Background: Cannabis use among individuals with schizophrenia in the Democratic Republic of Congo, although common, remains poorly documented. This study explores the main sociodemographic and clinical factors associated with cannabis use among patients with schizophrenia treated at the Neuro-Psycho-Pathological Center of the University of Kinshasa.

Methods: A cross-sectional analytical study was conducted. Sociodemographic and clinical data were collected using a structured questionnaire. The Diagnostic and Statistical Manual of Mental Disorders (DSM-5) and the International Classification of Diseases (ICD-10) were used for the diagnosis of use disorders and the classification of schizophrenia subtypes. Statistical analysis included multivariate logistic regression to identify significant associations.

Results: Paranoid schizophrenia (OR = 2.013; CI [1.098–6.170]; p = 0.007) and schizoaffective disorder (OR = 2.305; CI [1.168–3.033]; p = 0.008) were the main clinical forms associated with cannabis use disorder. Male gender, younger age, lower education level, and single marital status were also significantly associated with cannabis use among patients with schizophrenia.

Discussion: Paranoid schizophrenia and schizoaffective disorder appear to play a decisive role in the development of cannabis use disorder among individuals with schizophrenia. Sociodemographic variables such as male gender and low education further increase vulnerability.

Conclusion: Paranoid schizophrenia and schizoaffective disorder are strongly associated with the development of cannabis use disorder in patients with schizophrenia in Kinshasa. These findings highlight the need for integrated therapeutic approaches combining schizophrenia and addiction management in low-resource settings.