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Hu W, Ran X, Wu Z, Zhu H, Kou Y, Zhang S, Yang G, Li W, Yang Y, Lv L, Zhang Y. Short-term antipsychotic treatment reduces functional connectivity of the striatum in first-episode drug-naïve early-onset schizophrenia. Schizophr Res 2024; 270:281-288. [PMID: 38944974 DOI: 10.1016/j.schres.2024.06.016] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/30/2023] [Revised: 04/24/2024] [Accepted: 06/15/2024] [Indexed: 07/02/2024]
Abstract
BACKGROUND The striatum is thought to play a critical role in the pathophysiology and antipsychotic treatment of schizophrenia. Previous studies have revealed abnormal functional connectivity (FC) of the striatum in early-onset schizophrenia (EOS) patients. However, no prior studies have examined post-treatment changes of striatal FC in EOS patients. METHODS We recruited 49 first-episode drug-naïve EOS patients to have resting-state functional magnetic resonance imaging scans at baseline and after 8 weeks of treatment with antipsychotics, along with baseline scanning of 34 healthy controls (HCs) for comparison purposes. We examined the FC values between each seed in striatal subregion and the rest of the brain. The Positive and Negative Syndrome Scale (PANSS) was applied to measure psychiatric symptoms in patients. RESULTS Compared with HCs at baseline, EOS patients exhibited weaker FC of striatal subregions with several brain regions of the salience network and default mode network. Meanwhile, FC between the dorsal caudal putamen (DCP) and left supplementary motor area, as well as between the DCP and right postcentral gyrus, was negatively correlated with PANSS negative scores. Furthermore, after 8 weeks of treatment, EOS patients showed decreased FC between subregions of the putamen and the triangular part of inferior frontal gyrus, middle frontal gyrus, supramarginal gyrus and inferior parietal lobule. CONCLUSIONS Decreased striatal FC is evident, even in the early stages of schizophrenia, and enhance our understanding of the neurodevelopmental abnormalities in schizophrenia. The findings also demonstrate that reduced striatal FC occurs after antipsychotic therapy, indicating that antipsychotic effects need to be accounted for when considering striatal FC abnormalities in schizophrenia.
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Affiliation(s)
- Wenyan Hu
- Department of Psychiatry, Henan Mental Hospital, The Second Affiliated Hospital of Xinxiang Medical University, Xinxiang 453002, China; Henan Key Lab of Biological Psychiatry, Xinxiang Medical University, Xinxiang 453002, China; International Joint Research Laboratory for Psychiatry and Neuroscience of Henan, Xinxiang 453002, China; Henan Collaborative Innovation Center of Prevention and Treatment of Mental Disorder, Xinxiang 453002, China
| | - Xiangying Ran
- School of Medical Engineering, Xinxiang Medical University, Xinxiang 453003, China
| | - Zhaoyang Wu
- Department of Psychiatry, Henan Mental Hospital, The Second Affiliated Hospital of Xinxiang Medical University, Xinxiang 453002, China; Henan Key Lab of Biological Psychiatry, Xinxiang Medical University, Xinxiang 453002, China; International Joint Research Laboratory for Psychiatry and Neuroscience of Henan, Xinxiang 453002, China; Henan Collaborative Innovation Center of Prevention and Treatment of Mental Disorder, Xinxiang 453002, China
| | - Hanyu Zhu
- Department of Psychiatry, Henan Mental Hospital, The Second Affiliated Hospital of Xinxiang Medical University, Xinxiang 453002, China; Henan Key Lab of Biological Psychiatry, Xinxiang Medical University, Xinxiang 453002, China; International Joint Research Laboratory for Psychiatry and Neuroscience of Henan, Xinxiang 453002, China; Henan Collaborative Innovation Center of Prevention and Treatment of Mental Disorder, Xinxiang 453002, China
| | - Yanna Kou
- Department of Psychiatry, Henan Mental Hospital, The Second Affiliated Hospital of Xinxiang Medical University, Xinxiang 453002, China; Henan Key Lab of Biological Psychiatry, Xinxiang Medical University, Xinxiang 453002, China; International Joint Research Laboratory for Psychiatry and Neuroscience of Henan, Xinxiang 453002, China; Henan Collaborative Innovation Center of Prevention and Treatment of Mental Disorder, Xinxiang 453002, China
| | - Sen Zhang
- Department of Psychiatry, Henan Mental Hospital, The Second Affiliated Hospital of Xinxiang Medical University, Xinxiang 453002, China; Henan Key Lab of Biological Psychiatry, Xinxiang Medical University, Xinxiang 453002, China; International Joint Research Laboratory for Psychiatry and Neuroscience of Henan, Xinxiang 453002, China; Henan Collaborative Innovation Center of Prevention and Treatment of Mental Disorder, Xinxiang 453002, China
| | - Ge Yang
- Department of Psychiatry, Henan Mental Hospital, The Second Affiliated Hospital of Xinxiang Medical University, Xinxiang 453002, China; Henan Key Lab of Biological Psychiatry, Xinxiang Medical University, Xinxiang 453002, China; International Joint Research Laboratory for Psychiatry and Neuroscience of Henan, Xinxiang 453002, China; Henan Collaborative Innovation Center of Prevention and Treatment of Mental Disorder, Xinxiang 453002, China
| | - Wenqiang Li
- Department of Psychiatry, Henan Mental Hospital, The Second Affiliated Hospital of Xinxiang Medical University, Xinxiang 453002, China; Henan Key Lab of Biological Psychiatry, Xinxiang Medical University, Xinxiang 453002, China; International Joint Research Laboratory for Psychiatry and Neuroscience of Henan, Xinxiang 453002, China; Henan Collaborative Innovation Center of Prevention and Treatment of Mental Disorder, Xinxiang 453002, China
| | - Yongfeng Yang
- Department of Psychiatry, Henan Mental Hospital, The Second Affiliated Hospital of Xinxiang Medical University, Xinxiang 453002, China; Henan Key Lab of Biological Psychiatry, Xinxiang Medical University, Xinxiang 453002, China; International Joint Research Laboratory for Psychiatry and Neuroscience of Henan, Xinxiang 453002, China; Henan Collaborative Innovation Center of Prevention and Treatment of Mental Disorder, Xinxiang 453002, China
| | - Luxian Lv
- Department of Psychiatry, Henan Mental Hospital, The Second Affiliated Hospital of Xinxiang Medical University, Xinxiang 453002, China; Henan Key Lab of Biological Psychiatry, Xinxiang Medical University, Xinxiang 453002, China; International Joint Research Laboratory for Psychiatry and Neuroscience of Henan, Xinxiang 453002, China; Henan Collaborative Innovation Center of Prevention and Treatment of Mental Disorder, Xinxiang 453002, China.
| | - Yan Zhang
- Department of Psychiatry, Henan Mental Hospital, The Second Affiliated Hospital of Xinxiang Medical University, Xinxiang 453002, China; Henan Key Lab of Biological Psychiatry, Xinxiang Medical University, Xinxiang 453002, China; International Joint Research Laboratory for Psychiatry and Neuroscience of Henan, Xinxiang 453002, China; Henan Collaborative Innovation Center of Prevention and Treatment of Mental Disorder, Xinxiang 453002, China.
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Cao X, Li Q, Liu S, Li Z, Wang Y, Cheng L, Yang C, Xu Y. Enhanced Resting-State Functional Connectivity of the Nucleus Accumbens in First-Episode, Medication-Naïve Patients With Early Onset Schizophrenia. Front Neurosci 2022; 16:844519. [PMID: 35401094 PMCID: PMC8990232 DOI: 10.3389/fnins.2022.844519] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2021] [Accepted: 02/01/2022] [Indexed: 01/10/2023] Open
Abstract
There is abundant evidence that early onset schizophrenia (EOS) is associated with abnormalities in widespread regions, including the cortical, striatal, and limbic areas. As a main component of the ventral striatum, the nucleus accumbens (NAc) is implicated in the pathology of schizophrenia. However, functional connection patterns of NAc in patients with schizophrenia, especially EOS, are seldom explored. A total of 78 first-episode, medication-naïve patients with EOS and 90 healthy controls were recruited in the present study, and resting-state, seed-based functional connectivity (FC) analyses were performed to investigate temporal correlations between NAc and the rest of the brain in the two groups. Additionally, correlation analyses were done between regions showing group differences in NAc functional integration and clinical features of EOS. Group comparison found enhanced FC of the NAc in the EOS group relative to the HCs with increased FC in the right superior temporal gyrus and left superior parietal gyrus with the left NAc region of interest (ROI) and elevated FC in left middle occipital gyrus with the right NAc ROI. No significant associations were found between FC strength and symptom severity as well as the age of the patients. Our findings reveal abnormally enhanced FC of the NAc with regions located in the temporal, parietal, and occipital areas, which were implicated in auditory/visual processing, sensorimotor integration, and cognitive functions. The results suggest disturbed relationships between regions subserving reward, salience processing, and regions subserving sensory processing as well as cognitive functions, which may deepen our understanding of the role of NAc in the pathology of EOS.
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Affiliation(s)
- Xiaohua Cao
- Department of Psychiatry, First Hospital/First Clinical Medical College of Shanxi Medical University, Taiyuan, China
| | - Qiang Li
- Shanxi Provincial Corps Hospital of Chinese People’s Armed Police Force, Taiyuan, China
| | - Sha Liu
- Department of Psychiatry, First Hospital/First Clinical Medical College of Shanxi Medical University, Taiyuan, China
- Shanxi Key Laboratory of Artificial Intelligence Assisted Diagnosis and Treatment for Mental Disorder, First Hospital of Shanxi Medical University, Taiyuan, China
| | - Zexuan Li
- Shanxi Key Laboratory of Artificial Intelligence Assisted Diagnosis and Treatment for Mental Disorder, First Hospital of Shanxi Medical University, Taiyuan, China
| | - Yanfang Wang
- Department of Psychiatry, First Hospital/First Clinical Medical College of Shanxi Medical University, Taiyuan, China
| | - Long Cheng
- Department of Psychiatry, First Hospital/First Clinical Medical College of Shanxi Medical University, Taiyuan, China
| | - Chengxiang Yang
- Department of Psychiatry, Shanxi Bethune Hospital, Taiyuan, China
| | - Yong Xu
- Department of Psychiatry, First Hospital/First Clinical Medical College of Shanxi Medical University, Taiyuan, China
- Department of Mental Health, Shanxi Medical University, Taiyuan, China
- Shanxi Provincial Key Laboratory of Brain Science and Neuropsychiatric Diseases, Taiyuan, China
- *Correspondence: Yong Xu, ;
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Vázquez-Borsetti P, Acuña A, Soliño M, López-Costa JJ, Kargieman L, Loidl FC. Deep hypothermia prevents striatal alterations produced by perinatal asphyxia: Implications for the prevention of dyskinesia and psychosis. J Comp Neurol 2020; 528:2679-2694. [PMID: 32301107 DOI: 10.1002/cne.24925] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2019] [Revised: 03/25/2020] [Accepted: 03/26/2020] [Indexed: 12/23/2022]
Abstract
GABAergic medium spiny neurons are the main neuronal population in the striatum. Calbindin is preferentially expressed in medium spiny neurons involved in the indirect pathway. The aim of the present work is to analyze the effect of perinatal asphyxia on different subpopulations of GABAergic neurons in the striatum and to assess the outcome of deep therapeutic hypothermia. The uterus of pregnant rats was removed by cesarean section and the fetuses were exposed to hypoxia by immersion in water (19 min) at 37°C (perinatal asphyxia). The hypothermic group was exposed to 10°C during 30 min after perinatal asphyxia. The rats were euthanized at the age of one month (adolescent/adult rats), their brains were dissected out and coronal sections were immunolabeled for calbindin, calretinin, NeuN, and reelin. Reelin+ cells showed no staining in the striatum besides subventricular zone. The perinatal asphyxia (PA) group showed a significant decrease in calbindin neurons and a paradoxical increase in neurons estimated by NeuN staining. Moreover, calretinin+ cells, a specific subpopulation of GABAergic neurons, showed an increase caused by PA. Deep hypothermia reversed most of these alterations probably by protecting calbindin neurons. Similarly, there was a reduction of the diameter of the anterior commissure produced by the asphyxia that was prevented by hypothermic treatment.
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Affiliation(s)
- Pablo Vázquez-Borsetti
- Laboratorio de Neuropatología Experimental, Instituto de Biología Celular y Neurociencia "Prof. E. De Robertis", UBA-CONICET, Buenos Aires, Argentina
| | - Andrés Acuña
- Laboratorio de Neuropatología Experimental, Instituto de Biología Celular y Neurociencia "Prof. E. De Robertis", UBA-CONICET, Buenos Aires, Argentina
| | - Manuel Soliño
- Laboratorio de Neuropatología Experimental, Instituto de Biología Celular y Neurociencia "Prof. E. De Robertis", UBA-CONICET, Buenos Aires, Argentina
| | - Juan José López-Costa
- Laboratorio de Neuropatología Experimental, Instituto de Biología Celular y Neurociencia "Prof. E. De Robertis", UBA-CONICET, Buenos Aires, Argentina
| | - Lucila Kargieman
- IFIBYNE (UBA-CONICET) Instituto de Fisiología, Biología Molecular y Neurociencias-Universidad de Buenos Aires, Buenos Aires, Argentina
| | - Fabián César Loidl
- Laboratorio de Neuropatología Experimental, Instituto de Biología Celular y Neurociencia "Prof. E. De Robertis", UBA-CONICET, Buenos Aires, Argentina
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Bonaccorso S, Ricciardi A, Zangani C, Chiappini S, Schifano F. Cannabidiol (CBD) use in psychiatric disorders: A systematic review. Neurotoxicology 2019; 74:282-298. [PMID: 31412258 DOI: 10.1016/j.neuro.2019.08.002] [Citation(s) in RCA: 88] [Impact Index Per Article: 17.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2019] [Revised: 08/02/2019] [Accepted: 08/04/2019] [Indexed: 12/21/2022]
Abstract
Cannabidiol (CBD) and Δ9-tetrahydrocannabinol (THC) are the most represented phytocannabinoids in Cannabis sativa plants. However, CBD may present with a different activity compared with the psychotomimetic THC. Most typically, CBD is reported to be used in some medical conditions, including chronic pain. Conversely, the main aim of this systematic review is to assess and summarise the available body of evidence relating to both efficacy and safety of CBD as a treatment for psychiatric disorders, alone and/or in combination with other treatments. Eligible studies included randomized controlled trials (RCT) assessing the effect of CBD in a range of psychopathological conditions, such as substance use; psychosis, anxiety, mood disturbances, and other psychiatric (e.g., cognitive impairment; sleep; personality; eating; obsessive-compulsive; post-traumatic stress/PTSD; dissociative; and somatic) disorders. For data gathering purposes, the PRISMA guidelines were followed. The initial search strategy identified some n = 1301 papers; n = 190 studies were included after the abstract's screening and n = 27 articles met the inclusion criteria. There is currently limited evidence regarding the safety and efficacy of CBD for the treatment of psychiatric disorders. However, available trials reported potential therapeutic effects for specific psychopathological conditions, such as substance use disorders, chronic psychosis, and anxiety. Further large-scale RCTs are required to better evaluate the efficacy of CBD in both acute and chronic illnesses, special categories, as well as to exclude any possible abuse liability.
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Affiliation(s)
| | - Angelo Ricciardi
- Camden and Islington NHS Mental Health Foundation Trust, London, UK; Department of Mental Health, ASL Roma 1, Rome, Italy
| | - Caroline Zangani
- Psychopharmacology, Drug Misuse and Novel Psychoactive Substances Research Unit, School of Life and Medical Sciences, University of Hertfordshire, Hatfield, UK
| | - Stefania Chiappini
- Psychopharmacology, Drug Misuse and Novel Psychoactive Substances Research Unit, School of Life and Medical Sciences, University of Hertfordshire, Hatfield, UK
| | - Fabrizio Schifano
- Psychopharmacology, Drug Misuse and Novel Psychoactive Substances Research Unit, School of Life and Medical Sciences, University of Hertfordshire, Hatfield, UK
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5
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Katagiri N, Pantelis C, Nemoto T, Tsujino N, Saito J, Hori M, Yamaguchi T, Funatogawa T, Mizuno M. Longitudinal changes in striatum and sub-threshold positive symptoms in individuals with an 'at risk mental state' (ARMS). Psychiatry Res Neuroimaging 2019; 285:25-30. [PMID: 30716687 DOI: 10.1016/j.pscychresns.2019.01.008] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/28/2018] [Revised: 12/23/2018] [Accepted: 01/26/2019] [Indexed: 10/27/2022]
Abstract
Recent studies have revealed that several psychotic symptom changes observed in the 'at risk mental state' (ARMS) are associated with changes in the striatum. We investigated if structural changes in the striatum are associated with recovery of sub-threshold psychotic symptoms in subjects with an ARMS who did not develop psychosis (ARMS-N). Sixteen healthy controls and 42 subjects with an ARMS participated in this study. Striatal volumes (caudate, putamen, and nucleus accumbens) were analyzed using MRI. The sub-threshold psychotic symptoms of the subjects with an ARMS were measured using the SOPS. Imaging and symptoms were reevaluated after 52 weeks. Significant right putamen volume reduction was observed at the follow-up in ARMS-N subjects. Improvement in sub-threshold positive symptoms significantly correlated with an increase in volume in the right accumbens at follow up. No relationship was found for negative symptoms. From these findings, the association between improvement in sub-threshold positive symptoms and an increase in the volume of the right accumbens may suggest that changes in the accumbens, which is a major site for dopamine innervation, are associated with symptom recovery. These findings may point to neurobiological resilience that may be associated with lower transition to psychosis.
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Affiliation(s)
- Naoyuki Katagiri
- Department of Neuropsychiatry, School of Medicine, Toho University, 6-11-1 Omori-nishi, Ota-ku, 143-8541, Tokyo, Japan.
| | - Christos Pantelis
- Melbourne Neuropsychiatry Centre, Department of Psychiatry, The University of Melbourne & Melbourne Health, Carlton South, Victoria, Australia; Centre for Neural Engineering, Department of Electrical and Electronic Engineering, University of Melbourne, Carlton South, Victoritoka, Australia
| | - Takahiro Nemoto
- Department of Neuropsychiatry, School of Medicine, Toho University, 6-11-1 Omori-nishi, Ota-ku, 143-8541, Tokyo, Japan
| | - Naohisa Tsujino
- Department of Neuropsychiatry, School of Medicine, Toho University, 6-11-1 Omori-nishi, Ota-ku, 143-8541, Tokyo, Japan; Saiseikai Yokohamashi Tobu Hospital Psychiatry, Yokohama-City, Kanagawa, Japan
| | - Junichi Saito
- Department of Neuropsychiatry, School of Medicine, Toho University, 6-11-1 Omori-nishi, Ota-ku, 143-8541, Tokyo, Japan; Saiseikai Yokohamashi Tobu Hospital Psychiatry, Yokohama-City, Kanagawa, Japan
| | - Masaaki Hori
- Department of Radiology, Juntendo University School of Medicine, Bunkyo-ku, Tokyo, Japan
| | - Taiju Yamaguchi
- Department of Neuropsychiatry, School of Medicine, Toho University, 6-11-1 Omori-nishi, Ota-ku, 143-8541, Tokyo, Japan
| | - Tomoyuki Funatogawa
- Department of Neuropsychiatry, School of Medicine, Toho University, 6-11-1 Omori-nishi, Ota-ku, 143-8541, Tokyo, Japan
| | - Masafumi Mizuno
- Department of Neuropsychiatry, School of Medicine, Toho University, 6-11-1 Omori-nishi, Ota-ku, 143-8541, Tokyo, Japan
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Rominger C, Schulter G, Fink A, Weiss EM, Papousek I. Meaning in meaninglessness: The propensity to perceive meaningful patterns in coincident events and randomly arranged stimuli is linked to enhanced attention in early sensory processing. Psychiatry Res 2018; 263:225-232. [PMID: 29179910 DOI: 10.1016/j.psychres.2017.07.043] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/16/2016] [Revised: 07/21/2017] [Accepted: 07/24/2017] [Indexed: 01/19/2023]
Abstract
Perception of objectively independent events or stimuli as being significantly connected and the associated proneness to perceive meaningful patterns constitute part of the positive symptoms of schizophrenia, which are associated with altered attentional processes in lateralized speech perception. Since perceiving meaningful patterns is to some extent already prevalent in the general population, the aim of the study was to investigate whether the propensity to experience meaningful patterns in co-occurring events and random stimuli may be associated with similar altered attentional processes in lateralized speech perception. Self-reported and behavioral indicators of the perception of meaningful patterns were assessed in non-clinical individuals, along with EEG auditory evoked potentials during the performance of an attention related lateralized speech perception task (Dichotic Listening Test). A greater propensity to perceive meaningful patterns was associated with higher N1 amplitudes of the evoked potentials to the onset of the dichotically presented consonant-vowel syllables, indicating enhanced automatic attention in early sensory processing. The study suggests that more basic mechanisms in how people associate events may play a greater role in the cognitive biases that are manifest in personality expressions such as positive schizotypy, rather than that positive schizotypy moderates these cognitive biases directly.
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Affiliation(s)
- Christian Rominger
- Department of Psychology, Biological Psychology Unit, University of Graz, Austria.
| | - Günter Schulter
- Department of Psychology, Biological Psychology Unit, University of Graz, Austria
| | - Andreas Fink
- Department of Psychology, Biological Psychology Unit, University of Graz, Austria
| | - Elisabeth M Weiss
- Department of Psychology, Biological Psychology Unit, University of Graz, Austria
| | - Ilona Papousek
- Department of Psychology, Biological Psychology Unit, University of Graz, Austria
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Fujimaki K, Toki S, Yamashita H, Oyamada T, Yamawaki S. Predictors of negative symptoms in the chronic phase of schizophrenia: A cross-sectional study. Psychiatry Res 2018; 262:600-608. [PMID: 28965809 DOI: 10.1016/j.psychres.2017.09.051] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/29/2017] [Revised: 09/19/2017] [Accepted: 09/22/2017] [Indexed: 11/15/2022]
Abstract
This study was designed to investigate the relationship between negative symptoms and key indicators for long-term hospital stays among inpatients with schizophrenia. A further aim was to elucidate the clinical determinants of negative symptoms. The following were used as index factors: age, duration of illness, duration of hospitalization, age at onset, years of education, smoking status, body mass index, concentrations of serum triglycerides, total cholesterol, uric acid, QTc interval duration from electrocardiography, dose equivalents of antipsychotic and anticholinergic agents, neurocognitive function, drug-induced extrapyramidal symptoms, involuntary movements, and psychiatric symptoms. Spearman's rank correlation coefficients were calculated and regression analyses were performed to examine associations between these factors and negative symptoms. Positive symptoms correlated positively with negative symptoms as rated on the Brief Psychiatric Rating Scale. Age at onset correlated negatively with negative symptoms. Multiple regression analysis showed that dose equivalents of atypical antipsychotics and positive symptoms predicted negative symptoms. Increasing our understanding of these predictors as key indicators of the severity of negative symptoms may aid in the reconsideration of therapeutic programs for chronic schizophrenia.
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Affiliation(s)
- Koichiro Fujimaki
- Faculty of Health and Welfare, Prefectural University of Hiroshima, Mihara, Japan.
| | | | - Hidehisa Yamashita
- Department of Psychiatry and Neurosciences, Division of Frontier Medical Science, Programs for Biomedical Research, Graduate School of Biomedical Sciences, Hiroshima University, Hiroshima, Japan
| | | | - Shigeto Yamawaki
- Department of Psychiatry and Neurosciences, Division of Frontier Medical Science, Programs for Biomedical Research, Graduate School of Biomedical Sciences, Hiroshima University, Hiroshima, Japan
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8
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Challenges and opportunities for the development of new antipsychotic drugs. Biochem Pharmacol 2017; 143:10-24. [DOI: 10.1016/j.bcp.2017.05.009] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2017] [Accepted: 05/12/2017] [Indexed: 12/20/2022]
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Forns-Nadal M, Bergé D, Sem F, Mané A, Igual L, Guinart D, Vilarroya O. Increased nucleus accumbens volume in first-episode psychosis. Psychiatry Res Neuroimaging 2017; 263:57-60. [PMID: 28340425 DOI: 10.1016/j.pscychresns.2017.03.007] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/14/2016] [Revised: 02/13/2017] [Accepted: 03/17/2017] [Indexed: 12/23/2022]
Abstract
Nucleus accumbens has been reported as a key structure in the neurobiology of schizophrenia. Studies analyzing structural abnormalities have shown conflicting results, possibly related to confounding factors. We investigated the nucleus accumbens volume using manual delimitation in first-episode psychosis (FEP) controlling for age, cannabis use and medication. Thirty-one FEP subjects who were naive or minimally exposed to antipsychotics and a control group were MRI scanned and clinically assessed from baseline to 6 months of follow-up. FEP showed increased relative and total accumbens volumes. Clinical correlations with negative symptoms, duration of untreated psychosis and cannabis use were not significant.
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Affiliation(s)
- Mireia Forns-Nadal
- Department of Cognitive Neuroscience and Information Technologies, Internet Interdisciplinary Institute, Open University of Catalonia, Barcelona, Spain
| | - Daniel Bergé
- Neuroscience group, Hospital del Mar Medical Research Institute (IMIM), Barcelona, Spain; Departament de Psiquiatria i Medicina Legal, Facultat de Medicina, Universitat Autònoma de Barcelona, Campus de Bellaterra, Cerdanyola del Vallès, Spain; CIBERSAM, Barcelona, Spain.
| | - Federico Sem
- Department of Applied Mathematics and Analysis of the University of Barcelona, Barcelona, Spain
| | - Anna Mané
- Neuroscience group, Hospital del Mar Medical Research Institute (IMIM), Barcelona, Spain; CIBERSAM, Barcelona, Spain
| | - Laura Igual
- Department of Applied Mathematics and Analysis of the University of Barcelona, Barcelona, Spain; Computer Vision Center, Edificio O, Universitat Autònoma de Barcelona, Campus de Bellaterra, s/n, Cerdanyola del Vallès, Spain
| | - Dani Guinart
- Neuroscience group, Hospital del Mar Medical Research Institute (IMIM), Barcelona, Spain; Departament de Psiquiatria i Medicina Legal, Facultat de Medicina, Universitat Autònoma de Barcelona, Campus de Bellaterra, Cerdanyola del Vallès, Spain
| | - Oscar Vilarroya
- Neuroscience group, Hospital del Mar Medical Research Institute (IMIM), Barcelona, Spain; Departament de Psiquiatria i Medicina Legal, Facultat de Medicina, Universitat Autònoma de Barcelona, Campus de Bellaterra, Cerdanyola del Vallès, Spain
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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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11
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Gene × Environment Interactions in Schizophrenia: Evidence from Genetic Mouse Models. Neural Plast 2016; 2016:2173748. [PMID: 27725886 PMCID: PMC5048038 DOI: 10.1155/2016/2173748] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2016] [Revised: 07/20/2016] [Accepted: 08/21/2016] [Indexed: 02/06/2023] Open
Abstract
The study of gene × environment, as well as epistatic interactions in schizophrenia, has provided important insight into the complex etiopathologic basis of schizophrenia. It has also increased our understanding of the role of susceptibility genes in the disorder and is an important consideration as we seek to translate genetic advances into novel antipsychotic treatment targets. This review summarises data arising from research involving the modelling of gene × environment interactions in schizophrenia using preclinical genetic models. Evidence for synergistic effects on the expression of schizophrenia-relevant endophenotypes will be discussed. It is proposed that valid and multifactorial preclinical models are important tools for identifying critical areas, as well as underlying mechanisms, of convergence of genetic and environmental risk factors, and their interaction in schizophrenia.
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Huijbregts SCJ, Griffith-Lendering MFH, Vollebergh WAM, Swaab H. Neurocognitive moderation of associations between cannabis use and psychoneuroticism. J Clin Exp Neuropsychol 2014; 36:794-805. [DOI: 10.1080/13803395.2014.943694] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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O'Tuathaigh CMP, Gantois I, Waddington JL. Genetic dissection of the psychotomimetic effects of cannabinoid exposure. Prog Neuropsychopharmacol Biol Psychiatry 2014; 52:33-40. [PMID: 24239593 DOI: 10.1016/j.pnpbp.2013.11.002] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/03/2013] [Revised: 10/31/2013] [Accepted: 11/04/2013] [Indexed: 12/31/2022]
Abstract
Cannabis use is an established risk factor for the development of schizophrenia and related psychotic disorders. Factors that may mediate susceptibility to the psychosis-inducing effects of cannabis include the age at onset of first cannabis use, genetic predisposition, as well as interaction with other environmental risk variables. Clinical and preclinical genetic studies provide increasing evidence that, in particular, genes encoding proteins implicated in dopamine signalling are implicated in the cannabis-psychosis association. In the present review, we focus on both human and animal studies which have focused on identifying the neuronal basis of these interactions. We conclude that further studies are required to provide greater mechanistic insight into the long-term and neurodevelopmental effects of cannabis use, with implications for improved understanding of the cannabis-psychosis relationship.
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Affiliation(s)
- Colm M P O'Tuathaigh
- Molecular & Cellular Therapeutics, Royal College of Surgeons in Ireland, Dublin 2, Ireland; School of Medicine, University College Cork, Cork, Ireland.
| | - Ilse Gantois
- Laboratory of Biological Psychology, KU Leuven, 3000 Leuven, Belgium
| | - John L Waddington
- Molecular & Cellular Therapeutics, Royal College of Surgeons in Ireland, Dublin 2, Ireland
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van Winkel R, Kuepper R. Epidemiological, neurobiological, and genetic clues to the mechanisms linking cannabis use to risk for nonaffective psychosis. Annu Rev Clin Psychol 2014; 10:767-91. [PMID: 24471373 DOI: 10.1146/annurev-clinpsy-032813-153631] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Epidemiological studies have shown that the association between cannabis and psychosis is robust and consistent across different samples, with compelling evidence for a dose-response relationship. Because longitudinal work indicates that cannabis use precedes psychotic symptoms, it seems reasonable to assume a causal relationship. However, more work is needed to address the possibility of gene-environment correlation (for example, genetic risk for psychosis causing onset of cannabis use). Moreover, knowledge about underlying biological mechanisms linking cannabis use and psychosis is still relatively limited. In order to understand how cannabis use may lead to an increased risk for psychosis, in the present article we (a) review the epidemiological, neurobiological, and genetic evidence linking cannabinoids and psychosis, (b) assess the quality of the evidence, and finally (c) try to integrate the most robust findings into a neurodevelopmental model of cannabis-induced psychosis and identify the gaps in knowledge that are in need of further investigation.
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Affiliation(s)
- Ruud van Winkel
- Department of Psychiatry and Psychology, School of Mental Health and Neuroscience, European Graduate School of Neuroscience (EURON), South Limburg Mental Health Research and Teaching Network (SEARCH), Maastricht University Medical Center, Maastricht, The Netherlands;
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15
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Stegmayer K, Horn H, Federspiel A, Razavi N, Bracht T, Laimböck K, Strik W, Dierks T, Wiest R, Müller TJ, Walther S. Ventral striatum gray matter density reduction in patients with schizophrenia and psychotic emotional dysregulation. NEUROIMAGE-CLINICAL 2013; 4:232-9. [PMID: 24455473 PMCID: PMC3895617 DOI: 10.1016/j.nicl.2013.12.007] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/17/2013] [Revised: 12/09/2013] [Accepted: 12/17/2013] [Indexed: 01/26/2023]
Abstract
Introduction Substantial heterogeneity remains across studies investigating changes in gray matter in schizophrenia. Differences in methodology, heterogeneous symptom patterns and symptom trajectories may contribute to inconsistent findings. To address this problem, we recently proposed to group patients by symptom dimensions, which map on the language, the limbic and the motor systems. The aim of the present study was to investigate whether patients with prevalent symptoms of emotional dysregulation would show structural neuronal abnormalities in the limbic system. Method 43 right-handed medicated patients with schizophrenia were assessed with the Bern Psychopathology Scale (BPS). The patients and a control group of 34 healthy individuals underwent structural imaging at a 3T MRI scanner. Whole brain voxel-based morphometry (VBM) was compared between patient subgroups with different severity of emotional dysregulation. Group comparisons (comparison between patients with severe emotional dysregulation, patients with mild emotional dysregulation, patients with no emotional dysregulation and healthy controls) were performed using a one way ANOVA and ANCOVA respectively. Results Patients with severe emotional dysregulation had significantly decreased gray matter density in a large cluster including the right ventral striatum and the head of the caudate compared to patients without emotional dysregulation. Comparing patients with severe emotional dysregulation and healthy controls, several clusters of significant decreased GM density were detected in patients, including the right ventral striatum, head of the caudate, left hippocampus, bilateral thalamus, dorsolateral prefrontal and orbitofrontal cortex. The significant effect in the ventral striatum was lost when patients with and without emotional dysregulation were pooled and compared with controls. Discussion Decreased gray matter density in a large cluster including the right ventral striatum was associated with severe symptoms of emotional dysregulation in patients with schizophrenia. The ventral striatum is an important part of the limbic system, and was indicated to be involved in the generation of incentive salience and psychotic symptoms. Only patients with severe emotional dysregulation had decreased gray matter in several brain structures associated with emotion and reward processing compared to healthy controls. The results support the hypothesis that grouping patients according to specific clinical symptoms matched to the limbic system allows identifying patient subgroups with structural abnormalities in the limbic network. We examined whole brain VBM in schizophrenia patients and healthy controls. We compared patients with different severity of emotional dysregulation (ED). Symptoms of ED were associated with GM density in the ventral striatum. Grouping patients according to symptoms identified specific GM abnormalities.
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Affiliation(s)
| | - Helge Horn
- University Hospital of Psychiatry, Bern, Switzerland
| | | | - Nadja Razavi
- University Hospital of Psychiatry, Bern, Switzerland
| | - Tobias Bracht
- University Hospital of Psychiatry, Bern, Switzerland
| | | | - Werner Strik
- University Hospital of Psychiatry, Bern, Switzerland
| | - Thomas Dierks
- University Hospital of Psychiatry, Bern, Switzerland
| | - Roland Wiest
- Support Center of Advanced Neuroimaging (SCAN), University Institute of Diagnostic and Interventional Neuroradiology, Inselspital, Bern, Switzerland
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Bentsen H, Osnes K, Refsum H, Solberg DK, Bøhmer T. A randomized placebo-controlled trial of an omega-3 fatty acid and vitamins E+C in schizophrenia. Transl Psychiatry 2013; 3:e335. [PMID: 24346133 PMCID: PMC3906471 DOI: 10.1038/tp.2013.110] [Citation(s) in RCA: 59] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/07/2013] [Revised: 10/09/2013] [Accepted: 10/21/2013] [Indexed: 02/07/2023] Open
Abstract
Membrane lipid metabolism and redox regulation may be disturbed in schizophrenia. We examined the clinical effect of adding an omega-3 fatty acid and/or vitamins E+C to antipsychotics. It was hypothesized that lower baseline levels of polyunsaturated fatty acids (PUFAs) would predict more benefit from the add-on treatment. The trial had a multicenter, randomized, double-blind, placebo-controlled 2 × 2 factorial design. Patients aged 18-39 years with schizophrenia or related psychoses were consecutively included at admission to psychiatric departments in Norway. They received active or placebo ethyl-eicosapentaenoate (EPA) 2 g day⁻¹ and active or placebo vitamin E 364 mg day⁻¹+vitamin C 1000 mg day⁻¹ (vitamins) for 16 weeks. The main outcome measures were Positive and Negative Syndrome Scale (PANSS) total and subscales scores, analyzed by linear mixed models. Ninety-nine patients were included. At baseline, erythrocyte PUFA were measured in 97 subjects. Given separately, EPA and vitamins increased drop-out rates, whereas when combined they did not differ from placebo. In low PUFA patients, EPA alone impaired the course of total PANSS (Cohen's d=0.29; P=0.03) and psychotic symptoms (d=0.40; P=0.003), especially persecutory delusions (d=0.48; P=0.0004). Vitamins alone impaired the course of psychotic symptoms (d= 0.37; P=0.005), especially persecutory delusions (d=0.47; P=0.0005). Adding vitamins to EPA neutralized the detrimental effect on psychosis (interaction d=0.31; P=0.02). In high PUFA patients, there were no significant effects of trial drugs on PANSS scales. In conclusion, given separately during an acute episode, EPA and vitamins E+C induce psychotic symptoms in patients with low levels of PUFA. Combined, these agents seem safe.
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Affiliation(s)
- H Bentsen
- Center for Psychopharmacology, Diakonhjemmet Hospital, Oslo, Norway,Division of Psychiatry, Oslo University Hospital, Aker, Oslo, Norway,Center for Psychopharmacology, Diakonhjemmet Hospital, P.o.b. 85, Vinderen, Oslo 0319, Norway. E-mail:
| | - K Osnes
- Department of Psychosomatic Medicine, Oslo University Hospital, Rikshospitalet, Oslo, Norway
| | - H Refsum
- Center for Psychopharmacology, Diakonhjemmet Hospital, Oslo, Norway
| | - D K Solberg
- Center for Psychopharmacology, Diakonhjemmet Hospital, Oslo, Norway
| | - T Bøhmer
- Nutritional Laboratory, Department of Medical Biochemistry, Oslo University Hospital, Aker, Oslo, Norway
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Harkness AR, Reynolds SM, Lilienfeld SO. A review of systems for psychology and psychiatry: adaptive systems, personality psychopathology five (PSY-5), and the DSM-5. J Pers Assess 2013; 96:121-39. [PMID: 23941204 DOI: 10.1080/00223891.2013.823438] [Citation(s) in RCA: 50] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
We outline a crisis in clinical description, in which atheoretical categorical descriptors, as in the Diagnostic and Statistical Manual of Mental Disorders (DSM), has turned focus away from the obvious: evolved major adaptive systems. Adaptive systems, at the core of a medical review of systems (ROS), allow models of pathology to be layered over an understanding of systems as they normally function. We argue that clinical psychology and psychiatry would develop more programmatically by incorporating 5 systems evolved for adaptation to the external environment: reality modeling for action, short-term danger detection, long-term cost-benefit projection, resource acquisition, and agenda protection. These systems, although not exhaustive, coincide with great historical issues in psychology, psychopathology, and individual differences. Readers of this journal should be interested in this approach because personality is seen as a relatively stable property of these systems. Thus, an essential starting point in ROS-based clinical description involves personality assessment. But this approach also places demands on scientist-practitioners to integrate across sciences. An ROS promotes theories that are (a) compositional, answering the question: What elements comprise the system?; (b) dynamic, answering: How do the elements and other systems interact?; and (c) developmental: How do systems change over time? The proposed ROS corresponds well with the National Institute of Mental Health's recent research domain criteria (RDoC) approach. We urge that in the RDoC approach, measurement variables should be treated as falsifiable and theory-laden markers, not unfalsifiable criteria. We argue that our proposed ROS promotes integration across sciences, rather than fostering the isolation of sciences allowed by atheoretical observation terms, as in the DSM.
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Affiliation(s)
- Allan R Harkness
- a Department of Psychology and Institute for Biochemical and Psychological Study of Individual Differences , The University of Tulsa
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18
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Kuepper R, Ceccarini J, Lataster J, van Os J, van Kroonenburgh M, van Gerven JMA, Marcelis M, Van Laere K, Henquet C. Delta-9-tetrahydrocannabinol-induced dopamine release as a function of psychosis risk: 18F-fallypride positron emission tomography study. PLoS One 2013; 8:e70378. [PMID: 23936196 PMCID: PMC3723813 DOI: 10.1371/journal.pone.0070378] [Citation(s) in RCA: 62] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2012] [Accepted: 06/18/2013] [Indexed: 11/18/2022] Open
Abstract
Cannabis use is associated with psychosis, particularly in those with expression of, or vulnerability for, psychotic illness. The biological underpinnings of these differential associations, however, remain largely unknown. We used Positron Emission Tomography and (18)F-fallypride to test the hypothesis that genetic risk for psychosis is expressed by differential induction of dopamine release by Δ(9)-THC (delta-9-tetrahydrocannabinol, the main psychoactive ingredient of cannabis). In a single dynamic PET scanning session, striatal dopamine release after pulmonary administration of Δ(9)-THC was measured in 9 healthy cannabis users (average risk psychotic disorder), 8 patients with psychotic disorder (high risk psychotic disorder) and 7 un-related first-degree relatives (intermediate risk psychotic disorder). PET data were analyzed applying the linear extension of the simplified reference region model (LSRRM), which accounts for time-dependent changes in (18)F-fallypride displacement. Voxel-based statistical maps, representing specific D2/3 binding changes, were computed to localize areas with increased ligand displacement after Δ(9)-THC administration, reflecting dopamine release. While Δ(9)-THC was not associated with dopamine release in the control group, significant ligand displacement induced by Δ(9)-THC in striatal subregions, indicative of dopamine release, was detected in both patients and relatives. This was most pronounced in caudate nucleus. This is the first study to demonstrate differential sensitivity to Δ(9)-THC in terms of increased endogenous dopamine release in individuals at risk for psychosis.
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Affiliation(s)
- Rebecca Kuepper
- Department of Psychiatry and Psychology, South Limburg Mental Health Research and Teaching Network, EURON, Maastricht University, Maastricht, The Netherlands.
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Griffith-Lendering MFH, Wigman JTW, Prince van Leeuwen A, Huijbregts SCJ, Huizink AC, Ormel J, Verhulst FC, van Os J, Swaab H, Vollebergh WAM. Cannabis use and vulnerability for psychosis in early adolescence--a TRAILS study. Addiction 2013; 108:733-40. [PMID: 23216690 DOI: 10.1111/add.12050] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/08/2011] [Revised: 12/06/2011] [Accepted: 10/23/2012] [Indexed: 11/30/2022]
Abstract
AIMS To examine the direction of the longitudinal association between vulnerability for psychosis and cannabis use throughout adolescence. DESIGN Cross-lagged path analysis was used to identify the temporal order of vulnerability for psychosis and cannabis use, while controlling for gender, family psychopathology, alcohol use and tobacco use. SETTING A large prospective population study of Dutch adolescents [the TRacking Adolescents' Individual Lives Survey (TRAILS) study]. PARTICIPANTS A total of 2120 adolescents with assessments at (mean) age 13.6, age 16.3 and age 19.1. MEASUREMENTS Vulnerability for psychosis at the three assessment points was represented by latent factors derived from scores on three scales of the Youth Self-Report and the Adult Self-Report, i.e. thought problems, social problems and attention problems. Participants self-reported on cannabis use during the past year at all three waves. FINDINGS Significant associations (r = 0.12-0.23) were observed between psychosis vulnerability and cannabis use at all assessments. Also, cannabis use at age 16 predicted psychosis vulnerability at age 19 (Z = 2.6, P < 0.05). Furthermore, psychosis vulnerability at ages 13 (Z = 2.0, P < 0.05) and 16 (Z = 3.0, P < 0.05) predicted cannabis use at, respectively, ages 16 and 19. CONCLUSIONS Cannabis use predicts psychosis vulnerability in adolescents and vice versa, which suggests that there is a bidirectional causal association between the two.
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Affiliation(s)
- Merel F H Griffith-Lendering
- Department of Clinical Child and Adolescent Studies, Faculty of Social Sciences, Leiden University, Leiden, the Netherlands.
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Mizuno M, Sotoyama H, Namba H, Shibuya M, Eda T, Wang R, Okubo T, Nagata K, Iwakura Y, Nawa H. ErbB inhibitors ameliorate behavioral impairments of an animal model for schizophrenia: implication of their dopamine-modulatory actions. Transl Psychiatry 2013; 3:e252. [PMID: 23632456 PMCID: PMC3641415 DOI: 10.1038/tp.2013.29] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Ligands for ErbB receptors, including epidermal growth factor (EGF) and neuregulin-1, have a neurotrophic activity on midbrain dopaminergic neurons and are implicated in the pathophysiology of schizophrenia. Although ErbB kinase inhibitors ameliorate behavioral deficits of the schizophrenia model that was established by hippocampal lesioning of rat pups, the antipsychotic action of ErbB kinase inhibitors and its general applicability to other models are not fully characterized. Using a different animal model, here, we examined whether and how ErbB kinase inhibitors ameliorate the behavioral endophenotypes relevant to schizophrenia. The animal model for schizophrenia was prepared by exposing neonatal rats to the cytokine EGF. Intraventricular infusion of the ErbB1 inhibitors ZD1839 and PD153035 in these animals ameliorated the deficits in startle response and prepulse inhibition in a dose-dependent manner. The deficits of latent inhibition of fear learning were also alleviated by ZD1839 with its limited effects on body weight gain or locomotor activity. ZD1839 infusion also decreased the busting activity of nigral dopamine (DA) neurons and reduced pallidal DA metabolism, a result that mimics the anti-dopaminergic profile of risperidone and haloperidol in this brain region. ErbB inhibitors appear to have anti-dopaminergic actions to alleviate some of the behavioral deficits common to animal models for schizophrenia.
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Affiliation(s)
- M Mizuno
- Department of Molecular Neurobiology, Brain Research Institute, Niigata University, Niigata, Japan,Institute for Developmental Research, Aichi Human Service Center, Kasugai, Aichi, Japan
| | - H Sotoyama
- Department of Molecular Neurobiology, Brain Research Institute, Niigata University, Niigata, Japan
| | - H Namba
- Department of Molecular Neurobiology, Brain Research Institute, Niigata University, Niigata, Japan
| | - M Shibuya
- Department of Molecular Neurobiology, Brain Research Institute, Niigata University, Niigata, Japan
| | - T Eda
- Department of Molecular Neurobiology, Brain Research Institute, Niigata University, Niigata, Japan
| | - R Wang
- Department of Molecular Neurobiology, Brain Research Institute, Niigata University, Niigata, Japan
| | - T Okubo
- Department of Molecular Neurobiology, Brain Research Institute, Niigata University, Niigata, Japan
| | - K Nagata
- Institute for Developmental Research, Aichi Human Service Center, Kasugai, Aichi, Japan
| | - Y Iwakura
- Department of Molecular Neurobiology, Brain Research Institute, Niigata University, Niigata, Japan
| | - H Nawa
- Department of Molecular Neurobiology, Brain Research Institute, Niigata University, Niigata, Japan,Department of Molecular Biology, Brain Research Institute, Niigata University, Asahimachi-dori 1-757, Niigata 951-8585, Japan. E-mail:
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Batalla A, Bhattacharyya S, Yücel M, Fusar-Poli P, Crippa JA, Nogué S, Torrens M, Pujol J, Farré M, Martin-Santos R. Structural and functional imaging studies in chronic cannabis users: a systematic review of adolescent and adult findings. PLoS One 2013; 8:e55821. [PMID: 23390554 PMCID: PMC3563634 DOI: 10.1371/journal.pone.0055821] [Citation(s) in RCA: 267] [Impact Index Per Article: 24.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2012] [Accepted: 01/02/2013] [Indexed: 12/18/2022] Open
Abstract
Background The growing concern about cannabis use, the most commonly used illicit drug worldwide, has led to a significant increase in the number of human studies using neuroimaging techniques to determine the effect of cannabis on brain structure and function. We conducted a systematic review to assess the evidence of the impact of chronic cannabis use on brain structure and function in adults and adolescents. Methods Papers published until August 2012 were included from EMBASE, Medline, PubMed and LILACS databases following a comprehensive search strategy and pre-determined set of criteria for article selection. Only neuroimaging studies involving chronic cannabis users with a matched control group were considered. Results One hundred and forty-two studies were identified, of which 43 met the established criteria. Eight studies were in adolescent population. Neuroimaging studies provide evidence of morphological brain alterations in both population groups, particularly in the medial temporal and frontal cortices, as well as the cerebellum. These effects may be related to the amount of cannabis exposure. Functional neuroimaging studies suggest different patterns of resting global and brain activity during the performance of several cognitive tasks both in adolescents and adults, which may indicate compensatory effects in response to chronic cannabis exposure. Limitations However, the results pointed out methodological limitations of the work conducted to date and considerable heterogeneity in the findings. Conclusion Chronic cannabis use may alter brain structure and function in adult and adolescent population. Further studies should consider the use of convergent methodology, prospective large samples involving adolescent to adulthood subjects, and data-sharing initiatives.
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Affiliation(s)
- Albert Batalla
- Psychiatry, Institute of Neurosciences, Hospital Clínic, IDIBAPS, CIBERSAM, Barcelona, Spain
- Department of Psychiatry and Clinical Psychobiology, University of Barcelona, Barcelona, Spain
- Melbourne Neuropsychiatry Centre, The University of Melbourne, Melbourne, Victoria, Australia
| | - Sagnik Bhattacharyya
- Department of Psychosis Studies, King’s College London, Institute of Psychiatry, London, United Kingdom
| | - Murat Yücel
- Melbourne Neuropsychiatry Centre, The University of Melbourne, Melbourne, Victoria, Australia
| | - Paolo Fusar-Poli
- Department of Psychosis Studies, King’s College London, Institute of Psychiatry, London, United Kingdom
| | - Jose Alexandre Crippa
- Neuroscience and Cognitive Behavior Department, University of Sao Paulo, Ribeirao Preto, Brazil
- National Science and Technology Institute for Translational Medicine (INCT-TM, CNPq), Ribeirao Preto, Brazil
| | - Santiago Nogué
- Clinical Toxicology Unit, Emergency Department, Hospital Clínic, IDIBAPS, University of Barcelona, Barcelona, Spain
| | - Marta Torrens
- Neuroscience Program, Pharmacology Unit and Drug Addiction Unit, IMIM-INAD-Parc de Salut Mar, Autonomous University of Barcelona, Barcelona, Spain
- Red de Trastornos Adictivos (RETIC), IMIM-INAD-Parc de Salut Mar, Barcelona, Spain
| | - Jesús Pujol
- Institut d’Alta Tecnologia-PRBB, CRC Mar, Hospital del Mar, Barcelona, Spain
| | - Magí Farré
- Neuroscience Program, Pharmacology Unit and Drug Addiction Unit, IMIM-INAD-Parc de Salut Mar, Autonomous University of Barcelona, Barcelona, Spain
- Red de Trastornos Adictivos (RETIC), IMIM-INAD-Parc de Salut Mar, Barcelona, Spain
| | - Rocio Martin-Santos
- Psychiatry, Institute of Neurosciences, Hospital Clínic, IDIBAPS, CIBERSAM, Barcelona, Spain
- Department of Psychiatry and Clinical Psychobiology, University of Barcelona, Barcelona, Spain
- National Science and Technology Institute for Translational Medicine (INCT-TM, CNPq), Ribeirao Preto, Brazil
- * E-mail:
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Lahera G, Freund N, Sáiz-Ruiz J. Asignación de relevancia (salience) y desregulación del sistema dopaminérgico. REVISTA DE PSIQUIATRIA Y SALUD MENTAL 2013; 6:45-51. [DOI: 10.1016/j.rpsm.2012.05.003] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/13/2012] [Revised: 04/30/2012] [Accepted: 05/11/2012] [Indexed: 12/15/2022]
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van der Schaaf ME, van Schouwenburg MR, Geurts DEM, Schellekens AFA, Buitelaar JK, Verkes RJ, Cools R. Establishing the dopamine dependency of human striatal signals during reward and punishment reversal learning. ACTA ACUST UNITED AC 2012. [PMID: 23183711 DOI: 10.1093/cercor/bhs344] [Citation(s) in RCA: 77] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Drugs that alter dopamine transmission have opposite effects on reward and punishment learning. These opposite effects have been suggested to depend on dopamine in the striatum. Here, we establish for the first time the neurochemical specificity of such drug effects, during reward and punishment learning in humans, by adopting a coadministration design. Participants (N = 22) were scanned on 4 occasions using functional magnetic resonance imaging, following intake of placebo, bromocriptine (dopamine-receptor agonist), sulpiride (dopamine-receptor antagonist), or a combination of both drugs. A reversal-learning task was employed, in which both unexpected rewards and punishments signaled reversals. Drug effects were stratified with baseline working memory to take into account individual variations in drug response. Sulpiride induced parallel span-dependent changes on striatal blood oxygen level-dependent (BOLD) signal during unexpected rewards and punishments. These drug effects were found to be partially dopamine-dependent, as they were blocked by coadministration with bromocriptine. In contrast, sulpiride elicited opposite effects on behavioral measures of reward and punishment learning. Moreover, sulpiride-induced increases in striatal BOLD signal during both outcomes were associated with behavioral improvement in reward versus punishment learning. These results provide a strong support for current theories, suggesting that drug effects on reward and punishment learning are mediated via striatal dopamine.
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Affiliation(s)
- Marieke E van der Schaaf
- Donders Institute for Brain Cognition and Behaviour, Radboud University Nijmegen, Nijmegen, the Netherlands and
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Di Forti M, Iyegbe C, Sallis H, Kolliakou A, Falcone MA, Paparelli A, Sirianni M, La Cascia C, Stilo SA, Marques TR, Handley R, Mondelli V, Dazzan P, Pariante C, David AS, Morgan C, Powell J, Murray RM. Confirmation that the AKT1 (rs2494732) genotype influences the risk of psychosis in cannabis users. Biol Psychiatry 2012; 72:811-6. [PMID: 22831980 DOI: 10.1016/j.biopsych.2012.06.020] [Citation(s) in RCA: 158] [Impact Index Per Article: 13.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/29/2012] [Revised: 06/05/2012] [Accepted: 06/06/2012] [Indexed: 11/25/2022]
Abstract
BACKGROUND Cannabis use is associated with an increased risk of psychosis. One study has suggested that genetic variation in the AKT1 gene might influence this effect. METHODS In a case-control study of 489 first-episode psychosis patients and 278 control subjects, we investigated the interaction between variation at the AKT1 rs2494732 single nucleotide polymorphism and cannabis use in increasing the risk of psychosis. RESULTS The rs2494732 locus was not associated with an increased risk of a psychotic disorder, with lifetime cannabis use, or with frequency of use. We did, however, find that the effect of lifetime cannabis use on risk of psychosis was significantly influenced by the rs2494732 locus (likelihood ratio statistic for the interaction = 8.54; p = .014). Carriers of the C/C genotype with a history of cannabis use showed a greater than twofold increased likelihood of a psychotic disorder (odds ratio = 2.18 [95% confidence interval: 1.12, 4.31]) when compared with users who were T/T carriers. Moreover, the interaction between the rs2494732 genotype and frequency of use was also significant at the 5% level (likelihood ratio = 13.39; p = .010). Among daily users, C/C carriers demonstrated a sevenfold increase in the odds of psychosis compared with T/T carriers (odds ratio = 7.23 [95% confidence interval: 1.37, 38.12]). CONCLUSIONS Our findings provide strong support for the initial report that genetic variation at rs2494732 of AKT1 influences the risk of developing a psychotic disorder in cannabis users.
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Affiliation(s)
- Marta Di Forti
- Department of Psychosis Studies, Institute of Psychiatry, Kings College London, London, United Kingdom.
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Jumping to conclusions in psychosis: a faulty appraisal. Schizophr Res 2011; 133:199-204. [PMID: 21907548 DOI: 10.1016/j.schres.2011.08.008] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/02/2011] [Revised: 07/31/2011] [Accepted: 08/15/2011] [Indexed: 11/23/2022]
Abstract
Schizophrenia patients, particularly those with current delusions, show a cognitive bias known as jumping to conclusions, defined as a decision made quickly on the basis of little evidence. The aim of this work was to examine the underlying mechanisms of this cognitive bias by means of the Picture To Decision Task, which allows one to analyse the effect of the context on decisions made. We compared the performance of this task by 42 psychotic patients, 21 siblings of these patients and 77 controls. The results of the current study suggest that, relative to siblings and controls, patients display a general tendency to jump to conclusions, characterised by overestimating the conviction in their choices at the beginning of the decision process and by a lowered threshold for making decisions in ambiguous contexts, where a greater amount of information is required. These results are interpreted in terms of faulty appraisal, which would be the first mechanism responsible for the Jumping To Conclusions bias. Theoretical and clinical implications are discussed.
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Barkus E, Morrison PD, Vuletic D, Dickson JC, Ell PJ, Pilowsky LS, Brenneisen R, Holt DW, Powell J, Kapur S, Murray RM. Does intravenous Δ9-tetrahydrocannabinol increase dopamine release? A SPET study. J Psychopharmacol 2011; 25:1462-8. [PMID: 20851843 DOI: 10.1177/0269881110382465] [Citation(s) in RCA: 74] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Intravenous (IV) Δ9-tetrahydrocannabinol (THC) induces transient psychotic symptoms in healthy subjects and in schizophrenic patients, but the psychotomimetic mechanism is unknown. One possibility is that THC stimulates dopamine (DA) release in the striatum. In this study we tested whether IV THC led to an increase in striatal DA release compared to placebo. We also investigated whether DA release and positive psychotic symptoms were related. Eleven healthy male volunteers completed two 123I-iodobenzamide ([123I]IBZM) single photon emission tomography (SPET) sessions and received IV THC (2.5 mg) or placebo in a randomized counterbalanced order, under double-blind conditions. Analysable data were obtained from nine participants. The Positive and Negative Syndrome Scale (PANSS) was used to rate psychotomimetic effects. Striatal binding index values were calculated using the occipital cortex as a reference region. Both the PANSS positive and general symptoms increased significantly at 30 min following IV THC. There were no significant differences in binding index in the caudate or putamen under THC compared to placebo conditions. Positive psychotic symptoms and DA release were unrelated. THC did not lead to a significant increase in DA release even though the dose was sufficient for participants to have psychotic symptoms. These findings do not support a central role for striatal DA in THC-elicited psychosis.
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Affiliation(s)
- Emma Barkus
- Institute of Psychiatry, Kings College London, London, UK.
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Prins J, Olivier B, Korte SM. Triple reuptake inhibitors for treating subtypes of major depressive disorder: the monoamine hypothesis revisited. Expert Opin Investig Drugs 2011; 20:1107-30. [DOI: 10.1517/13543784.2011.594039] [Citation(s) in RCA: 72] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
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Casadio P, Fernandes C, Murray RM, Di Forti M. Cannabis use in young people: the risk for schizophrenia. Neurosci Biobehav Rev 2011; 35:1779-87. [PMID: 21530584 DOI: 10.1016/j.neubiorev.2011.04.007] [Citation(s) in RCA: 118] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2010] [Revised: 03/09/2011] [Accepted: 04/06/2011] [Indexed: 12/13/2022]
Abstract
Cannabis is one of the most commonly used illicit drugs, and despite the widely held belief that it is a safe drug, its long-term use has potentially harmful consequences. To date, the research on the impact of its use has largely been epidemiological in nature and has consistently found that cannabis use is associated with schizophrenia outcomes later in life, even after controlling for several confounding factors. While the majority of users can continue their use without adverse effects, it is clear from studies of psychosis that some individuals are more vulnerable to its effects than others. In addiction, evidence from both epidemiological and animal studies indicates that cannabis use during adolescence carries particular risk. Further studies are warranted given the increase in the concentration of the main active ingredient (Δ(9)-tetrahydrocannabinol) in street preparations of cannabis and a decreasing age of first-time exposure to cannabis.
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Affiliation(s)
- Paola Casadio
- Mental Health Department, AUSL Ravenna, Via Baliatico 3, Faenza (RA), Italy.
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29
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Effects of cannabis use on age at onset in schizophrenia and bipolar disorder. Schizophr Res 2011; 126:270-6. [PMID: 20674280 DOI: 10.1016/j.schres.2010.07.003] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/19/2009] [Revised: 06/13/2010] [Accepted: 07/09/2010] [Indexed: 01/28/2023]
Abstract
BACKGROUND Cannabis use may decrease age at onset in both schizophrenia and bipolar disorder, given the evidence for substantial phenotypic and genetic overlap between both disorders. METHODS 766 patients, aged 16 to 65 years, were assessed with the Composite International Diagnostic Interview (CIDI) for substance abuse/use. 676 subjects were diagnosed with schizophrenia and 90 subjects with bipolar disorder. The influence of cannabis use on age at onset in both schizophrenia and bipolar disorder was examined using regression analysis. RESULTS Cannabis and other substance use was more frequent in patients with schizophrenia compared to the bipolar group. Both cannabis use and a schizophrenia diagnosis predicted earlier age at onset. There was a significant interaction between cannabis use and diagnosis, cannabis having a greater effect in bipolar patients. Age at onset in users of cannabis was comparable in both diagnostic groups whereas bipolar non-users were significantly older than schizophrenia non-users at onset. CONCLUSION Cannabis use may decrease age at onset in both schizophrenia and bipolar patients and reduce the effect of diagnosis. This is consistent with the view that cannabis use may unmask a pre-existing genetic liability that is partly shared between patients with schizophrenia and bipolar disorder.
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Skinner R, Conlon L, Gibbons D, McDonald C. Cannabis use and non-clinical dimensions of psychosis in university students presenting to primary care. Acta Psychiatr Scand 2011; 123:21-7. [PMID: 20199489 DOI: 10.1111/j.1600-0447.2010.01546.x] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
OBJECTIVE To explore the relationship between cannabis use and self-reported dimensions of psychosis in a population of university students presenting for any reason to primary care. METHOD One thousand and forty-nine students attending the Student Health Unit, National University of Ireland, Galway, completed self-report questionnaires on alcohol and substance misuse, non-clinical dimensions of psychosis [Community Assessment of Psychic Experiences (CAPE)], anxiety and depression [Hospital Anxiety and Depression Scale (HADS)]. Association of cannabis use with psychiatric symptoms was explored whilst controlling for confounds. RESULTS More frequent cannabis use was independently associated with greater intensity of positive, negative and depressive psychotic symptoms. The earlier the age of onset of cannabis use, the more positive psychotic symptoms were reported. CONCLUSION These findings support the hypotheses that cannabis use increases the risk of developing psychotic symptoms and that this risk is further increased in those individuals who use cannabis more heavily and commence it at a younger age.
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Affiliation(s)
- R Skinner
- Department of Psychiatry, National University of Ireland, Galway, Ireland
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31
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Brown AS. The environment and susceptibility to schizophrenia. Prog Neurobiol 2011; 93:23-58. [PMID: 20955757 PMCID: PMC3521525 DOI: 10.1016/j.pneurobio.2010.09.003] [Citation(s) in RCA: 451] [Impact Index Per Article: 34.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2010] [Revised: 09/22/2010] [Accepted: 09/30/2010] [Indexed: 02/07/2023]
Abstract
In the present article the putative role of environmental factors in schizophrenia is reviewed and synthesized. Accumulating evidence from recent studies suggests that environmental exposures may play a more significant role in the etiopathogenesis of this disorder than previously thought. This expanding knowledge base is largely a consequence of refinements in the methodology of epidemiologic studies, including birth cohort investigations, and in preclinical research that has been inspired by the evolving literature on animal models of environmental exposures. This paper is divided into four sections. In the first, the descriptive epidemiology of schizophrenia is reviewed. This includes general studies on incidence, prevalence, and differences in these measures by urban-rural, neighborhood, migrant, and season of birth status, as well as time trends. In the second section, we discuss the contribution of environmental risk factors acting during fetal and perinatal life; these include infections [e.g. rubella, influenza, Toxoplasma gondii (T. gondii), herpes simplex virus type 2 (HSV-2)], nutritional deficiencies (e.g., famine, folic acid, iron, vitamin D), paternal age, fetal/neonatal hypoxic and other obstetric insults and complications, maternal stress and other exposures [e.g. lead, rhesus (Rh) incompatibility, maternal stress]. Other putative neurodevelopmental determinants, including cannabis, socioeconomic status, trauma, and infections during childhood and adolescence are also covered. In the third section, these findings are synthesized and their implications for prevention and uncovering biological mechanisms, including oxidative stress, apoptosis, and inflammation, are discussed. Animal models, including maternal immune activation, have yielded evidence suggesting that these exposures cause brain and behavioral phenotypes that are analogous to findings observed in patients with schizophrenia. In the final section, future studies including new, larger, and more rigorous epidemiologic investigations, and research on translational and clinical neuroscience, gene-environment interactions, epigenetics, developmental trajectories and windows of vulnerability, are elaborated upon. These studies are aimed at confirming observed risk factors, identifying new environmental exposures, elucidating developmental mechanisms, and shedding further light on genes and exposures that may not be identified in the absence of these integrated approaches. The study of environmental factors in schizophrenia may have important implications for the identification of causes and prevention of this disorder, and offers the potential to complement, and refine, existing efforts on explanatory neurodevelopmental models.
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Affiliation(s)
- Alan S Brown
- Department of Psychiatry, College of Physicians and Surgeons of Columbia University, New York State Psychiatric Institute, New York, NY 10032, USA.
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Stilo SA, Murray RM. The epidemiology of schizophrenia: replacing dogma with knowledge. DIALOGUES IN CLINICAL NEUROSCIENCE 2010. [PMID: 20954427 PMCID: PMC3181982 DOI: 10.31887/dcns.2010.12.3/sstilo] [Citation(s) in RCA: 68] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Major advances have been made in our understanding of the epidemiology of schizophrenia. We now know that the disorder is more common and severe in young men, and that the incidence varies geographically and temporally. Risk factors have been elucidated; biological risks include a family history of the disorder, advanced paternal age, obstetric complications, and abuse of drugs such as stimulants and cannabis. In addition, recent research has also identified social risk factors such as being born and brought up in a city, migration, and certain types of childhood adversity such as physical abuse and bullying, as well as social isolation and adverse events in adult life. Current research is focussing on the significance of minor psychotic symptoms in the general population, gene-environmental interaction, and how risk factors impact on pathogenesis; perhaps all risk factors ultimately impact on striatal dopamine as the final common pathway.
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Affiliation(s)
- Simona A Stilo
- Psychosis Clinical Academic Group, Institute of Psychiatry, King's Health Partners, King's College London, UK
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Does dopamine mediate the psychosis-inducing effects of cannabis? A review and integration of findings across disciplines. Schizophr Res 2010; 121:107-17. [PMID: 20580531 DOI: 10.1016/j.schres.2010.05.031] [Citation(s) in RCA: 75] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/14/2010] [Revised: 03/22/2010] [Accepted: 05/16/2010] [Indexed: 11/21/2022]
Abstract
General population epidemiological studies have consistently found that cannabis use increases the risk of developing psychotic disorders in a dose-dependent manner. While the epidemiological signal between cannabis and psychosis has gained considerable attention, the biological mechanism whereby cannabis increases risk for psychosis remains poorly understood. Animal research suggests that delta-9-tetrahydrocannabinol (THC, the main psychoactive component of cannabis) increases dopamine levels in several regions of the brain, including striatal and prefrontal areas. Since dopamine is hypothesized to represent a crucial common final pathway between brain biology and actual experience of psychosis, a focus on dopamine may initially be productive in the examination of the psychotomimetic effects of cannabis. Therefore, this review examines the evidence concerning the interactions between THC, endocannabinoids and dopamine in the cortical as well as subcortical regions implicated in psychosis, and considers possible mechanisms whereby cannabis-induced dopamine dysregulation may give rise to delusions and hallucinations. It is concluded that further study of the mechanisms underlying the link between cannabis and psychosis may be conducted productively from the perspective of progressive developmental sensitization, resulting from gene-environment interactions.
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Abstract
A dysregulation of the mesolimbic dopamine system in schizophrenia patients may lead to aberrant attribution of incentive salience and contribute to the emergence of psychopathological symptoms like delusions. The dopaminergic signal has been conceptualized to represent a prediction error that indicates the difference between received and predicted reward. The incentive salience hypothesis states that dopamine mediates the attribution of "incentive salience" to conditioned cues that predict reward. This hypothesis was initially applied in the context of drug addiction and then transferred to schizophrenic psychosis. It was hypothesized that increased firing (chaotic or stress associated) of dopaminergic neurons in the striatum of schizophrenia patients attributes incentive salience to otherwise irrelevant stimuli. Here, we review recent neuroimaging studies directly addressing this hypothesis. They suggest that neuronal functions associated with dopaminergic signaling, such as the attribution of salience to reward-predicting stimuli and the computation of prediction errors, are indeed altered in schizophrenia patients and that this impairment appears to contribute to delusion formation.
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Affiliation(s)
- Andreas Heinz
- Department of Psychiatry, Charité-Universitätsmedizin Berlin, Charité Campus Mitte, 10117 Berlin, Germany.
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35
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Stilo SA, Murray RM. The epidemiology of schizophrenia: replacing dogma with knowledge. DIALOGUES IN CLINICAL NEUROSCIENCE 2010; 12:305-15. [PMID: 20954427 PMCID: PMC3181982] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 03/24/2024]
Abstract
Major advances have been made in our understanding of the epidemiology of schizophrenia. We now know that the disorder is more common and severe in young men, and that the incidence varies geographically and temporally. Risk factors have been elucidated; biological risks include a family history of the disorder, advanced paternal age, obstetric complications, and abuse of drugs such as stimulants and cannabis. In addition, recent research has also identified social risk factors such as being born and brought up in a city, migration, and certain types of childhood adversity such as physical abuse and bullying, as well as social isolation and adverse events in adult life. Current research is focussing on the significance of minor psychotic symptoms in the general population, gene-environmental interaction, and how risk factors impact on pathogenesis; perhaps all risk factors ultimately impact on striatal dopamine as the final common pathway.
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Affiliation(s)
- Simona A Stilo
- Psychosis Clinical Academic Group, Institute of Psychiatry, King's Health Partners, King's College London, UK
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36
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Siegmann AE. A classification of sociomedical health indicators: perspectives for health administrators and health planners. INTERNATIONAL JOURNAL OF HEALTH SERVICES : PLANNING, ADMINISTRATION, EVALUATION 1976; 6:521-38. [PMID: 955757 PMCID: PMC3004532 DOI: 10.2190/my7u-4bgm-9qfy-n0tn] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
The conceptualization and operationalization of measures of health status are considered. Health indicators are conceived as a subset of social indicators, and therefore, as any social indicator, they are viewed as derivative from social issues. The interrelationships of different frames of reference for defining and measuring health that have accompained three distinct health problem patterns in the United States are viewed from a developmental perspective. Mortality and morbidity rates, the traditional health indicators, by themselves no longer serve to assess health status in developed nations. Their deficiencies as indicators serve as background for a classification schema for sociomedical health status indicators that relates health definition frames of reference, measures of health status, and health problems. The role of a group of health indicators-sociomedical heath indicators-in the current formulation of health status measures is assessed.
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