Background: Mirtazapine, a clinically effective antidepressant, acts by antagonizing central alpha2-adrenergic and 5-HT2/5-HT3 receptors. No data are available regarding mirtazapine's effects on sleep architecture in patients with major depressive disorder.
Methods: Six patients meeting criteria for major depressive disorder and scoring > or =4 on the three Hamilton Depression Rating Scale sleep items were studied. Polysomnographic evaluations were performed at baseline and after 1 (15 mg at bedtime) and 2 weeks (30 mg at bedtime) of open-label mirtazapine treatment.
Results: Mirtazapine significantly decreased sleep latency and significantly increased total sleep time and sleep efficiency from baseline levels during week 1, with similar results observed after week 2. Mirtazapine did not significantly alter rapid eye movement sleep parameters. Clinically, Hamilton Depression Rating Scale and sleep disturbance ratings improved after treatment.
Conclusions: Mirtazapine significantly improves sleep continuity in major depressive disorder patients with poor sleep quality at weeks 1 and 2 of treatment, while preserving sleep architecture.