Multiple Origins of Sex Differences in Brain

Abstract

Attention deficit hyperactivity disorder (ADHD) is considered one of the most prevalent psychiatric disorders; by some criteria it affects about 10 % of school-aged children and nearly 5 % of adults. The current diagnostic criteria evolved from the core features (attention deficits and behavioral excesses) described over 100 years ago by Still (1902). More males than females are recognized and treated for ADHD, but the observed sex difference is smaller in adults than children. To address the topic of the multiple origins of sex differences in ADHD, we discuss some factors that influence ADHD-related sex differences: (1) secular trends that have recently increased the recognition and treatment of ADHD, (2) diagnostic approaches based on the evaluation of symptom severity (a categorical approach) compared to underlying behaviors (a dimensional approach), and (3) study designs that are longitudinal or cross-sectional. Introduction