The sex ratio for many psychiatric disorders changes across development. In childhood, males have higher rates of neurologic and neurodevelopmental disorders including ASD, ADHD and learning disabilities, with an average 3:1 sex ratio for these conditions. 10 Although males have higher rates of ASD than females, females may actually have greater remission or recovery from early childhood symptoms across development. 11 Rates of behavioral, or externalizing disorders, such as ADHD, ODD and CD, are higher in males in childhood, and the male preponderance continues into adulthood, with a steeper increase in prevalence with increasing age. 12 Similarly, during adolescence males and females initiate substance use at comparable rates, but males increase use faster than females. 13 By contrast, prospective community studies (eg, The Great Smoky Mountains Study 14 ) have shown that the prevalence of mood and anxiety disorders (ie, internalizing disorders) tends to be similar in boys and girls prior to adolescence, but the sex ratio diverges at adolescence with females having higher rates throughout adulthood. 15 Bulimic symptoms also differ between boys and girls across development. Prospective research
