Sex differences in neurodevelopmental disorders

Purpose of review There continues to be more males than females diagnosed with neurodevelopmental disorders, which may provide clues about their cause. This review will focus on the two most common neurodevelopmental disorders - autism spectrum disorder (autism) and attention deficit hyperactivity disorder (ADHD), and explore recent research to understand recent developments in the field. Recent findings Biological mechanisms including genetics, hormones and their interaction with other risk factors, such as stress and lead exposure, point to complex causal pathways for neurodevelopmental disorders. Over recent years, the research focus on sex differences in symptom profiles in autism has continued; however, a meta-analysis of existing studies indicated minimal sex differences in core autism symptoms. In ADHD, changes in the sex ratio from disparity in childhood to parity in adulthood may relate to the onset and trajectory of hyperactivity symptoms in females. Research into medical and psychiatric comorbidities, such as polycystic ovary syndrome and gender dysphoria, is also providing insights into the role of early androgen exposure as a potential causal factor for neurodevelopmental disorders. Summary The factors, which contribute to an increased number of males with neurodevelopmental disorders in most cases are complex involving interactions between genetics, hormones and environmental factors.