ABSTRACT
One of the main advantages of epidemiological research using samples from the general population is the ability to produce findings of greater generalizability than studies of clinical samples. Data from clinical settings are generally unrepresentative of individuals with conduct disorder (CD) and oppositional defiant disorder (ODD) or other psychiatric disorders because of bias in service attendance through restrictions in evaluating, access, and selection processes in terms of help-seeking behavior, symptoms, and chronicity (Essau, Petermann, & Feehan, 1997). Samples from the community and clinical settings may also differ in the risk factors, comorbidity, natural history, and response to treatment of their CD and ODD. An additional problem with using clinical samples is that children’s referrals to clinical settings may be related to parental characteristics such as tolerance level, stress, and the presence of psychopathology (Shepherd, Oppenheim, & Mitchell, 1971). The finding that most children in the community with significant problems do not receive adequate help (Essau, 2002; McGee, Feehan, & Williams, 1995) also underscores the importance of epidemiological studies. For these reasons, numerous epidemiological studies on CD and ODD have been conducted in recent years. This chapter reviews these studies with an emphasis on the prevalence and comorbidity of CD and ODD in children and adolescents. Data from clinical studies is also reviewed, as they could contribute to our understanding of the etiological mechanisms in CD/ODD.
