Comorbidity of anxiety and depression in children and adolescents: an integrative review.

Much evidence exists documenting the comorbidity of anxiety and affective disorders in youth. Furthermore, comorbidity appears to have serious implications both in terms of severity of impairment and course of disorder. Despite this, little is known about the meaning behind the high rate of co-occurrence of anxiety and depression in children and adolescents. Several conditions exist that may give rise to comorbidity. Specifically, two disorders may be comorbid when there is a high rate of symptom overlap between the disorders, when one underlying construct is split into two separate disorders, when the disorders share common risk or etiological factors, or because one disorder causes or increases the risk of developing the second disorder. The present paper examines each of these explanations as they relate to the comorbidity of anxiety and depression in youth.