by either drug alone but was increased by the combined drugs. CP55940 increased the prepulse motor gating effects and decreased the prepulse sensory gating effects of the same prepulses but only when given after metyrapone. CONCLUSIONS The most parsimonious interpretation of these effects is that CP55940 has some effects through corticosteroid-dependent actions and opposite effects by corticosteroid-independent actions. These two putative sites of actions affect stimulus gating opposite to their effects on response gating.
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Affiliation(s)
- Avdesh Avdesh
- Centre for Clinical Research in Neuropsychiatry, Graylands Hospital, The University of Western Australia, Perth, Western Australia, Australia
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Cadenhead KS. Startle reactivity and prepulse inhibition in prodromal and early psychosis: effects of age, antipsychotics, tobacco and cannabis in a vulnerable population. Psychiatry Res 2011; 188:208-16. [PMID: 21555157 PMCID: PMC3114288 DOI: 10.1016/j.psychres.2011.04.011] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/07/2010] [Revised: 03/22/2011] [Accepted: 04/12/2011] [Indexed: 10/18/2022]
Abstract
The use of biomarkers in the study of the prodrome and first episode of psychosis provides a means of not only identifying individuals at greatest risk for psychosis but also understanding neurodevelopmental abnormalities early in the course of illness. Prepulse inhibition (PPI), a marker that is deficient in schizophrenia and after developmental manipulations in animal models, was assessed in 75 early psychosis (EP), 89 at risk (AR) for psychosis and 85 comparison subjects (CS) at baseline and 6 months. Consistent with findings in chronic schizophrenia, PPI was stable with repeated assessment and EP subjects had reduced PPI but this was most evident in tobacco smokers. A significant positive PPI and age association in AR and EP samples, but not CS, demonstrated potential neurodevelopmental differences in early psychosis. Unexpected findings included the fact that medication naive EP subjects, as well as AR subjects who later developed psychosis, had greater PPI, introducing the possibility of early compensatory changes that diverge from findings in chronic patients. In addition, subjects with a history of cannabis use had greater startle reactivity while EP and AR subjects who used cannabis and were also taking an antipsychotic had greater PPI, again highlighting the potentially important cannabis/psychosis association.
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15
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Need AC, Ge D, Weale ME, Maia J, Feng S, Heinzen EL, Shianna KV, Yoon W, Kasperavičiūtė D, Gennarelli M, Strittmatter WJ, Bonvicini C, Rossi G, Jayathilake K, Cola PA, McEvoy JP, Keefe RSE, Fisher EMC, St. Jean PL, Giegling I, Hartmann AM, Möller HJ, Ruppert A, Fraser G, Crombie C, Middleton LT, St. Clair D, Roses AD, Muglia P, Francks C, Rujescu D, Meltzer HY, Goldstein DB. A genome-wide investigation of SNPs and CNVs in schizophrenia. PLoS Genet 2009; 5:e1000373. [PMID: 19197363 PMCID: PMC2631150 DOI: 10.1371/journal.pgen.1000373] [Citation(s) in RCA: 361] [Impact Index Per Article: 24.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2008] [Accepted: 01/07/2009] [Indexed: 12/13/2022] Open
Abstract
We report a genome-wide assessment of single nucleotide polymorphisms (SNPs) and copy number variants (CNVs) in schizophrenia. We investigated SNPs using 871 patients and 863 controls, following up the top hits in four independent cohorts comprising 1,460 patients and 12,995 controls, all of European origin. We found no genome-wide significant associations, nor could we provide support for any previously reported candidate gene or genome-wide associations. We went on to examine CNVs using a subset of 1,013 cases and 1,084 controls of European ancestry, and a further set of 60 cases and 64 controls of African ancestry. We found that eight cases and zero controls carried deletions greater than 2 Mb, of which two, at 8p22 and 16p13.11-p12.4, are newly reported here. A further evaluation of 1,378 controls identified no deletions greater than 2 Mb, suggesting a high prior probability of disease involvement when such deletions are observed in cases. We also provide further evidence for some smaller, previously reported, schizophrenia-associated CNVs, such as those in NRXN1 and APBA2. We could not provide strong support for the hypothesis that schizophrenia patients have a significantly greater "load" of large (>100 kb), rare CNVs, nor could we find common CNVs that associate with schizophrenia. Finally, we did not provide support for the suggestion that schizophrenia-associated CNVs may preferentially disrupt genes in neurodevelopmental pathways. Collectively, these analyses provide the first integrated study of SNPs and CNVs in schizophrenia and support the emerging view that rare deleterious variants may be more important in schizophrenia predisposition than common polymorphisms. While our analyses do not suggest that implicated CNVs impinge on particular key pathways, we do support the contribution of specific genomic regions in schizophrenia, presumably due to recurrent mutation. On balance, these data suggest that very few schizophrenia patients share identical genomic causation, potentially complicating efforts to personalize treatment regimens.
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Affiliation(s)
- Anna C. Need
- Institute for Genome Sciences and Policy, Duke University, Durham, North Carolina, United States of America
| | - Dongliang Ge
- Institute for Genome Sciences and Policy, Duke University, Durham, North Carolina, United States of America
| | - Michael E. Weale
- Department of Medical and Molecular Genetics, King's College London, Guy's Hospital, London, United Kingdom
| | - Jessica Maia
- Institute for Genome Sciences and Policy, Duke University, Durham, North Carolina, United States of America
| | - Sheng Feng
- Department of Biostatistics and Bioinformatics, Duke University, Durham, North Carolina, United States of America
| | - Erin L. Heinzen
- Institute for Genome Sciences and Policy, Duke University, Durham, North Carolina, United States of America
| | - Kevin V. Shianna
- Institute for Genome Sciences and Policy, Duke University, Durham, North Carolina, United States of America
| | - Woohyun Yoon
- Institute for Genome Sciences and Policy, Duke University, Durham, North Carolina, United States of America
| | | | - Massimo Gennarelli
- Genetic Unit, IRCCS San Giovanni di Dio Fatebenefratelli, Brescia, Italy
- Department of Biomedical Science and Biotech, University of Brescia, Brescia, Italy
| | - Warren J. Strittmatter
- Division of Neurology, Department of Medicine, Duke University Medical Center, Durham, North Carolina, United States of America
| | - Cristian Bonvicini
- Genetic Unit, IRCCS San Giovanni di Dio Fatebenefratelli, Brescia, Italy
| | - Giuseppe Rossi
- Psychiatric Unit, IRCCS San Giovanni di Dio Fatebenefratelli, Brescia, Italy
| | - Karu Jayathilake
- Department of Psychiatry, Vanderbilt University School of Medicine, Nashville, Tennessee, United States of America
| | - Philip A. Cola
- University Hospitals Case Medical Center, Cleveland, Ohio, United States of America
| | - Joseph P. McEvoy
- Department of Psychiatry and Behavioral Sciences, Duke University Medical Center, Durham, North Carolina, United States of America
| | - Richard S. E. Keefe
- Department of Psychiatry and Behavioral Sciences, Duke University Medical Center, Durham, North Carolina, United States of America
| | | | - Pamela L. St. Jean
- Genetics Division, GlaxoSmithKline, Research Triangle Park, North Carolina, United States of America
| | - Ina Giegling
- Division of Molecular and Clinical Neurobiology, Department of Psychiatry, Ludwig-Maximilians-University, Munich, Germany
| | - Annette M. Hartmann
- Division of Molecular and Clinical Neurobiology, Department of Psychiatry, Ludwig-Maximilians-University, Munich, Germany
| | - Hans-Jürgen Möller
- Department of Psychiatry, Ludwig-Maximilians-University, Munich, Germany
| | | | - Gillian Fraser
- Department of Mental Health, University of Aberdeen, Aberdeen, United Kingdom
| | - Caroline Crombie
- Department of Mental Health, University of Aberdeen, Aberdeen, United Kingdom
| | - Lefkos T. Middleton
- Division of Neuroscience and Mental Health, Neuroscience Laboratories, Burlington Danes, Hammersmith Hospital, London, United Kingdom
| | - David St. Clair
- Department of Mental Health, University of Aberdeen, Aberdeen, United Kingdom
| | - Allen D. Roses
- Deane Drug Discovery Institute, Duke University Medical Center, Durham, North Carolina, United States of America
| | | | - Clyde Francks
- Medical Genetics, GlaxoSmithKline R&D, Verona, Italy
| | - Dan Rujescu
- Division of Molecular and Clinical Neurobiology, Department of Psychiatry, Ludwig-Maximilians-University, Munich, Germany
| | - Herbert Y. Meltzer
- Department of Psychiatry, Vanderbilt University School of Medicine, Nashville, Tennessee, United States of America
| | - David B. Goldstein
- Institute for Genome Sciences and Policy, Duke University, Durham, North Carolina, United States of America
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16
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D’Souza DC, Ranganathan M, Braley G, Gueorguieva R, Zimolo Z, Cooper T, Perry E, Krystal J. Blunted psychotomimetic and amnestic effects of delta-9-tetrahydrocannabinol in frequent users of cannabis. Neuropsychopharmacology 2008; 33:2505-16. [PMID: 18185500 PMCID: PMC3799954 DOI: 10.1038/sj.npp.1301643] [Citation(s) in RCA: 189] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Cannabis is one of the most widely used illicit substances and there is growing interest in the association between cannabis use and psychosis. Delta-9-Tetrahydrocannabinol (Delta-9-THC) the principal active ingredient of cannabis has been shown to induce psychotomimetic and amnestic effects in healthy individuals. Whether people who frequently use cannabis are either protected from or are tolerant to these effects of Delta-9-THC has not been established. In a 3-day, double-blind, randomized, placebo-controlled study, the dose-related effects of 0, 2.5, and 5 mg intravenous Delta-9-THC were studied in 30 frequent users of cannabis and compared to 22 healthy controls. Delta-9-THC (1) produced transient psychotomimetic effects and perceptual alterations; (2) impaired memory and attention; (3) increased subjective effects of 'high'; (4) produced tachycardia; and (5) increased serum cortisol in both groups. However, relative to controls, frequent users showed blunted responses to the psychotomimetic, perceptual altering, cognitive impairing, anxiogenic, and cortisol increasing effects of Delta-9-THC but not to its euphoric effects. Frequent users also had lower prolactin levels. These data suggest that frequent users of cannabis are either inherently blunted in their response to, and/or develop tolerance to the psychotomimetic, perceptual altering, amnestic, endocrine, and other effects of cannabinoids.
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Affiliation(s)
- Deepak Cyril D’Souza
- Schizophrenia Biological Research Center, VA Connecticut Healthcare System, West Haven, CT
,Abraham Ribicoff Research Facilities, Connecticut Mental Health Center, New Haven, CT
,Department of Psychiatry, Yale University School of Medicine, New Haven, CT
| | - Mohini Ranganathan
- Schizophrenia Biological Research Center, VA Connecticut Healthcare System, West Haven, CT
,Department of Psychiatry, Yale University School of Medicine, New Haven, CT
| | - Gabriel Braley
- Schizophrenia Biological Research Center, VA Connecticut Healthcare System, West Haven, CT
,Department of Psychiatry, Yale University School of Medicine, New Haven, CT
| | - Ralitza Gueorguieva
- Abraham Ribicoff Research Facilities, Connecticut Mental Health Center, New Haven, CT
,Division of Biostatistics, Department of Epidemiology and Public Health, Yale University, New Haven CT
| | - Zoran Zimolo
- Schizophrenia Biological Research Center, VA Connecticut Healthcare System, West Haven, CT
,Department of Psychiatry, Yale University School of Medicine, New Haven, CT
| | - Thomas Cooper
- Department of Psychiatry, Columbia University, College of Physicians and Surgeons, New York, New York and the Nathan Kline Institute, Orangeburg New York
| | - Edward Perry
- Schizophrenia Biological Research Center, VA Connecticut Healthcare System, West Haven, CT
,Department of Psychiatry, Yale University School of Medicine, New Haven, CT
| | - John Krystal
- Schizophrenia Biological Research Center, VA Connecticut Healthcare System, West Haven, CT
,Abraham Ribicoff Research Facilities, Connecticut Mental Health Center, New Haven, CT
,Department of Psychiatry, Yale University School of Medicine, New Haven, CT
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17
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Harkany T, Keimpema E, Barabás K, Mulder J. Endocannabinoid functions controlling neuronal specification during brain development. Mol Cell Endocrinol 2008; 286:S84-90. [PMID: 18394789 DOI: 10.1016/j.mce.2008.02.011] [Citation(s) in RCA: 131] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/21/2007] [Revised: 02/19/2008] [Accepted: 02/19/2008] [Indexed: 01/30/2023]
Abstract
Endocannabinoids (eCBs) regulate a broad range of physiological functions in the postnatal brain and are implicated in the neuropathogenesis of psychiatric and metabolic diseases. Accumulating evidence indicates that eCB signaling also serves key functions during neurodevelopment; and is inherently involved in the control of neurogenesis, neural progenitor proliferation, lineage segregation, and the migration and phenotypic specification of immature neurons. Recent advances in developmental biology define fundamental eCB-driven cellular mechanisms that also contribute to our understanding of the molecular substrates of prenatal drug, in particular cannabis, actions. Here, we summarize known organizing principles of eCB-signaling systems in the developing telencephalon, and outline the sequence of decision points and underlying signaling pathways upon CB1 cannabinoid receptor activation that contribute to neuronal diversification in the developing brain. Finally, we discuss how these novel principles affect the formation of complex neuronal networks.
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Affiliation(s)
- Tibor Harkany
- Institute of Medical Sciences, School of Medical Sciences, University of Aberdeen, Aberdeen AB25 2ZD, Scotland, United Kingdom.
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18
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Abstract
The acute side effects caused by cannabis use are mainly related to psyche and cognition, and to circulation. Euphoria, anxiety, changes in sensory perception, impairment of memory and psychomotor performance are common effects after a dose is taken that exceeds an individually variable threshold. Cannabis consumption may increase heart rate and change blood pressure, which may have serious consequences in people with heart disease. Effects of chronic use may be induction of psychosis and development of dependency to the drug. Effects on cognitive abilities seem to be reversible after abstinence, except possibly in very heavy users. Cannabis exposure in utero may have negative consequences on brain development with subtle impairment of cognitive abilities in later life. Consequences of cannabis smoking may be similar to those of tobacco smoking and should be avoided. Use by young people has more detrimental effects than use by adults. There appear to be promising therapeutic uses of cannabis for a range of indications. Use of moderate doses in a therapeutic context is usually not associated with severe side effects. Current prohibition on cannabis use may also have harmful side effects for the individual and the society, while having little influence on prevalence of use. Harm is greatest for seriously ill people who may benefit from a treatment with cannabis. This makes it difficult to justify criminal penalties against patients.
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19
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Van Laere K. In vivo imaging of the endocannabinoid system: a novel window to a central modulatory mechanism in humans. Eur J Nucl Med Mol Imaging 2007; 34:1719-26. [PMID: 17643242 DOI: 10.1007/s00259-007-0505-3] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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20
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Chahl LA. TRP's: links to schizophrenia? Biochim Biophys Acta Mol Basis Dis 2007; 1772:968-77. [PMID: 17587552 DOI: 10.1016/j.bbadis.2007.05.003] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2007] [Revised: 05/15/2007] [Accepted: 05/15/2007] [Indexed: 01/22/2023]
Abstract
Schizophrenia is a chronic psychiatric disorder the cause of which is unknown. It is considered to be a neurodevelopmental disorder that results from an interaction of genetic and environmental factors. Direct evidence for links between schizophrenia and TRP channels is lacking. However, several aspects of the pathophysiology of the disorder point to a possible involvement of TRP channels. In this review evidence for links between TRP channels and schizophrenia with respect to neurodevelopment, dopaminergic and cannabinoid systems, thermoregulation, and sensory processes, is discussed. Investigation of these links holds the prospect of a new understanding of schizophrenia with resultant therapeutic advances.
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Affiliation(s)
- Loris A Chahl
- Centre for Mental Health Studies and Schizophrenia Research Institute, James Fletcher Hospital, University of Newcastle, New South Wales, 2308 Australia.
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21
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Gregg L, Barrowclough C, Haddock G. Reasons for increased substance use in psychosis. Clin Psychol Rev 2007; 27:494-510. [PMID: 17240501 DOI: 10.1016/j.cpr.2006.09.004] [Citation(s) in RCA: 138] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2006] [Accepted: 09/29/2006] [Indexed: 11/25/2022]
Abstract
Around half of all patients with schizophrenia are thought to abuse drugs or alcohol and there is good evidence to suggest that they have poorer outcomes than their non substance using counterparts. However, despite more than twenty years of research there is still no consensus on the aetiology of increased rates of substance use in people with psychosis. There is a clear need to understand the reasons for such high rates of substance use if treatments designed to help patients abstain from substance use are to be successful. This paper provides an update of the literature examining the reasons for substance use by people with psychosis, and includes a comprehensive review of the self report literature. The main theories as to why people with psychosis use substances are presented. There is evidence to suggest that cannabis may have a causal role in the development of psychopathology but not for other substances. The self report literature provides support for an 'alleviation of dysphoria' model of substance use but there is little empirical support for the self medication hypothesis, or for common factor models and bidirectional models of comorbidity. It is likely that there are multiple risk factors involved in substance use in psychosis and more work to develop and test multiple risk factor models is required.
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Affiliation(s)
- Lynsey Gregg
- Division of Clinical Psychology, School of Psychological Sciences, University of Manchester, Rutherford House, Manchester Science Park, Manchester, United Kingdom.
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22
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Elman I, Borsook D, Lukas SE. Food intake and reward mechanisms in patients with schizophrenia: implications for metabolic disturbances and treatment with second-generation antipsychotic agents. Neuropsychopharmacology 2006; 31:2091-120. [PMID: 16541087 DOI: 10.1038/sj.npp.1301051] [Citation(s) in RCA: 111] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
Obesity is highly prevalent among patients with schizophrenia and is associated with detrimental health consequences. Although excessive consumption of fast food and pharmacotherapy with such second-generation antipsychotic agents (SGAs) as clozapine and olanzapine has been implicated in the schizophrenia/obesity comorbidity, the pathophysiology of this link remains unclear. Here, we propose a mechanism based on brain reward function, a relevant etiologic factor in both schizophrenia and overeating. A comprehensive literature search on neurobiology of schizophrenia and of eating behavior was performed. The collected articles were critically reviewed and relevant data were extracted and summarized within four key areas: (1) energy homeostasis, (2) food reward and hedonics, (3) reward function in schizophrenia, and (4) metabolic effects of the SGAs. A mesolimbic hyperdopaminergic state may render motivational/incentive reward system insensitive to low salience/palatability food. This, together with poor cognitive control from hypofunctional prefrontal cortex and enhanced hedonic impact of food, owing to exaggerated opioidergic drive (clinically manifested as pain insensitivity), may underlie unhealthy eating habits in patients with schizophrenia. Treatment with SGAs purportedly improves dopamine-mediated reward aspects, but at the cost of increased appetite and worsened or at least not improved opiodergic capacity. These effects can further deteriorate eating patterns. Pathophysiological and therapeutic implications of these insights need further validation via prospective clinical trials and neuroimaging studies.
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Affiliation(s)
- Igor Elman
- Behavioral Psychopharmacology Research Laboratory, Department of Psychiatry, McLean Hospital and Harvard Medical School, Belmont, MA 02478, USA.
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23
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Hall W, Degenhardt L. What are the policy implications of the evidence on cannabis and psychosis? CANADIAN JOURNAL OF PSYCHIATRY. REVUE CANADIENNE DE PSYCHIATRIE 2006; 51:566-74. [PMID: 17007223 DOI: 10.1177/070674370605100904] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
OBJECTIVE To explore the implications for mental health services, for health education about the risks of cannabis use, and for public policy toward cannabis use of observational evidence that cannabis use is a contributory cause of psychosis. METHOD Using comparative analyses of similar evidence for the harmful effects of alcohol, tobacco, and amphetamine use, we considered the relation between observational evidence and action on cannabis. We examined arguments on the grounds of public health prudence for discouraging cannabis use by young individuals. With the assumption that the relation may be causal, we considered recommendations for policy in mental health services, health education, and public policy toward cannabis. RESULTS The observational evidence and biological plausibility of the hypothesis that cannabis is a contributory cause of psychosis is at least as strong as evidence for causal relations between heavy alcohol and amphetamine use and psychosis. On public health grounds, there is a good case for discouraging cannabis use among adolescents and young adults. It remains uncertain how best to discourage use and at whom campaigns to reduce cannabis use should be targeted. CONCLUSIONS We should discourage young adults seeking treatment in mental health services from using cannabis and inform them of the probable mental health risks of cannabis use, especially of early and frequent use. We must exercise caution in liberalizing cannabis laws in ways that may increase young individuals' access to cannabis, decrease their age of first use, or increase their frequency of cannabis use. We should consider the feasibility of reducing the availability of high-potency cannabis products.
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Affiliation(s)
- Wayne Hall
- School of Population Health, University of Queensland, Herston, Australia.
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Fu EJ, Cadenhead KS. Progress in the Prospective Study of the Schizophrenia Prodrome. CURRENT PSYCHOSIS & THERAPEUTICS REPORTS 2005; 3:169-174. [PMID: 21691454 PMCID: PMC3117596 DOI: 10.1007/bf02629450] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
Further understanding of the schizophrenia spectrum has helped to define the prodrome of the illness, leading to hopes of earlier identification and intervention in susceptible, at-risk individuals. Given the heterogeneity and comorbidity observed in the clinically and demographically identified prodromal sample, it is essential that neurobiological markers that are more closely linked to brain function, and perhaps the ability to predict evolution of psychosis, be identified. Ultimately, it may be possible to identify an algorithm of risk factors that will combine clinical and demographic risk factors with vulnerability markers associated with later development of schizophrenia to better target at-risk individuals or preventative treatment.
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Affiliation(s)
| | - Kristin S. Cadenhead
- Department of Psychiatry, 0810, University of California San Diego, 9500 Gilman Drive, La Jolla, CA 92093, USA
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Davidson M, Caspi A, Noy S. The treatment of schizophrenia: from premorbid manifestations to the first episode of psychosis. DIALOGUES IN CLINICAL NEUROSCIENCE 2005. [PMID: 16060592 PMCID: PMC3181721 DOI: 10.31887/dcns.2005.7.1/mdavidson] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
To achieve the best therapeutic results in schizophrenia--like most other disorders--primary prevention is preferable to early and prompt treatment, which, in turn, is preferable to treatment of chronically established illness. Unfortunately, there currently exist no accurate markers that can provide information regarding the future course of illness and guide treatment in asymptomatic or mildly symptomatic individuals. Therefore, most treatment efforts are currently focused on patients who have already experienced their first psychotic episode. This paper reviews the efforts to identify accurate markers heralding psychotic illness, as well as treatment considerations in the early phase of the disease.
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Affiliation(s)
- Michael Davidson
- Sackler School of Medicine, Tel Aviv University, Tel Aviv, Israel.
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26
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Davidson M, Caspi A, Noy S. The treatment of schizophrenia: from premorbid manifestations to the first episode of psychosis. DIALOGUES IN CLINICAL NEUROSCIENCE 2005; 7:7-16. [PMID: 16060592 PMCID: PMC3181721] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
To achieve the best therapeutic results in schizophrenia--like most other disorders--primary prevention is preferable to early and prompt treatment, which, in turn, is preferable to treatment of chronically established illness. Unfortunately, there currently exist no accurate markers that can provide information regarding the future course of illness and guide treatment in asymptomatic or mildly symptomatic individuals. Therefore, most treatment efforts are currently focused on patients who have already experienced their first psychotic episode. This paper reviews the efforts to identify accurate markers heralding psychotic illness, as well as treatment considerations in the early phase of the disease.
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Affiliation(s)
- Michael Davidson
- Sackler School of Medicine, Tel Aviv University, Tel Aviv, Israel.
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