Epidemiology of attention-deficit/hyperactivity disorder (ADHD) in children and adolescents in Africa: a systematic review and meta-analysis

BACKGROUND: Attention-deficit/hyperactivity disorder (ADHD) is the most common neurodevelopmental disorders in childhood and adolescence, affecting 2.2 to 17.8% of all school-aged children and adolescents. ADHD in children has been associated with a wide range of developmental deficits including limitations of learning or control of executive functions as well as global impairments of social skills. However, no review has been conducted to report the consolidated magnitude of ADHD in children and adolescents in Africa. Therefore, this systematic review and meta-analysis aimed to estimate the prevalence of ADHD in Africa. METHODS: Following the PRISMA guideline, we systematically reviewed and meta-analyzed studies that investigated the prevalence of ADHD in Africa from three electronic databases (PubMed, Embase, and Scopus). We also looked at the reference lists of included studies to include other relevant studies. Subgroup and sensitivity analysis was carried out based on the study setting, tools used to measure ADHD, sex of participants, and the subtype of ADHD. Heterogeneity across the studies was evaluated using Cochran's Q- and the I(2)-test. We assessed potential publication bias using Egger's test and visual inspection of the symmetry in funnel plots. RESULTS: In the present meta-analysis, 7452 articles were initially identified and evaluated. Of these, 12 studies that met the inclusion criteria were included in the final analysis. The pooled prevalence of ADHD in children and adolescents in Africa was 7.47% (95% CI 60–9.26). The prevalence of ADHD was apparently greater in boys (10.60%) than in girls (5.28%) with a male:female ratio of 2.01:1. In our subgroup analysis, the predominantly inattentive type (ADHD-I) was found to be the most common subtype of ADHD, followed by hyperactive–impulsive type (ADHD-HI) and the combined type (ADHD-C) with the prevalence of 2.95%, 2.77%, and 2.44% respectively. The predominantly inattentive type (ADHD-I) was the most common type of ADHD in both boys (4.05%) and girls (2.21%). The funnel plot and Egger's regression tests provided no evidence of substantial publication bias in the prevalence of ADHD. CONCLUSION: Our systematic review suggested a higher prevalence of ADHD (7.47%) in children and adolescents in Africa, indicating that ADHD is a serious public health problem in children and adolescents in Africa. The prevalence of ADHD was considerably greater in males than in females. The predominantly inattentive type (ADHD-I) was the most common type of ADHD in both males and females. Greater attention needs to be paid to the prevention and treatment of ADHD.