Adjunctive Pregabalin in Partial Responders With Major Depressive Disorder and Residual Anxiety

Background: Anxiety symptoms in depression result often in treatment resistance, residual symptoms, and persistent functional impairment. Objective: To assess the effectiveness and safety of adjunctive pregabalin to antidepressants for residual anxiety in patients with major depressive disorder (MDD). Methods: A retrospective chart review was conducted to identify partial responders among patients with MDD with residual anxiety. Twenty such patients (age, 58.4 +/- 11.2 years; 15 women; baseline Hamilton Depression Rating Scale [HDRS], 17.1 +/- 3.5) who received adjunctive pregabalin for residual anxiety were included. Antidepressants augmented were the selective serotonin reuptake inhibitors (n = 12), mirtazapine (n = 2), and selective serotonin-norepinephrine reuptake inhibitors (n = 6). Results: Twenty patients received at least 4 weeks of pregabalin treatment after 8 weeks of antidepressant therapy. At week 1 (9 weeks after initiating treatment), pregabalin was prescribed at a mean +/- SD dose of 71.2 +/- 31.7 mg, and the mean maximum pregabalin dose prescribed was 156.2 +/- 76.5 mg (range, 75-300 mg). At week 8, there were 13 responders (13/20 [65%]), and 7 of these 13 patients achieved remission (HDRS17 < 8). There were significant decreases in HDRS scores (13.5 +/- 3.1 vs 9.1 +/- 2.9, P < 0.000), and HDRS anxiety/somatization subscale scores (6.3 +/- 2 to 3.6 +/- 1.7, P < 0.000). Adverse effects included somnolence (n = 7), weight gain (n = 3), dizziness (n = 4), dry mouth (n = 6), edema (n = 3), blurred vision (n = 3), difficulty with concentration/attention (n = 8), headache (n = 6), and diarrhea (n = 5). Conclusions: The results suggest a possible augmentation role for pregabalin when used in conjunction with conventional antidepressants for residual anxiety in MDD.