@article{841eaf7cf2d34d0a9e20159d14fbe919,
title = "Influence of cannabis use on incidence of psychosis in people at clinical high risk",
abstract = "Aims: Evidence for case–control studies suggests that cannabis use is a risk factor for the development of psychosis. However, there have been limited prospective studies and the direction of this association remains controversial. The primary aim of the present study was to examine the association between cannabis use and the incidence of psychotic disorders in people at clinical high risk of psychosis. Secondary aims were to assess associations between cannabis use and the persistence of psychotic symptoms, and with functional outcome. Methods: Current and previous cannabis use were assessed in individuals at clinical high risk of psychosis (n = 334) and healthy controls (n = 67), using a modified version of the Cannabis Experience Questionnaire. Participants were assessed at baseline and followed up for 2 years. Transition to psychosis and persistence of psychotic symptoms were assessed using the Comprehensive Assessment of At-Risk Mental States criteria. Level of functioning at follow up was assessed using the Global Assessment of Functioning disability scale. Results: During follow up, 16.2% of the clinical high-risk sample developed psychosis. Of those who did not become psychotic, 51.4% had persistent symptoms and 48.6% were in remission. There was no significant association between any measure of cannabis use at baseline and either transition to psychosis, the persistence of symptoms, or functional outcome. Conclusions: These findings contrast with epidemiological data that suggest that cannabis use increases the risk of psychotic disorder.",
keywords = "THC, clinical high-risk, longitudinal, psychotic disorders, substance use",
author = "Chester, {Lucy A.} and Valmaggia, {Lucia R.} and Kempton, {Matthew J.} and Edward Chesney and Dominic Oliver and Hedges, {Emily P.} and Elise Klatsa and Daniel Stahl and {van der Gaag}, Mark and {de Haan}, Lieuwe and Barnaby Nelson and Patrick McGorry and Amminger, {G. Paul} and Anita Riecher-R{\"o}ssler and Erich Studerus and Rodrigo Bressan and Neus Barrantes-Vidal and Marie-Odile Krebs and Birte Glenth{\o}j and Merete Nordentoft and Stephan Ruhrmann and Gabriele Sachs and Philip McGuire and {EU-GEI High Risk Study Group} and Philip McGuire and Valmaggia, {Lucia R.} and Kempton, {Matthew J.} and Maria Calem and Stefania Tognin and Gemma Modinos and {van der Gaag}, Mark and Eva Velthorst and Kraan, {Tamar C.} and {van Dam}, {Daniella S.} and Nadine Burger and Barnaby Nelson and Patrick McGorry and Amminger, {G. Paul} and Christos Pantelis and Athena Politis and Joanne Goodall and Anita Riecher-R{\"o}ssler and Stefan Borgwardt and Erich Studerus and Rodrigo Bressan and Ary Gadelha and Elisa Brietzke and Graccielle Asevedo and Elson Asevedo and Andre Zugman and Neus Barrantes-Vidal",
note = "Funding Information: The European Network of National Schizophrenia Networks Studying Gene–Environment Interactions (EU‐GEI) Project is funded by grant agreement HEALTH‐F2‐2010‐241909 (Project EU‐GEI) from the European Community's Seventh Framework Programme. Additional support was provided by the NIHR Maudsley Biomedical Research Centre, an NIHR Maudsley Biomedical Research Centre PhD studentship to LC and a Medical Research Council Fellowship to MK (grant MR/J008915/1). Many thanks to the EU‐GEI High Risk Study Group for designing and implementing the study. EU‐GEI collaborators and their affiliations are listed in the Supplementary Materials, including all non‐author contributors. Publisher Copyright: {\textcopyright} 2023 The Authors. Psychiatry and Clinical Neurosciences published by John Wiley & Sons Australia, Ltd on behalf of Japanese Society of Psychiatry and Neurology.",
year = "2023",
month = sep,
day = "1",
doi = "https://doi.org/10.1111/pcn.13555",
language = "English",
volume = "77",
pages = "469--477",
journal = "Psychiatry and clinical neurosciences",
issn = "1323-1316",
publisher = "Wiley-Blackwell Publishing Ltd",
number = "9",
}