Pregabalin augmentation of antidepressants in older patients with comorbid depression and generalized anxiety disorder-an open-label study

Objective The objective of this 12-week open-label study was to evaluate the efficacy, safety, and tolerability of pregabalin as an adjunctive treatment to antidepressants in older patients suffering from depression and comorbid generalized anxiety disorder (GAD). Methods The initial sample of this open-label study consisted of 94 older patients fulfilling criteria for depression with comorbid GAD who were treated with antidepressants. Twenty of them who had received antidepressant monotherapy for an adequate time and shown partial response to the antidepressant prescribed, in terms of either anxiety or depressive symptomatology, followed the next phase. During the 12-week study period, pregabalin was gradually added to the previously prescribed antidepressant, reaching 225 mg/day over 4 weeks. Depression and anxiety scores as well as side effects were monitored. Within groups, differences of depression and anxiety scores at baseline and during the following 12 weeks of treatment were estimated with repeated-measure analysis of variance. Results A statistical significant reduction in depression scores was observed after the 4th week of treatment (p < 0.01), which further improved between the 8th and 12th weeks (p < 0.01). Concerning overall anxiety scores, a statistically significant improvement was noted between the 2nd and 4th weeks (p < 0.01), which further continued throughout the 8th (p < 0.05) and 12th weeks (p < 0.05). Conclusions The present study demonstrated a good therapeutic response to pregabalin in patients with depression comorbid with GAD after a 12-week treatment period. Both anxiety and depressive symptomatology significantly improved, and minimal side effects were observed.