Cannabis Use Among People With Psychosis Varied Dramatically Across Four African Countries | Research

The takeaway

Substance use patterns among people with psychotic disorders differed significantly across South Africa, Ethiopia, Kenya, and Uganda, with males showing consistently higher cannabis, tobacco, and alcohol use.

Global mental health researchers, African psychiatrists, substance use policy researchers

Cannabis use among people with psychosis varied significantly across South Africa, Ethiopia, Kenya, and Uganda

What the researchers found

Significant variations in cannabis consumption were observed across the four African countries studied. Males had consistently higher odds of alcohol, tobacco, and khat consumption compared to females. People with bipolar disorder had higher odds of alcohol use than those with schizophrenia. Unlike US studies, education level was not significantly associated with substance use frequency for most substances.

Why it matters

Most substance use research in psychosis comes from Western countries. This large multi-country African study reveals that patterns differ substantially from US and European populations, suggesting that interventions cannot simply be imported from Western settings.

The numbers in context

Four countries: South Africa, Ethiopia, Kenya, Uganda; males higher odds for alcohol, tobacco, khat; bipolar disorder higher alcohol than schizophrenia; significant country-level variation in cannabis; education not significantly associated with most substance use (unlike US data); part of a 42,000+ participant genetics project

How the study worked

Data from the Neuropsychiatric Genetics of African Populations-Psychosis project, a large case-control study. Substance use assessed with ASSIST v3. Ordinal regression examined frequency of alcohol, tobacco, cannabis, and khat use across sex, education, and country in people with bipolar disorder and schizophrenia.

What this study cannot tell us

Cross-sectional design, substance use measured by frequency not quantity, ASSIST may not capture cultural patterns of use, four countries cannot represent all of Africa, possible reporting bias in psychiatric populations, selection effects in case-control recruitment

How to read the evidence

Large multi-country sample from major genetics project with validated measures; strong descriptive data for under-studied populations

When this study was published

Published 2025

The bigger picture

The finding that education-substance use relationships differ between Africa and the US challenges the assumption that sociodemographic risk factors for substance use are universal. Effective prevention in African psychiatric populations requires locally informed approaches.

Questions still open

What drives the country-level variation in cannabis use among people with psychosis? Why does education not predict substance use in these African populations? Do these patterns change with urbanization and economic development?

Common questions

Do people with psychosis in Africa use cannabis differently than in Western countries?

Yes. This study found significant variation across four African countries, and unlike US studies, education level was not associated with substance use frequency, suggesting distinct sociodemographic patterns.

Who is most likely to use cannabis among African psychiatric patients?

Males had consistently higher substance use across all four countries. Cannabis use patterns varied significantly by country, suggesting regional and cultural factors play important roles.

Read the original research

Sociodemographic influences on substance use in psychosis in an African cohort.

Schizophrenia research, 281, 157-163

View on PubMed ↗Publisher’s paper ↗

Citation

Campbell, Megan L; Odokonyero, Raymond; Akena, Dickens; Alemayehu, Melkam; Atwoli, Lukoye; Chibnik, Lori B; Gelaye, Bizu; Gichuru, Stella; Kariuki, Symon M; Koenen, Karestan C; Kwobah, Edith; Kyebuzibwa, Joseph; Mwema, Rehema M; Newton, Charles R J C; Post, Kristianna; Pretorius, Adele; Stevenson, Anne; Stroud, Rocky E; Teferra, Solomon; Zingela, Zukiswa; Stein, Dan J; Hook, Kimberly. (2025). Sociodemographic influences on substance use in psychosis in an African cohort.. Schizophrenia research, 281, 157-163. https://doi.org/10.1016/j.schres.2025.04.012