To determine the incidence and clinical correlates of functional and quality of life (QoL) impairment in patients with generalized anxiety disorder (GAD), and to evaluate the efficacy of pregabalin and venlafaxine-XR in improving functional outcomes.

A double-blind trial in adults who met DSM-IV criteria for GAD, with a HAM-A total score ≥20, randomized to 8-weeks of flexible-dose treatment with pregabalin (300-600 mg/d, N=121), venlafaxine-XR(75-225 mg/d, N=125), or placebo (N=128). Anxiety-related impairment in QoL was evaluated using the Quality of Life, Enjoyment, and Satisfaction Questionnaire (Q-LES-Q) and impairment in functioning using the Sheehan Disability Scale (SDS).

At baseline, a similar proportion of patients in the 3 treatment groups met criteria for impairment on the Q-LES-Q (70.1%-77.6%) and SDS (74.1%-82.7%). For all groups combined, baseline impairment was more highly correlated with psychic than somatic anxiety on both the Q-LES-Q and SDS (Spearman r-values, -0.32 vs. -0.28 and 0.27 vs. 0.14,respectively). On the SDS but not on the Q-LES-Q, significantly more subjects in the pregabalin (67.2%) and venlafaxine-XR (59.5%) groups had improvement into the normative range compared with placebo (42.9%; p< 0.05) at endpoint. The mean HAM-A change score (all subjects) was significantly greater among patients whose Q-LES-Q returned to normal (“remitters” vs. non-remitters: -19.3 vs. -11.9; p< 0.05).

At baseline, approximately 75% of GAD patients reported moderate-to-severe impairment in QoL and functioning which was modestly correlated with severity of GAD symptomatology. Pregabalin produced improvement in QoL and functioning that was correlated with reduction in anxiety symptom severity.