Clinical evaluation of the Daily Assessment of Symptoms-Anxiety (DAS-A): a new instrument to assess the onset of symptomatic improvement in generalized anxiety disorder.

Introduction: Rapid onset of symptomatic improvement is a desirable characteristic of new generalized anxiety disorder (GAD) treatments. A validated rating scale is needed to assess GAD symptoms during the first days of treatment.

Aims: To provide clinical data to support the validation of the Daily Assessment of Symptoms-Anxiety (DAS-A), a new instrument to assess onset of symptomatic improvement in GAD.

Methods: We assessed the ability of the DAS-A to detect onset of symptomatic improvement during the first week of therapy in 169 GAD patients randomized to paroxetine 20 mg/day, lorazepam 4.5 mg/day, or placebo for 4 weeks.

Results: On the primary outcome measure, average change from baseline over the first 6 days of DAS-A assessments, lorazepam (-14.5 +/- 1.8 [LS mean, SE]; P= 0.006 vs. placebo) showed a significant improvement versus placebo (-7.85 +/- 1.7), whereas paroxetine (-8.3 +/- 1.7; P= 0.83 vs. placebo) did not. Lorazepam produced a significant treatment effect on the DAS-A at 24 h (P= 0.0004), whereas paroxetine did not (P= 0.5666). Both active drugs produced statistically significant improvement versus placebo on the DAS-A total change score (last-observation carried forward method; LOCF, endpoint). On the DAS-A total change score (observed cases analysis), lorazepam produced statistically significant improvement versus placebo at weeks 1, 2, and 4 (P < 0.05; no week 3 visit), whereas paroxetine, separated from placebo at weeks 2 and 4 (P < 0.05). Both active drugs produced results on the Hamilton Anxiety Rating Scale (HAM-A) at weeks 1 through 4 that were similar to those found on the DAS-A.

Conclusions: These data indicate that the DAS-A can detect symptomatic improvement in GAD patients treated with lorazepam during the first week of treatment, and, in a secondary analysis, as early as 24 h.