Cohort Change in the Prevalence of ADHD Among U.S. Adults: Evidence of a Gender-Specific Historical Period Effect

Objective: To document inter- and intra-cohort changes in adult ADHD and examine whether changes vary by gender. Method: We analyze data from the 2007 and 2012 U.S. National Health Interview Survey. Results: The prevalence of ADHD among adults aged 18 to 64 years increased from 3.41% in 2007 to 4.25% in 2012. As expected, patterns of inter- and intra-cohort change varied by gender. At younger ages, inter-cohort gender differences are more distinct due to a spike in prevalence among boys/men born in or after 1980. Consistent with a gender-specific historical period effect, recent intra-cohort increases among women have narrowed the gender gap. Conclusion: The gender gap in the prevalence of ADHD among adults decreased by 31.1% from 2007 to 2012 due to increased prevalence among adult women of all ages. We discuss these results in relation to diagnostic practice, adult health and well-being, data limitations and needs, and directions for future research.