Generalized anxiety disorder in patients with major depression: is DSM-IV's hierarchy correct?

DSM-III imposed a hierarchical relationship in the diagnosis of anxiety disorders in depressed patients, stipulating that anxiety disorders could not be diagnosed if their occurrence was limited to the course of a mood disorder. In the subsequent versions of the DSM this hierarchy was eliminated for all anxiety disorders except generalized anxiety disorder. The authors examined the validity of this remaining hierarchical relationship between mood and anxiety disorders.

Psychiatric outpatients with major depressive disorder (N=332) were evaluated with a semistructured diagnostic interview and completed paper-and-pencil questionnaires on presentation for treatment. To study the validity of the DSM-IV hierarchical relationship between generalized anxiety disorder and mood disorders, the authors made a diagnosis of modified generalized anxiety disorder for patients with major depressive disorder who met all the criteria for generalized anxiety disorder except for the exclusion criterion. The analyses compared the characteristics of three nonoverlapping groups of patients with DSM-IV major depressive disorder: 1) those with coexisting DSM-IV generalized anxiety disorder, 2) those with coexisting modified generalized anxiety disorder, and 3) those with neither DSM-IV nor modified generalized anxiety disorder.

Compared to the depressed patients without generalized anxiety disorder, the depressed patients with DSM-IV and modified generalized anxiety disorder had higher levels of suicidal ideation; poorer social functioning; a greater frequency of other anxiety disorders, eating disorders, and somatoform disorders; higher scores on most subscales of a multidimensional self-report measure of DSM-IV axis I disorders; a greater level of pathological worry; and a higher morbid risk for generalized anxiety disorder in first-degree family members. The two generalized anxiety disorder groups did not differ from each other.

The findings question the validity of the DSM-IV hierarchical relationship between major depressive disorder and generalized anxiety disorder and suggest that the exclusion criterion should be eliminated.