As a number of prospective studies of child-adolescent mental disorders exist (Costello et al., 2003; Newman et al., 1996; Pine et al., 1998; Reinke & Ostrander, 2008), a question can be raised why retrospective analysis of the sort reported here has value. The answer is that most existing prospective studies, with a small number of notable exceptions (Wittchen et al., 1998; Olino et al., 2010), did not obtain data on lifetime prevalence of mental disorders, making it impossible to carry out analyses of the associations between prior lifetime disorders and subsequent first lifetime onset of secondary disorders in the majority of such studies. Replication of the kinds of analyses reported here should be encouraged in the prospective studies that would support them. The results of the current analyses should be useful in providing preliminary hypotheses to be investigated in these prospective studies. This has traditionally been a major value of retrospective studies (Mantel & Haenszel, 1988).
