Cannabis and amphetamine use among school-going adolescents in sub-Saharan Africa: a multi-country analysis of prevalence and associated factors

BACKGROUND: Global evidence indicates that early onset of illicit substance use among adolescents and emerging adults is associated with negative mental-health related-outcomes that can persist into adulthood. However, the lack of quality regional data on adolescent illicit substance use and its determinants remains a common barrier to evidence-based policy-making and the development of school-based interventions in Africa. The purpose of our study was to estimate the prevalence and describe the correlates of cannabis and amphetamine use among school-going adolescents in eight sub-Saharan African countries (SSA) – Benin, Ghana, Liberia, Mauritius, Mozambique, Namibia, Seychelles, and Tanzania. METHODS: We analysed 15,553 school-going adolescents that participated in the Global School-based Student Health Survey. A two-stage sampling approach was used to generate a nationally representative sample of school children (grades 7–12) in each of these countries. Students responded to a self-administered structured questionnaire that contained information on sociodemographic factors, family involvement factors, mental health factors, school environment factors and past-month cannabis and life-time amphetamine use. RESULTS: The overall prevalence estimates of past-month cannabis use and lifetime amphetamine use among school-going adolescents in the eight SSA countries was 4.39% (95% CI = 4.08, 4.72) and 3.05% (95% CI = 2.79, 3.34) respectively. In the multivariable logistic regression analysis, demographic characteristics (age and male gender), mental health factors (suicide ideation and attempt), lifestyle factors (cigarette smoking, past-month alcohol use, lifetime drunkenness and leisure-time sedentary behaviour) and school level factors (truancy and bullying victimisation) showed strong associations with increased odds of both past-month cannabis use and lifetime amphetamine use. Social support at school was associated with increased odds for lifetime amphetamine, while parental monitoring decreases the odds for lifetime amphetamine use. It was also observed that parental tobacco use was associated with increased odds of both past-month cannabis use and lifetime amphetamine use. CONCLUSION: The relatively low overall prevalence estimates of past-month cannabis use and lifetime amphetamine use among school-going adolescents in not surprising. However, the identified risk and protective factors associated with cannabis and amphetamine use underscores the need for these eight countries in SSA to develop contextual and multi-sectoral intervention and school-based prevention programmes that could target school-going adolescents who may be at risk of misusing these illicit drugs. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s12888-023-05283-w.