Effects of persistent cannabis use on depression, psychosis, and suicidality following cannabis‐induced psychosis: A longitudinal study
Valerio Ricci, Domenico de Berardis, Giovanni Martinotti, Giuseppe Maina
American Journal on Addictions September 1, 2025 DOI: 10.1111/ajad.70048 (opens in new tab)
Study at a glance
AI-extracted from the abstract| Characteristics | Observational cohort Longitudinal Peer reviewed |
|---|---|
| Sample size | 44 |
| Population | Patients aged 16-50 years with cannabis-induced first-episode psychosis from psychiatric inpatient facilities in northern Italy |
| Duration | 9-month follow-up |
| Topics | Cannabis Depression |
| Key findings | Continued cannabis use after first-episode psychosis is associated with persistently higher depression and suicidality scores and slower recovery of positive psychotic symptoms compared to cannabis cessation. |
Abstract
AbstractBackground and ObjectivesCannabis use is associated with psychotic disorder onset and exacerbation. This study examines how continued cannabis use affects depressive symptoms, psychotic symptoms, and suicidal behaviors following cannabis‐induced first‐episode psychosis (FEP).MethodsSixty‐five participants (aged 16–50 years) with FEP were recruited from psychiatric inpatient facilities in northern Italy. Participants were categorized into two groups: non‐cannabis users (NCU) and cannabis users (CU), based on substance use during the 9‐month follow‐up. Twenty‐one participants (32.3%) were lost to follow‐up, with a final sample of 44 subjects (NCU = 22, CU = 22). Assessments were conducted at baseline, 3 months, and 9 months using PANSS, CDSS, SSI, and GAF scales).ResultsCU exhibited persistently higher depression (CDSS) and suicidality (SSI) scores than NCU throughout follow‐up, with significant differences at both 3 months (CDSS: p = .000006; SSI: p < .001) and 9 months (CDSS: p = .0000001; SSI: p < .001). Positive psychotic symptoms improved in both groups, though CU showed slower recovery and higher relapse rates (59.9% vs. 18.8%). PANSS positive subscale scores remained significantly higher in CU at 3 months (p = .001) and 9 months (p < .0002). GAF scores improved significantly only in NCU (p = .024 at 9 months).Discussion and ConclusionsContinued cannabis use adversely affects depressive and psychotic symptoms and suicidality in FEP patients, while cannabis cessation is associated with improved clinical outcomes.Scientific SignificanceThis study tracks depressive symptoms, suicidality, and psychotic manifestations in cannabis‐induced FEP, demonstrating that continued use is associated with treatment‐resistant depressive symptoms even when psychotic symptoms improve, highlighting the need for integrated clinical approaches.
Comparable studies
Other observational and cohort studies on cannabis, most cited first.
| Study | Year | Design | Participants |
|---|---|---|---|
| High-potency cannabis and the risk of psychosis People with first episode of psychosis and healthy controls from the local population | 2009 | Case-control study | n = 454 |
| Ayahuasca-Assisted Therapy for Addiction: Results from a Preliminary Observational Study in Canada Rural aboriginal population | 2013 | Observational study | |
| Impaired cognitive performance in drug free users of recreational ecstasy (MDMA) Otherwise healthy young people | 2000 | Observational | |
| Continued cannabis use and risk of incidence and persistence of psychotic symptoms: 10 year follow-up cohort study Individuals from the general population in Germany aged 14-24 at baseline | 2011 | Observational cohort | n = 1,923 |
| Cannabis-induced psychosis and subsequent schizophrenia-spectrum disorders: follow-up study of 535 incident cases Patients treated for cannabis-induced psychotic symptoms in Denmark between 1994 and... | 2005 | Observational cohort | n = 535 |
Citations in the library
Cited by 3
- Sex-specific vulnerabilities in cannabis-induced psychosis: A scoping review. Asian Journal of Psychiatry July 8, 2026
- From substance-induced psychosis to schizophrenia: Predictors of treatment response and transition to chronic psychotic illness-A systematic review. Schizophrenia Research March 24, 2026
- Acute and long-term psychiatric consequences of synthetic cannabinoids and related novel psychoactive substances: A systematic review. Psychiatry Research February 1, 2026
Cites 16
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