Comorbidity of Externalizing and Internalizing Problems

Abstract

Comorbidity refers to the coexistence of two or more distinct disorders or syndromes in the same individual. Research findings are presented showing comorbidity of externalizing (aggression and delinquency), internalizing (anxiety, depression, somatic complaints, and withdrawal), and attention problems. Comorbidity is discussed within the conceptual framework of the categorical classification system of DSM diagnoses and a quantitative taxonomy based on the Child Behavior Checklist (CBCL) and Teacher's Report Form (TRF). High comorbidity rates are reported for DSM diagnoses of conduct disorders with oppositional disorders, affective disorders, anxiety disorders, and attention deficit disorders. High comorbidity also was found for paired combinations of the CBCL and TRF Aggressive Behavior, Delinquent Behavior, Anxious/Depressed, and Attention Problems syndromes. Implications of comorbidity are discussed for determining special education eligibility and designing school-based interventions.