The proportion of individuals with age at the onset before 14, 18 and 25 years of age for specific mental disorders are reported in Table 1. Overall, the proportion of patients developing disorders before age 25 is more than nine out of ten for ASD and ADHD; nine out of ten for social anxiety disorder; around eight out of ten for specific phobia/separation anxiety disorders and anorexia nervosa; seven to eight out of ten for binge eating disorders; six to seven out of ten for OCD and disorders due to use of cannabis; four to five out of ten for disorders due to use of alcohol, schizophrenia, PTSD, panic disorder, and personality disorders; three to four out of ten for GAD, bipolar/related disorders, and depressive disorders; and two out of ten for ATPD. The curves representing the peak age at onset for specific mental disorders are presented in e-Figs. 2–17.
