Effects of mirtazapine on sleep polygraphic variables in major depression

Mirtazapine, a noradrenergic and specific serotonergic antidepressant(NaSSA), was administered on a flexible schedule in a sample of 17 drug-free patients meeting DSM-IV criteria for a major depressive episode. Sleep polygraphic recordings were performed before and during acute and chronic treatment. Severity of depression and subjective assessment of changes within different aspects of sleep were also evaluated. During the acute administration (first 2 days), mirtazapine significantly increased total sleep time, sleep efficiency, stage II, stage rapid eye movement and slow-wave sleep percentages, and decreased sleep latency and stage awake percentage. These effects persisted after 5 weeks of treatment. Subjectively, mirtazapine induced an improvement of sleep. This open, noncontrolled study suggests that mirtazapine ameliorates the sleep disturbances encountered in depressed patients both objectively and subjectively.