Major Depressive Disorder and Axis I Diagnostic Comorbidity

Background: Recognition of comorbid conditions in patients presenting for the treatment of depression is clinically important because the presence of other disorders can influence treatment planning. In the present study, we examined the frequency of diagnostic comorbidity in psychiatric outpatients presenting for treatment of nonbipolar major depressive disorder (MDD) and patients’ desire for treatment for the comorbid disorders.

Method: Four hundred seventy-nine psychiatric outpatients with DSM-IV nonbipolar MDD were evaluated with a modified version of the Structured Clinical Interview for DSM-IV.

Results: Excluding nicotine dependence, at the time of the evaluation 64.1% (N=307) of the patients met criteria for at least 1 of the 23 specific Axis I disorders, and more than one third (36.7%, N=176) had 2 or more disorders. Anxiety disorders, as a group, were the most frequent current comorbid disorders (56.8%), and social phobia was the most frequent individual disorder. Including subthreshold conditions, the percentage of patients with at least 1 disorder increased to 73.5%. When the scope of assessment was expanded to include nicotine dependence, nicotine dependence was the most frequent lifetime individual disorder (38.2%) and the second most frequent current disorder (27.3%). There was considerable variability among the disorders regarding desire for treatment of the comorbid condition.

Conclusion: The majority of nonbipolar depressed patients have a current comorbid disorder, especially an anxiety disorder, although the actual rate of comorbidity depends on the breadth of the assessment.