Preliminary experience with adjunctive quetiapine in patients receiving selective serotonin reuptake inhibitors

Treatment of depression and anxiety disorders with selective serotonin reuptake inhibitors (SSRIs) has been shown by numerous studies to be generally effective. Less well understood is how clinically to address the residual anxiety symptoms a significant minority of such patients treated with SSRIs continue to experience. We assessed quetiapine as adjunctive therapy to SSRIs for patients with anxiety symptoms complicating a depressive or anxiety disorder. Patients receiving a stable dosage of an SSRI for at least 6 weeks who also had persistent anxiety symptoms (Hamilton Anxiety scale [HAM-A] ≥ 16), were enrolled in a 9-week, open-label, variable dose study. Changes in clinical status were assessed with the Hamilton Depression Rating Scale (HAM-D), HAM-A, and State Anxiety Inventory (SAI). Statistically and clinically significant reductions of ≥ 50% in the HAM-D and HAM-A occurred by the second week of treatment in 10 of the 11 patients. These improvements continued throughout the study along with a significant improvement on the SAI scale. The most frequent side effects reported were mild dry mouth, constipation, and transient drowsiness with dose escalation. The results provide evidence that quetiapine may be an effective adjunctive treatment for recalcitrant anxiety symptoms in individuals treated with SSRIs for either anxiety or depressive disorders. Given the open-label design of the trial, more rigorous studies are clearly indicated.