Lucy Wanjiku Murage, Michael Kihara, Stella Nyagwencha
Attention-Deficit/Hyperactivity Disorder (ADHD) commonly persists into adulthood and frequently co-occurs with Substance Use Disorders (SUDs), yet evidence from low- and middle-income countries remains limited. This study examined the prevalence and symptom presentations of ASRS-based probable Adult ADHD among adults receiving treatment for SUDs in selected rehabilitation centres in Nairobi, Kenya. A quantitative descriptive cross-sectional study was conducted among 322 adults recruited through total enumeration from six rehabilitation centres. Adult ADHD symptoms were assessed using the Adult ADHD Self-Report Scale (ASRS v1.1). Overall, 90 of the 322 participants (28.0%) met the criteria for ASRS-based probable Adult ADHD. Among respondents classified as having ASRS-based probable ADHD, the combined presentation was the most prevalent (58.9%), followed by the predominantly inattentive (26.7%) and predominantly hyperactive–impulsive (14.4%) presentations. These findings indicate that ASRS-based probable Adult ADHD was identified in more than one-quarter of adults receiving treatment for SUDs and that the combined presentation predominated among screen-positive respondents. The findings contribute to the limited evidence on ASRS-based probable Adult ADHD among treatment-seeking adults in Sub-Saharan Africa and may inform future research and review of ADHD screening practices in comparable rehabilitation settings.