Psychiatric comorbidity among referred juveniles with major depression: fact or artifact?

The high levels of psychiatric comorbidity reported in juveniles meeting operational definitions of depressive disorders raise both substantive and methodological concerns about whether depression with comorbid disorders should be classified as two disorders or as different manifestations of the same condition. Our purpose was to clarify issues of diagnostic heterogeneity and diagnostic overlap in juvenile depression.

The sample consisted of consecutively referred children and adolescents (N = 424) comprehensively evaluated with structured diagnostic interviews and psychosocial assessments.

A clinical picture compatible with the diagnosis of major depression was identified in 40% of these referred youths. Children meeting criteria for major depression had prototypical symptoms of the disorder, a chronic course, and severe psychosocial dysfunction. In addition, they frequently met criteria for attention-deficit hyperactivity disorder, conduct disorder, and anxiety disorders. These comorbidity findings were not due to symptom overlap among major depression and the co-occurring disorders. For the most part, comorbid disorders preceded the onset of major depression by several years.

Juvenile depression has a chronic course, severe dysfunction, and high levels of psychiatric comorbidity. Despite symptom overlap, our work suggests that major depression and other conditions may represent different disorders.