To analyse the effect of Pregabalin (PGB) on anxiety and depression symptoms in patients with refractory-severe Generalized Anxiety Disorder (GAD) and severe concomitant depressive disorder.

Post-hoc analysis of a multicentre, prospective and observational study conducted in outpatient psychiatric clinics to ascertain the impact of broadening GAD criteria. Men and women above 18 years, with GAD (DSM-IV criteria), PGB naïve and refractory to a previous course of benzodiazepines and/or anti-depressive drugs (minimum 3 months) and severe symptoms of anxiety (HAM-A ≥ 24) and depression (MADRS ≥ 35) were included. Changes in HAM-A and MADRS were assessed after 6 months of receiving PGB as per psychiatrist's judgement.

159 patients [69.2% women, 45.9 (12.6) years] fulfilled criteria for analysis. Respectively, 92% and 90% of subjects were previously exposed to benzodiazepines and anti-depressives before adding PGB [mean dose: 223.1 (126.3) mg/day]. PGB therapy reduced both anxiety and depressive baseline symptoms by a mean of, respectively in HAM-A and MADRS scales, 57.9% (from 35.5±5.8 to 14.8±9.4; p< 0.001, effect size: 3.57) and 58.1% (from 39.4±4.3 to 16.5±10.3; p< 0.001, effect size: 5.33). As a result, the percentages of patients without symptoms of both anxiety and depression were 34.4% and 40.9%, respectively at the 6 month visit (p< 0.001 in all cases). Similarly, responder rates (≥ 50% reduction of baseline scoring) were 63.1% and 62.9%.

Despite limitations, Pregabalin therapy had a meaningful and significant effect of symptoms of anxiety and depression in patients with severe refractory GAD and concomitant severe depressive disorder.