Psychiatric Comorbidity as a Predictor of Clinical Response to Nortriptyline in Treatment-Resistant Major Depressive Disorder

Background: A number of studies of major depressive disorder suggest that psychiatric comorbidity may contribute to treatment resistance. The purpose of this study was to test whether the presence of comorbid Axis I and Axis II disorders predicts clinical response to an open trial of nortriptyline among patients with treatment-resistant depression.

Method: Ninety-two outpatients with treatment-resistant DSM-III-R major depressive disorder were enrolled in a 6-week open trial of nortriptyline (Nov. 1992-Jan. 1999). The presence of comorbid Axis I and Axis II disorders was established at baseline with the use of the Structured Clinical Interview for DSM-III-R. Chi-square analyses were used to test Axis I or Axis II comorbid conditions as a predictor of clinical response to nortriptyline.

Results: Thirty-nine patients (42.4%) responded to nortriptyline. The presence of avoidant personality disorder (p < .01) predicted poorer response to nortriptyline. The response rate was 16.7% for patients with and 48.6% for patients without comorbid avoidant personality disorder. No other comorbid diagnoses were found to predict clinical response in a statistically significant manner.

Conclusion: The presence of avoidant personality disorder conferred a poorer prognosis in treatment-resistant depression patients treated with nortriptyline.