Adolescents were administered the fully-structured Composite International Diagnostic Interview (CIDI) modified to simplify language and use examples relevant to adolescents (Merikangas et al., 2009 (link)). The 15 DSM-IV disorders assessed include mood disorders (major depressive disorder/dysthymia, bipolar I-II disorder and sub-threshold bipolar disorder), anxiety disorders (panic disorder with or without agoraphobia, agoraphobia without panic disorder, social phobia, specific phobia, generalized anxiety disorder, post-traumatic stress disorder, separation anxiety disorder), behavior disorders (attention-deficit/hyperactivity disorder, oppositional-defiant disorder, conduct disorder, eating disorders [anorexia nervosa, bulimia nervosa, binge-eating behavior]), and substance disorders (alcohol and drug abuse, alcohol and drug dependence with abuse). There were no other exclusionary diagnoses. These disorders include all those assessed in most previous adolescent epidemiological studies.
Adolescent interviews assessed all disorders. Parent questionnaires assessed only disorders for which parent reports have previously been found important in diagnosis: behavior disorders (Johnston & Murray, 2003 (link)) and depression/dysthymia (Braaten et al., 2001 (link)). Parent and adolescent reports were combined at the symptom level using an “or” rule (except in the case of attention-deficit/hyperactivity disorder, where only parent reports were used based on evidence of invalidity of adolescent reports). All diagnoses were made using DSM-IV distress/impairment criteria and organic exclusion rules, but diagnostic hierarchy rules were not used because we wanted to study comorbidity among hierarchy-free disorders.
A clinical reappraisal study interviewed adolescent-parent pairs by telephone with the Schedule for Affective Disorders and Schizophrenia for School-Age Children (K-SADS) Lifetime Version (Kaufman et al., 1997 (link)). As detailed elsewhere, concordance was good between survey and clinical diagnoses (Kessler et al., 2009c (link)), with area under the receiver operating characteristic curve (AUC) of .81-.94 for fear disorders, .79-.86 for distress disorders, .78-.98 for behavior disorders, and .92-.98 for substance disorders. Parent and adolescent reports both contributed to AUC when both were assessed for depression/dysthymia (.75, .71, and .87 for adolescent, parent, and combined reports, respectively), oppositional-defiant disorder (.71, .66, and .85), and conduct disorder (.59, .96, and .98), but only parent reports contributed to AUC for attention-deficit/hyperactivity disorder (.57, .71, and .78). Adolescent disorder AOO reports were obtained retrospectively using probes shown experimentally to maximize recall accuracy among adults (Knauper et al., 1999 ).