PREVALENCE AND COMORBIDITY OF DSM-III-R DIAGNOSES IN A BIRTH COHORT OF 15 YEAR OLDS

Objective: To document the prevalence and comorbidities of a range of DSM-III-R diagnoses in a birth cohort of approximately 1,000 New Zealand children. Method: Parent and child reports were obtained on levels of DSM-III-R symptomatology in the child for five major groups of diagnoses: anxiety disorders, mood disorders, conduct/oppositional disorders, attention-deficit hyperactivity disorder, and substance abuse/dependence. Two methods, optimal informant and latent class modeling, were used to combine parent and child reports to produce a ''best estimate'' of the prevalence of disorder. Results: Both methods produced very similar results. Overall approximately 25% of children met criteria for at least one DSM-III-R diagnosis. Rates of disorder were higher for girls (33% approximately) than for boys (20% approximately), this difference being largely owing to higher rates of anxiety and mood disorders among girls. There were strong tendencies for disruptive behavior and substance use disorders to cluster together and more diffuse tendencies for anxiety and mood disorders to be comorbid with each other and with other disorders. Only a minority (21%) of children with disorder were in contact with any service for their problems. Conclusion: These findings are consistent with a number of other studies of adolescent populations, both in terms of the prevalence of disorder and the comorbidities between disorders.