International Journal of Neuropsychopharmacology
September 9, 2026
M Di Forti, I Austin-Zimmerman, E 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...
International Journal of Neuropsychopharmacology
September 1, 2026
Z. Li, D. Mukherjee, E. Dempster et al.
Abstract Background Adolescent cannabis use is associated with an increased risk of psychosis, yet the underlying molecular mechanisms remain poorly understood. Emerging evidence also pointed to genetic liability shaping individual risk of cannabis-induced psychosis. The neuregulin–ErbB4 signalling pathway, implicated in schizophrenia-related neurodevelopment, may modulate individual...
Biological Psychiatry Global Open Science
May 13, 2026
I. 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...
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
December 1, 2022
Fabiana Corsi-Zuelli, Leonardo Marques, Daiane Leite Da Roza et al.
Cannabis consumption is a modifiable risk factor associated with psychosis, but not all cannabis users develop psychosis. Animal studies suggest that an antecedent active immune system interacts with subsequent cannabis exposure and moderates the cannabis-psychosis association, supporting the two-hit hypothesis. The clinical investigations are few, and it is unclear if the immune system is a...
Translational Psychiatry
August 10, 2021
Diego Quattrone, Ulrich Reininghaus, A. 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...
Irish Journal of Psychological Medicine
May 27, 2021
Lydia Johnson-Ferguson, Marta Di Forti
8 citations
Cannabis is one of the most widely used recreational drugs among people with clinical psychosis, after nicotine and alcohol. There has been a debate in psychiatry about whether or not we can infer a cause-and-effect relationship between the use of cannabis and psychotic disorders. In this editorial, we first present and critically discuss the evidence to date of the association between heavy...
Translational Psychiatry
May 12, 2020
Chandni Hindocha, Diego Quattrone, Tom P. Freeman et al.
Epidemiological and biological evidence support the association between heavy cannabis use and psychosis. However, it is unclear which cannabis users are susceptible to its psychotogenic effect. Therefore, understanding genetic factors contributing to this relationship might prove an important strategy to identify the mechanisms underlying cannabis-associated psychotic experiences. We aimed to...
Psychological Medicine
March 18, 2020
Diego Quattrone, Laura Ferraro, Giada Tripoli et al.
89 citations
Abstract Background Daily use of high-potency cannabis has been reported to carry a high risk for developing a psychotic disorder. However, the evidence is mixed on whether any pattern of cannabis use is associated with a particular symptomatology in first-episode psychosis (FEP) patients. Method We analysed data from 901 FEP patients and 1235 controls recruited across six countries, as part of...
Frontiers in Behavioral Neuroscience
2011
Alessandra Paparelli, Marta Di Forti, Paul D. Morrison et al.
217 citations
The prevalent view today is that schizophrenia is a syndrome rather than a specific disease. Liability to schizophrenia is highly heritable. It appears that multiple genetic and environmental factors operate together to push individuals over a threshold into expressing the characteristic clinical picture. One environmental factor which has been curiously neglected is the evidence that certain...
The British Journal of Psychiatry
November 30, 2009
Marta Di Forti, Craig Morgan, Paola Dazzan et al.
577 citations
BACKGROUND: People who use cannabis have an increased risk of psychosis, an effect attributed to the active ingredient Delta 9-tetrahydrocannabinol (Delta 9-THC). There has recently been concern over an increase in the concentration of Delta 9-THC in the cannabis available in many countries. AIMS: To investigate whether people with a first episode of psychosis were particularly likely to use...
Schizophrenia Bulletin
November 1, 2008
Cécile Henquet, Marta Di Forti, Paul D. Morrison et al.
Cannabis use is considered a contributory cause of schizophrenia and psychotic illness. However, only a small proportion of cannabis users develop psychosis. This can partly be explained by the amount and duration of the consumption of cannabis and by its strength but also by the age at which individuals are first exposed to cannabis. Genetic factors, in particular, are likely to play a role in...