A Randomized, Placebo-Controlled Pilot Study of Quetiapine-XR Monotherapy or Adjunctive Therapy to Antidepressant in Acute Major Depressive Disorder with Current Generalized Anxiety Disorder

Abstract To pilot efficacy and safety data of quetiapine-XR monotherapy or adjunctive therapy to antidepressant(s) in the acute treatment of MDD with current generalized anxiety disorder (GAD). The Mini International Neuropsychiatric Interview was used to ascertain the diagnosis of DSM-IV Axis I disorders. Eligible patients were randomly assigned to quetiapine-XR or placebo for up to 8 weeks. Changes from baseline to endpoint in Hamilton Depression Rating Scale-17 items (HAMD-17), Hamilton Anxiety Rating Scale (HAM-A), Clinical Global Impression-Severity (CGI-S), Quick Inventory of Depression Symptomatology-16 items Self-Report (QIDS-16-SR) total scores, and other outcome measures were analyzed with the last observation carried forward strategy and/or mixed-effects modeling for repeated measures. Of the 34 patients screened, 23 patients were randomized to receive quetiapine-XR (n = 11) or placebo (n = 12), with 5 and 4 completing the study, respectively. The mean dose of quetiapine-XR was 154 ± 91 mg/d. The change from baseline to endpoint in the total scores of HAMD-17, HAM-A, QIDS-16-SR, and CGI-S were significant in the quetiapine-XR group, but only the change in HAM-A total score was significant in the placebo group. The differences in these changes between the two groups were only significant in CGI-S scores, with the rest of numerical larger in the quetiapine-XR group. The most common side effects from quetiapine-XR were dry mouth, somnolence/sedation, and fatigue. In this pilot study, quetiapine-XR was numerically superior to placebo in reducing depressive and anxiety symptoms in patients with MDD and current GAD. Large sample studies are warranted to support or refute these preliminary findings.