Emotional blunting with bupropion and serotonin reuptake inhibitors in three randomized controlled trials for acute major depressive disorder

Abstract

BackgroundEmotional blunting is theorized to be an adverse effect of antidepressants, particularly serotonin reuptake inhibitors, but this has not been firmly established. Another possibility is that emotional blunting represents a residual depressive symptom. MethodsWe analyzed data from adult outpatients with acute major depressive disorder who participated in three 8-week randomized controlled trials. Trials 1 and 2 were pooled (venlafaxine, n = 378; bupropion, n = 389; placebo, n = 383) and Trial 3 (escitalopram, n = 254; bupropion, n = 260) was analyzed separately. Emotional blunting was measured with the “inability to feel” item from the Montgomery-Åsberg Depression Rating Scale. ResultsEmotional responsiveness improved, on average, in all treatment groups. Only a minority of participants (≤6 %) experienced more emotional blunting post-treatment, compared to baseline, with no significant differences between treatment groups, although roughly 20–25 % continued to report an inability to feel normal emotions at the final assessment. In Trials 1 and 2, emotional blunting was associated with poorer outcomes in terms of depressive symptoms, suicidal ideation, and sexual function, but these correlations were nearly identical in the placebo group. LimitationsThe trials were short and cannot speak to the possibility of emotional blunting from long-term treatment. Emotional blunting was measured with a single item. ConclusionsThe study medications did not significantly decrease emotional responsiveness, and there was no evidence that emotional blunting mediated treatment response. In acute treatment, emotional blunting may be better conceptualized as a residual symptom than as an adverse drug effect.