Switching Versus Augmentation: A Prospective, Naturalistic Comparison in Depressed, Treatment-Resistant Patients

Objective: (1) To directly compare the effectiveness of switching antidepressants with augmenting them in depressed patients who do not respond to an initial adequate trial and (2) to determine whether there is a decreased likelihood of response to a second switch or augmentation trial in those patients who did not respond to the first intervention for treatment-resistant depression.

Method: In a naturalistic, open-label design, all depressed outpatients (DSM-IV criteria) who were treatment resistant were prospectively assessed. Short- and long-term outcomes of switching versus augmentation were compared using the Clinical Global Impressions scale.

Results: In the acute phase, 37 (50.0%) of 74 subjects responded to 1 of the 2 interventions for treatment-resistant depression. Forty-five percent (N = 17) and 56% (N = 20) of the patients who had their antidepressant switched or augmented, respectively, responded to that intervention. Nearly three fourths (71.4%) of the acute responders maintained their response through 6 months of follow-up. In 18 patients who did not respond to the first switch or augmentation, 9 (50.0%) responded to a second trial.

Conclusion: Switching antidepressants was somewhat less effective than augmentation, although this difference was not statistically significant. For patients who do not respond to an augmentation or switch, our results suggest that a second trial for treatment-resistant depression may be as effective as the first.