The prevalence and factors associated with alcohol, cigarette, and marijuana use among adolescents in 25 African countries: evidence from Global School-Based Health Surveys

ObjectivesTo provide first comprehensive estimates of the prevalence of psychoactive substances: alcohol, cigarettes and marijuana and their associated factors among school-going adolescents in 25 African countries, and thereby contribute to the evidence base of substance use in Africa. MethodsWe use the publicly available Global School-Based Health Survey (GSHS) data from 25 African countries collected between 2003 and 2017. We used descriptive statistics to estimate the prevalence of alcohol, cigarette, and marijuana use as well as their dual use among adolescents aged 11 - 16 years. Additionally, we used logistic regressions to model factors associated with the use of each substance, with adjusted odds ratios (ORs) and their 95% confidence intervals (CIs) as the measures of association. ResultsThe prevalence of alcohol use among African adolescents was 10.6% [95% CI = 9.6, 11.8], that for cigarette smoking was 6.9% [95% CI: 6.1, 7.8], and it was 3.8% [95% CI: 3.2, 4.4] for marijuana. The prevalence of dual use of alcohol and cigarettes was 1.5% [95% CI: 1.2, 1.9], that of alcohol and marijuana was 0.9% [95% CI: 0.7, 1.1], and it was 0.8% [95% CI: 0.6, 1.0] for cigarettes and marijuana. The prevalence of cigarette smoking was significantly higher among boys than girls, but that of alcohol and marijuana was insignificant. The use of alcohol, cigarettes, or marijuana was associated with the West African region, higher-income country group, having parents that smoke any tobacco products, being bullied, missing classes without permission, and experiencing sadness and hopelessness in the previous month were positively associated with being a current user of these products. ConclusionsAfrica should invest in data collection on substance use among adolescents who are in and out of school. At both primary and secondary school levels, African countries should develop mentorship and other interventions that fuel positivity and discourage bad practices among students to ultimately reduce substance use. WHAT IS ALREADY KNOWN ON THIS TOPIC[tpltrtarr] At the country level, geography, predominant religion, and income level are risk factors for substance use. [tpltrtarr]At the individual level, home environment, being bullied, feeling sad and hopeless, and having suicidal thoughts are positively associated with students substance use in African primary and secondary schools. WHAT THIS STUDY ADDS[tpltrtarr] In Africa, cigarette smoking among adolescents differs significantly by gender across different age groups. Nonetheless, for alcohol and marijuana use, there is no statistically significant difference by gender across age groups. [tpltrtarr]The common dual use of unhealthy products among adolescents is in the form of alcohol and cigarettes. [tpltrtarr]Staying in the West African region and missing primary or secondary school classes increases the chances of consuming alcohol, cigarettes, and marijuana in both single and dual use. HOW THIS STUDY MIGHT AFFECT RESEARCH, PRACTICE OR POLICY[tpltrtarr] School-based interventions should be developed or further improved to fuel positivity among students and, finally, minimize negative emotions and activities that lead to substance use.