Sex Differences in ADHD: Review and Priorities for Future Research

Purpose of review: In childhood, attention-deficit/hyperactivity disorder (ADHD) is diagnosed three to 16 times more frequently in males compared to females, yet in adulthood, nearly equivalent numbers of males and females are diagnosed with ADHD. Relatively few studies have prioritized examination of sex differences in ADHD even though sex differences may have critical implications for the identification and treatment of ADHD in females and males. This review highlights current research on sex differences in ADHD across the lifespan that has emerged from cross-sectional and prospective longitudinal studies of youth, adult-ascertained samples, and registry studies. Recent findings: Accumulating research suggests that both males and females with ADHD experience widespread impairment across the lifespan. Some evidence of sex differences emerged, although effects have generally been modest in size. Summary: Continued research that includes females and males with ADHD is needed to clarify the nature of sex differences in ADHD. Research that focuses on equitable identification of ADHD in males and females, disentangles the effects of sex and gender, probes underlying mechanisms of sex differences, and addresses the clinical impact of sex differences in ADHD must be prioritized.