Aims:
To study the impact of comorbid personality disorders (PDs) on outcome in 1) a medication trial for major depression (MD) and 2) a psychotherapy trial for MD.
Method:
Two treatment trials for patients with MD were performed: 1) randomized clinical trial of fluox-etine vs. nortriptyline with open follow-up (n = 195) and 2) randomized clinical trial of interpersonal psychotherapy (IPT) vs. cognitive behavioural therapy (n = 177).
Results:
Comorbid PD had no impact on the outcome of MD in patients treated with medication over the short term. Avoidant PD was associated with poorer outcome over the longer term. Comorbid PD had a negative impact on the outcome of MD in patients treated with psychotherapy over the short term. This was largely explained by the poor response to IPT in depressed patients with comorbid PD.
Discussion:
The finding that comorbid PD adversely affects the outcome in depressed patients treated with psychotherapy but not with drugs is consistent with other studies. Possible mechanisms are discussed.