Does theta burst stimulation have differential benefit for those with melancholic or non-melancholic depression?

To determine if theta burst stimulation (TBS) is of preferential benefit to those with melancholic or non-melancholic depression as an adjunctive treatment for treatment resistant depression (TRD).

Fifty-two patients receiving TBS at a private psychiatric hospital participated in a naturalistic study. Four diagnostic strategies were used to assign melancholic versus non-melancholic depression subtype status. Depression symptoms were assessed at baseline, mid-treatment, and end of treatment using the Montgomery-Ǻsberg Depression Rating Scale - Self-Assessment (MADRS-S). Forty-one participants also completed the MADR-S at a six-week follow-up assessment.

We quantified poor correlations between the four study measures of melancholia; a finding suggesting that valid measurement of melancholia is likely to remain problematic. TBS led to significant reductions in depression symptoms from baseline to end of treatment, with this effect maintained at follow up. Response rates for the whole sample were 61.5 % at end of treatment and 53.7 % at follow-up, while remission rates were 34.6 % at end of treatment and 31.7 % at follow-up. Improvement rates as well as responder and remission rates were comparable for the melancholic and non-melancholic groups, irrespective of the diagnostic strategy used.

The study was naturalistic (i.e., there being no control group, and concomitant medication changes were allowed), depression severity was assessed only by use of self-report measures, and the sample size was relatively small.

TBS appears to be non-specific, in that we failed to quantify any statistically significant differential benefit for those with melancholic compared to those with non-melancholic depression.