Circadian Rhythm Disturbances in Mood Disorders: Insights into the Role of the Suprachiasmatic Nucleus

Table 1

Sleep and circadian disturbances in major depressive disorder and bipolar disorder.

Psychiatric disorder	Sleep and circadian disturbances
Major depressive disorder	Reduced latency to REM, increased REM time, and decreased slow-wave sleep [45–48]; Advanced hormonal rhythms [48–50]; Delayed rhythms or an evening chronotype [51–55]; Reduced body temperature amplitude and increased body temperature at night [50, 61, 62]; Dampened activity, cortisol, thyroid-stimulating hormone, melatonin, and heart rate rhythms [50, 63–65]
Bipolar disorder	Reduced sleep during mania and hypersomnia or insomnia during depression (as reviewed in [70]); Reduced latency to REM and increased REM density during mania [71–73]; Evening chronotype [81–83]; Less rhythmic and dampened rhythms [77–80]; Phase delayed or phase-advanced sleep-wake, metabolite, hormone, or body temperature rhythms [84–87]; Advanced rhythms during mania and/or delayed rhythms during depression [88–90]; Increased sensitivity to light-induced melatonin suppression [91, 92]