MAOI efficacy and safety in advanced stage treatment-resistant depression--a retrospective study

Evidence-based data suggest that MAOI therapy may be effective in up to 50% of patients with treatment-resistant depression (TRD). We hypothesized that MAOI therapy is similarly effective in patients with advanced stage TRD who are unresponsive to > or = 4 prior antidepressant drug (AD) trials compared to patients with early stage TRD who are unresponsive to < or = 3 prior AD trials.

To test this hypothesis, data were harvested from 400 patient charts. Of these, 59 patients received a total of 75 MAOI treatment trials. 50 patients had 1 MAOI trial and 9 patients had 2 or more MAOI trials. Response was assessed using the Clinical Global Impressions Change (CGI/C) scale.

56% of MAOI trials resulted in a CGI/C score of 1 ("very much better") or 2 ("much better"). Only 25% resulted in a CGI/C score of 4 or more ("no change" or "worse"). 32.5% of MAOI trials resulted in a CGI/C score of 1 in patients with early stage TRD, while only 12.1% of MAOI trials resulted in a CGI/C score of 1 in patients with advanced stage TRD (p=0.04). There was a significant negative correlation between the number of prior, failed AD trials and the final CGI/C score (p=0.03). The odds associated with attaining a CGI/C score of 1 diminished by a factor of 30% with each prior failed AD trial. We observed only 1 case of acute hypertension which responded to sublingual nifedipine therapy.

The sample size was limited, and MAOI outcome was not compared with other AD therapy. The adequacy of prior AD trials could not always be verified.

These data suggest that MAOI therapy may be beneficial in patients with early stage TRD who are unresponsive to < or = 3 prior treatments. However, the relative efficacy of MAOI therapy in advanced stage TRD remains uncertain.