ADHD in Adults: A Systematic Review and Meta-Analysis of Prevalence Studies in Outpatient Psychiatric Clinics.

Systematic review and meta-analysis to estimate the pooled prevalence of ADHD in adult attendees of outpatient mental health clinics and to investigate factors influencing prevalence rates. The following were extracted: demographics, design of the study (screening only or two-phase), scales/criteria for diagnosis of ADHD, number of ADHD, and non-ADHD participants. The pooled prevalence of ADHD from screening studies ( Meta-analysis shows high rates of adult ADHD among psychiatric outpatient clinics. Applying DSM-5 criteria increased prevalence rates. More methodologically robust studies, using two-stage design, need to be conducted to help assist in service planning.