In the context of these limitations, the differential AOO patterns found here are consistent with considerable previous evidence that attention-deficit/hyperactivity disorder, specific phobia, and separation anxiety disorder have the earliest ages-of-onset and that generalized anxiety, depressive, and substance disorders have the latest ages-of-onset of the adolescent disorders considered here (Kessler et al., 2007). Very similar patterns were found in parallel analyses we previously carried out in a cross-national sample of adults (Kessler et al., 2011). The high comorbidity found among disorders is also consistent with previous evidence (Angold et al., 1999).
