The purpose of this research was to analyse the effect of adding Pregabalin (PGB) on severe symptoms of anxiety and depression in patients with Generalized Anxiety Disorder refractory to duloxetin in daily medical practice in Spain.

This is a post-hoc analysis of a 6-month multicentre, prospective and observational study carried out in outpatient psychiatric clinics in Spain. Men and women, above 18 years, with a diagnosis of GAD according with DSM-IV-TR criteria, pregabalin naïve and refractory to a previous course of duloxetin (3 months or more) and severe symptoms of anxiety (HAM-A ≥24) and depression (MADRS ≥35) were considered eligible for analysis.

A total of twenty-five patients [76% women, mean age; 49.3 (11.8) years, 82% with a comorbid depressive disorder] fulfilled criteria for analysis, and were previously exposed to duloxetin [mean dose: 71.7 (26.7)mg/day] for an average of 6.7 (3.7) months. Adding pregabalin [mean dose: 172.8 (75.5)mg/day], during 5.2 (1.8) months, reduced both anxiety and depressive symptoms by a mean of, respectively in HAM-A and MADRS scales, 54.1% (from 36.5±4.3 pts to 16.6±9.1 pts; p<0.001, effect size: 4.63) and 52.8% (from 40.4±4.6 pts to 19.0±11.0 pts; p<0.001, effect size: 4.65). As a result, the percentages of patients without symptoms of either anxiety or depression were 30% and 24%, respectively.

Despite small sample, adding pregabalin had a meaningful and significant effect on severe symptoms of anxiety and depressive symptoms in patients with severe GAD and concomitant depressive disorder resistant to duloxetin.