Effects of Mood Stabilizers on Sleep and Circadian Rhythms: A Systematic Review

Mood disorders tend to be recurrent, chronic, and disabling, caused by a complex interplay of factors. Within this context, sleep, which is crucial for mental health, may contribute to mental disorders, including mood disorders. Sleep disturbances can serve as risk factors for the onset, exacerbation, and relapse of mood disorders. Treatments for mood disorders should ideally normalize sleep disturbances or may act on mood symptoms through sleep regulation. In this context, the present work aims to systematically review the effects on sleep of mood stabilizers such as lithium as well as carbamazepine, lamotrigine, olanzapine, quetiapine, and valproate. A systematic review was implemented to draw useful insights from the literature on the drugs chosen. A total of 85 studies were retained after meeting the inclusion/exclusion criteria. The largest amount of evidence is for lithium as a potential regulator of sleep and circadian rhythm systems. Although fewer studies have been conducted on valproate, it is also emerging as a potential regulator of the sleep and circadian systems. Conversely, more studies are needed for other mood stabilizers such as lamotrigine, carbamazepine, quetiapine, and olanzapine. First-generation mood stabilizers like lithium and valproate may exert a regulating role on sleep and circadian systems, demonstrating a tendency to normalize sleep disturbances associated with mood disorders. It is possible that their impact on mood regulation occurs through the regulation of the sleep and circadian systems.