Alteration in circadian rhythms in bipolar disorder: Mechanisms and implications

Rate of change in solar insolation is a hidden variable that influences seasonal alterations in bipolar disorder

“…Sleep disturbances also occurred in BD patients when in remission, including longer sleep durations, longer latencies to fall asleep, and more frequent awakenings after sleep onset compared to healthy controls. In addition, BD patients in remission displayed greater variability in daily patterns of sleep and wakefulness compared to controls, with a preference for an evening chronotype, a more variable bedtime, shorter duration of sleep, and reduced self‐reported sleep satisfaction (Dallaspezia & Benedetti, 2021 ; Hensch et al., 2019 ).…”

Association between polarity of first episode and solar insolation in bipolar I disorder

“…Disruptions in circadian rhythms can be defined as misalignment in biological timing between different levels of the circadian clock system, or as misalignment with the environmental light/dark cycle [63,64]. Many symptoms of circadian rhythm disruption are documented in BD, including irregular sleep-wake cycles, abnormal melatonin secretion, evening chronotype, supersensitivity to phase delaying effects of light, metabolic dysregulation, and irregular social rhythms [11,12,15,65,66]. Circadian rhythm disruption may result in mitochondrial dysfunction and contribute to the pathogenesis of BD [67,68].…”

“…Alterations in circadian rhythms across the lifespan are associated with psychiatric disorders including mood disorders, schizophrenia, anxiety disorders [4][5][6][7][8], and neurodegenerative diseases [9,10]. Patients with bipolar disorder (BD) exhibit symptoms of circadian disruption, such as sleep disturbances, social rhythm alterations and endocrine abnormalities, and these symptoms may persist during remission [11][12][13][14][15]. The consequences of circadian dysfunction in BD may both trigger and exacerbate episodes [16,17].…”