Abstract: The primary aim of the present study was to compare the effects of agomelatine (AGO) and venlafaxine XR (VLX) on anhedonia in patients with major depressive disorder. Secondary end points were to test its antidepressant and anxiolytic efficacy.
Sixty patients were enrolled and randomly assigned to two different treatments: AGO (25-50 mg/d; n = 30 subjects) or VLX (75-150 mg/d, n = 30 subjects). Psychopathological assessment was performed at baseline and after 8 weeks of treatment with the Snaith Hamilton Rating Scale (SHAPS), the Hamilton Depression Rating Scale, the Hamilton Anxiety Rating Scale, and the Clinical Global Impression for anhedonia, depression, anxiety, and global improvement, respectively.
Both groups showed a significant reduction in time for the SHAPS, the Hamilton Depression Rating Scale, and the Hamilton Anxiety Rating Scale. A significant between-group difference was observed for SHAPS scores: patients treated with AGO showed a more relevant reduction compared with that in VLX-treated patients. Moreover, only patients treated with AGO showed a statistically significant improvement in Clinical Global Impression scores.
In this study, AGO showed significantly greater efficacy on anhedonia and similar antidepressant efficacy to the serotonin-norepinephrine reuptake inhibitor VLX in patients with major depressive disorder during an 8-week treatment period. Anhedonia has been considered a potential trait marker related to vulnerability for depression. Therefore, the efficacy of AGO on this dimension holds particular importance in the treatment of patients with anhedonic features.