Self-harm, whether attributed to suicidal or non-suicidal motives, is associated with several poor outcomes in young people, including eventual suicide. Much of our understanding of self-harm in young people is based on literature from Europe (particularly, the UK), North America, and Australia. We aimed to synthesise the available evidence on prevalence, the commonly reported self-harm methods, correlates, risk and protective factors, and reasons for self-harm, in adolescents (aged 10–25 years) in sub-Saharan Africa.

We searched MEDLINE, PsycINFO, PubMed, African Journals OnLine, and African Index Medicus for records from 1950 through August 2019, without language restrictions. We supplemented the database searches by searching relevant portals for postgraduate theses, reference harvesting, contacting authors for unpublished studies, and hand searching relevant print sources. We applied narrative synthesis to the evidence.

Seventy-four studies from 18 sub-Saharan African countries met the inclusion criteria. The median lifetime prevalence estimate was 10·3% (interquartile range [IQR] 4·6% – 16·1%); median 12-month prevalence estimate was 16·9% (IQR: 11·5% – 25·5%); median 6-month prevalence estimate was 18·2% (IQR: 12·7% – 21·8%); and the median 1-month prevalence estimate was 3·2% (IQR: 2·5–14·8%). Studies from Western sub-Saharan Africa reported the highest 12-month prevalence estimates (median = 24·3%; IQR = 16·9% – 27·9%). Clinical samples commonly reported overdose, whereas self-cutting was most commonly reported in non-clinical samples. Academic failure, sexual, emotional, and physical abuse, romantic relationship problems, family conflict, depression, and previous self-harm were identified as key correlates of self-harm. No study reported protective factors against self-harm.

Variation in estimates was explained by small sample sizes and variation in definitions and measures used. Exploration of associations, risks and protective factors was based upon concepts and measures derived from high income countries. More detailed and culturally sensitive research is needed to understand the context-specific risks and protective factors for self-harm in adolescents in sub-Saharan Africa.