Quetiapine as an adjunctive pharmacotherapy for the treatment of non-remitting generalized anxiety disorder: A flexible-dose, open-label pilot trial

BackgroundGeneralized anxiety disorder (GAD) is a chronic disorder associated with significant morbidity and disability. Traditional therapies are associated with poor levels of remission, and often result in troublesome side effects.MethodsThis was a 12-week, open-label, flexible-dose study to assess the efficacy and tolerability of quetiapine as an adjunctive treatment to traditional medication. 40 outpatients with GAD who had not achieved remission following at least 8 weeks of an adequate dose of traditional therapy were enrolled. The primary endpoint was the mean change from pre-treatment to week 12 in the Hamilton Anxiety Rating Scale (HAM-A) total scores. Secondary endpoints included: the proportion of patients achieving remission (HAM-A total score of ≤10 at week 12), Clinical Global Impressions-Severity of Illness (CGI-S), Clinical Global Impressions-Global Improvement (CGI-I), Pittsburgh Sleep Quality Index (PSQI) and Penn State Worry Questionnaire (PSWQ).ResultsAdjunctive quetiapine (mean dose 386 mg/day at week 12) significantly reduced the HAM-A total scores from pre-treatment (29.8 ± 9.0) to week 12 (9.0 ± 10.2) (−20.6; p < 0.001). The HAM-A remission rate was 72.1% at week 12. Adjunctive quetiapine resulted in a significant reduction in all efficacy measures by study end. Quetiapine was well tolerated: the most common adverse event (AE) was sedation, with no incidence of serious AEs and no clinically significant changes in vital signs, weight (mean gain 0.5 kg at week 12) or laboratory assessments.ConclusionThe results of this small pilot trial suggest that quetiapine adjunctive to traditional therapy may be a useful treatment in patients with GAD or treatment-resistant GAD, and warrant further investigation.