Antidepressants and Sleep: Neurophysiology and Clinical Correlates

Introduction: Depression is a common disorder associated with significant disability and is a substantial burden on the individual, their relatives and friends, and on society as a whole. Sleep disturbances are key features of depressive symptomatology, with more than 80% of depressed patients complaining of poor quality sleep. Methods: The range of available antidepressants is here reviewed in relation to mechanisms of action and the evidence of sleep alteration in patients with depression. Results: The available treatments are largely effective but their use is compromised by poor tolerability and low adherence to treatment. It is also clear that currently used antidepressant agents tend to disrupt sleep architecture. Agomelatine, a novel antidepressant, has been found successful in treating depressed patients. Because of its dual mechanism of action on MT1 and MT2 melatonin receptors in the SCN and its 5-HT2c antagonist properties, agomelatine has been effective in improving both quality of sleep and mood in depressed patients. Conclusions: There is clinical and epidemiological evidence that sleep disturbances in depression constitute a risk factor for poor clinical outcomes. Specifically, insomnia complaints precede the onset and recurrence of depression. For this rea- son antidepressants with a faster onset of action, with less interferences on sleep architecture would be expected to bring larger numbers of depressed patients to full remission.