The International Journal of Neuropsychopharmacology
September 9, 2026
Marta Di Forti, Isabelle Austin-Zimmerman, Edoardo Spinazzola et al.
Abstract Background Epidemiological data have consistently shown an association between heavy cannabis use and increased risk of psychotic disorders. Nevertheless, not all cannabis users develop the illness. Evidence from other substance of abuse such as Alcohol suggest how genetic differences in enzymes involved in its metabolism influence individual response to the drug. No studies to data...
Biological Psychiatry Global Open Science
May 13, 2026
Isabelle Austin-Zimmerman, Qiang Li, E. Johnson et al.
Background Cannabis use is associated with increased risk of psychotic disorders, but the underlying biological mechanisms remain unclear. We used genetic data to investigate the molecular pathways contributing to the association between cannabis use disorder (CUD) and psychosis. Methods We conducted a cross-disorder meta-analysis of genome-wide association studies (GWASs) on schizophrenia and...
Psychological Medicine
August 8, 2025
Giulia Trotta, Edoardo Spinazzola, Hannah Degen et al.
4 citations
Childhood trauma is a well-established risk factor for psychosis, paranoia, and substance use, with cannabis being a modifiable environmental factor that exacerbates these vulnerabilities. This study examines the interplay between childhood trauma, cannabis use, and paranoia using standard tetrahydrocannabinol (THC) units as a comprehensive measure of cannabis exposure. Data were derived from...
Cambridge University Press eBooks
May 12, 2023
Edoardo Spinazzola, Marta Di Forti, Robin Murray
The fact that not all cannabis users will develop psychosis suggests that cannabis may exert its causal role only in pre-disposed individuals. However, since the number of people who use cannabis worldwide is so high, those who will eventually develop psychosis, whilst still a minority, represent a large number. The evidence indicates that different patterns of cannabis use have a different...
Psychological Medicine
May 4, 2023
Giulia Trotta, Victoria Rodriguez, Diego Quattrone et al.
Abstract Background Childhood adversity and cannabis use are considered independent risk factors for psychosis, but whether different patterns of cannabis use may be acting as mediator between adversity and psychotic disorders has not yet been explored. The aim of this study is to examine whether cannabis use mediates the relationship between childhood adversity and psychosis. Methods Data were...
Psychological Medicine
May 2, 2023
Edoardo Spinazzola, Diego Quattrone, Victoria Rodriguez et al.
Abstract Background While cannabis use is a well-established risk factor for psychosis, little is known about any association between reasons for first using cannabis (RFUC) and later patterns of use and risk of psychosis. Methods We used data from 11 sites of the multicentre European Gene-Environment Interaction (EU-GEI) case–control study. 558 first-episode psychosis patients (FEPp) and 567...
The World Journal of Biological Psychiatry
March 22, 2022
Deepak C. D’Souza, Marta DiForti, Suhas Ganesh et al.
Abstract Objectives The liberalisation of cannabis laws, the increasing availability and potency of cannabis has renewed concern about the risk of psychosis with cannabis. Methods The objective of the WFSBP task force was to review the literature about this relationship. Results Converging lines of evidence suggest that exposure to cannabis increases the risk for psychoses ranging from...
Translational Psychiatry
August 10, 2021
Diego Quattrone, Ulrich Reininghaus, Anne Richards et al.
Diagnostic categories do not completely reflect the heterogeneous expression of psychosis. Using data from the EU-GEI study, we evaluated the impact of schizophrenia polygenic risk score (SZ-PRS) and patterns of cannabis use on the transdiagnostic expression of psychosis. We analysed first-episode psychosis patients (FEP) and controls, generating transdiagnostic dimensions of psychotic symptoms...