Effects of adjunctive antidepressant therapy with quetiapine on clinical outcome, quality of sleep and daytime motor activity in patients with treatment‐resistant depression

Abstract

To investigate the effects of antidepressant therapy plus quetiapine on major depression, motor activity, daytime sleepiness and quality of sleep. Patients (N = 27) with major depressive disorder received a standard antidepressant treatment (Venlafaxine, Escitalopram) plus flexible dose of quetiapine. Patients' depression was monitored with HAM-D-21, motor activity was continuously measured with actigraphy and sleep parameters with the Pittsburgh Sleep Quality Index (PSQI) over 4 weeks. Whereas depression, quality of sleep and daytime sleepiness showed a significant improvement over 4 weeks, change of daytime motor activity was significant only between the wash out period and the last 2 days of the study. Repeated measures of variance indicate an independent influence of quetiapine on improved depression, motor activity and sleep. While we found only a mild decrease of daytime sleepiness during the first week of treatment, the further decline of daytime sleepiness got significant after 2 weeks of treatment with quetiapine, even at high mean daily doses and despite the sedative effects of quetiapine. Antidepressant treatment plus quetiapine is possibly a suitable treatment strategy to improve clinical depression, quality of sleep and motor activity. Future research is needed to understand the pharmacological interactions between antidepressants and quetiapine in major depression.