Background Adolescent substance use continues to be a growing major public health concern in Africa. Recent studies infer an overall estimated prevalence of 42% among adolescents in sub-Saharan Africa. Unfortunately, this phenomenon is not adequately documented across many settings in the continent despite known negative health and social consequences on affected individuals and their communities. Little is known about the social context of substance use in Africa among this population. Our aim is to conduct a systematic review, exploring the determinants and associated factors that influence adolescent substance use in Africa. Methods We will search the following databases (from January 2000 onwards): PubMed, the Cochrane Library, African Journals Online (AJOL), Google Scholar, ScienceDirect and the World Health Organization (WHO) African Index Medicus. We will include population-based observational studies reporting on determinants and/or risk factors of substance use among adolescents (age 10–19 years) across Africa. Two reviewers will independently screen all citations, full-text articles and abstract data. Potential conflicts will be resolved through discussion. Study methodological quality (or bias) will be appraised using appropriate tools. If feasible, we will conduct a random-effects meta-analysis of data. We plan to conduct a meta-synthesis of qualitative studies where appropriate Discussion This review will describe the range of determinants and associated factors found to significantly influence adolescent substance use in Africa over the last two decades. Documenting this evidence is important as it can potentially inform comprehensive interventions and treatment programmes that are targeted at adolescents and their parents in these settings. Systematic review registration PROSPERO CRD42020190158

Abstract Background: Substance use among adolescents continues to be a growing major public health concern in Africa. Recent studies infer an overall estimated prevalence of 42% among adolescents in sub-Saharan Africa. Unfortunately, this phenomenon is not adequately documented across many settings in the continent despite known negative health and social consequences on affected individuals and their communities. Little is known about the social context of substance use in Africa among this population. Our aim is to conduct a systematic review to explore determinants and associated factors that influence adolescent substance use and the effects of substance use in sub-Saharan Africa.Methods: The Cochrane Library, PubMed, EMBASE, African Journals Online, Google Scholar, Scopus, Global Health, PsychINFO, Web of Science, and the World Health Organization (WHO) regional databases will be searched for population-based observational studies reporting on the prevalence of substance use of adolescents (age 10 - 19 years) across Africa. Search dates will be from January 2000 to December 2019. Data will be extracted from eligible publications, using a data extraction tool developed for this study. A random effects meta-analysis will be conducted to pool determinants and effects (at 95% confidence interval) of estimated substance abuse among adolescents. Alternative visual and statistical approaches will be adopted instead of traditional meta-analytic approaches where necessary.Discussion: This systematic review will describe the range of determinants and associated factors that have been found to significantly influence substance use in this population group over the last two decades. Additionally, the review will also describe the possible effects of substance use among adolescents. Documenting this evidence is important as it can potentially be used to inform comprehensive interventions and treatment programmes that are targeted at adolescents and their parents in these settings.Systematic review registration: registered on PROSPERO; registration number tbc.