Retrospectively reported median (and inter-quartile range) AOO of any disorder is 8 (6-13) years old. A clear temporal order exists across disorders within classes. (Figure 1) Specific phobia has the earliest AOO (Median) within fear disorders (6), separation anxiety disorder within distress disorders (8), and attention-deficit/hyperactivity disorder within behavior disorders (6). The next earliest AOO distributions are for other fear (11-12) and behavior (12-13) disorders. Bipolar disorder (14), the remaining distress disorders (14), eating disorders (15), and substance disorders (16) have the latest median AOO.
