Attention-deficit/hyperactivity disorder in Mozambique: an epidemiological investigation in a primary school sample

To evaluate the prevalence of attention-deficit/hyperactivity disorder (ADHD), comorbidity rates with disruptive behavior disorders and main negative outcomes in primary school students in Nampula, Mozambique.

We selected a random sample of 748 students for ADHD screening from a population of around 43,000 primary school students. The Swanson, Nolan, and Pelham Rating Scale version IV was applied to both parents and teachers. All students who screened positive (n=76) and a propensity score-matched random subset of students who screened negative (n=76) were assessed by a child psychiatrist.

The prevalence of ADHD was estimated at 13.4% (95%CI 11.5-19.2), and 30.6% of those with ADHD presented comorbid disruptive behavior disorders. Students with ADHD (n=36) had significantly higher rates of both substance use (alcohol, marijuana) (p < 0.001), and school failures than controls (n=96; p < 0.001). Comorbidity between ADHD and disruptive behavior disorders increased the chance of substance use (p < 0.001). Secondary analyses with more restrictive ADHD diagnostic criteria revealed a lower prevalence rate (6.7%; 95%CI 5.2-12.9) with similar patterns of associated factors and negative outcomes.

Our findings demonstrated that ADHD is a prevalent mental disorder in Mozambique, and it is associated with similar comorbid profiles, predisposing factors, and negative outcomes, as in other cultures.