Schizophrenia associated with cannabis use in the psychiatry département in Toamasina, Madagascar: Clinical and sociodemographic characteristics
HH Ratobimanankasina, HA Razakandrainy, JDC Rasolonjatovo, BH Rajaonarison, A Raharivelo
International Journal of Psychiatry Research May 1, 2026 DOI: 10.33545/26648962.2026.v8.i5a.140 (opens in new tab)
Study at a glance
AI-extracted from the abstract| Characteristics | Descriptive, longitudinal, retro-prospective, single-center study Peer reviewed |
|---|---|
| Sample size | 55 |
| Population | Patients with schizophrenia and reported cannabis use managed in full hospitalization or outpatient consultation at the Psychiatry Department of the Analankininina University Hospital Center of Toamasina, Madagascar, between 1 June 2022 and 31 December 2023 |
| Interventions | supportive psychotherapy classical antipsychotics |
| Duration | Managed between 1 June 2022 and 31 December 2023; outcomes assessed at 3 months |
| Topics | Cannabis |
| Key findings | Among 55 patients with schizophrenia who reported cannabis use, the group was predominantly young men with positive psychotic symptoms and behavioral dyscontrol; cannabis use preceded the psychotic disorder in 87.27%. At three months, 40.00% had improved, 32.73% had relapsed, and 27.27% were lost to follow-up, which the authors describe as unstable short-term outcomes. |
Abstract
Background: Comorbidity between schizophrenia and cannabis use is associated with greater clinical complexity, behavioural dyscontrol, repeated admissions, and major social consequences. Published hospital data from Madagascar remain limited.
Aim: To describe the epidemiological and clinical profile of patients with schizophrenia associated with reported cannabis use in the Psychiatry Department of the Analankininina University Hospital Center of Toamasina.
Methods: We conducted a descriptive, longitudinal, retro-prospective, single-center study including patients managed in full hospitalization or outpatient consultation between 1 June 2022 and 31 December 2023. Diagnosis of schizophrenia was established clinically by using ICD-10 criteria applied in routine care. Patients were included when they met the diagnostic criteria for schizophrenia and reported cannabis use.
Results: Among 1, 958 registered patients, 55 met the study criteria, corresponding to a hospital-based proportion of 2.81%. Mean age was 27.67 years (range 16-66), 94.55% were male, 61.82% were single, 69.09% had secondary education, and 43.64% were unemployed. Aggressive behaviour was the leading admission reason (50.91%). Childhood psychological trauma was reported in 38.18%, personal history of psychosis in 65.45%, and acute onset in 76.36%. Persecutory delusions (72.73%), aggression (70.91%), and auditory hallucinations (50.91%) predominated. Reported cannabis use preceded psychotic disorder in 87.27% of cases. All patients received supportive psychotherapy and classical antipsychotics; 40.00% improved at 3 months, 32.73% relapsed, and 27.27% were lost to follow-up.
Conclusion: In this hospital cohort, comorbid schizophrenia and reported cannabis use concerned predominantly young men and was marked by positive psychotic symptoms, behavioural dyscontrol, and unstable short-term outcomes. Early detection, psychoeducation, adherence support, and continuity of psychiatric follow-up should be strengthened.
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 |