Abstract
The co-occurrence of mental and substance use disorders (SUDs) poses major
public health challenges. Understanding their prevalence and risk factors is critical for
developing targeted interventions.
Aim: To estimate the prevalence of substance use and risk of co-occurring common mental
disorders in three South African provinces (Western Cape, Eastern Cape [EC] and North West
[NW]).
Setting: The study was conducted in three provinces in South Africa (Madibeng district in NW
province, King Sabata Dalindyebo [KSD] in the EC and Khayelitsha in the Western Cape).
Methods: A stratified multistage random household survey was conducted using the 9-item
Patient Health Questionnaire (PHQ-9), 7-item Generalised Anxiety Disorder Assessment
(GAD-7) and Primary Care PTSD Screen (PC-PTSD-5) to assess mental disorders. Alcohol and
substance use were measured with the Alcohol Use Disorders Identification Test (AUDIT) and
Drug Use Disorders Identification Test (DUDIT). Weighted prevalence estimates were
calculated, and Rao–Scott adjusted Chi-square tests accounted for the complex survey design.
Unweighted Chi-square tests explored demographic associations.
Results: Of 1597 participants, 64.9% screened positive for at least one mental disorder. The
prevalence of alcohol use disorder (AUD) was 31.9% and SUD 7.4%. Co-occurrence of AUD
and SUD was 6.3%. Alcohol use disorder was significantly associated with depression, anxiety
and posttraumatic stress disorder (PTSD), whereas SUD (excluding alcohol) showed no
significant associations.
Conclusion: Psychiatric comorbidity was partly associated with substance use. The findings
highlight a substantial burden of co-occurring alcohol use and mental disorders among South
African men, underscoring the need for integrated, trauma-informed primary healthcare services.
Contribution: The study provides population-based evidence to inform service delivery and
policy for under-resourced settings.