Gender ratios of administrative prevalence and incidence of attention-deficit/hyperactivity disorder (ADHD) across the lifespan: A nationwide population-based study in Taiwan.

To verify the hypothesis that there is different gender ratio of attention-deficit/hyperactivity disorder (ADHD) among adults compared to children and adolescents in the clinical setting among Asian population. The nationwide population-based database containing data on enrollees in the National Health Insurance program in Taiwan during 2000-2007 was used in this study, and we investigated the lifetime gender ratios of administrative prevalence and incidence in healthcare-seeking ADHD patients (n=228,029). The male-to-female ratios of diagnosed incidence and prevalence of child/adolescent ADHD (age <20 years) ranged from 3.39 to 4.07 and 3.87-4.31, respectively. The male-to-female ratios of diagnosed incidence and prevalence of ADHD in the adult group (age 20-65 years) ranged from 0.24 to 0.76 and 0.35-0.98, respectively. In conclusion, there was substantially increased female-to-male ratio in adults ADHD compared to children and adolescents in the clinical setting. Further researches on the management and mechanism are needed.