Phase relationships between core body temperature, melatonin, and sleep are associated with depression severity: Further evidence for circadian misalignment in non-seasonal depression

Abstract

Misalignment between the timing of sleep and the circadian pacemaker has been linked to depression symptoms. This study sought to extend earlier findings by comparing sleep and circadian markers in healthy controls and individuals with major depression. Two markers of circadian misalignment correlated with depression severity in the depressed group.

Sleep and Emotional Functions

“…Even a minimal misalignment between circadian phase and sleep phase can deteriorate mood (Danilenko et al 2003), which may also in part explain mood-related problems (e.g., irritability) in jet-lag (Waterhouse et al 2005), and severity of unipolar depression (Hasler et al 2010). Stress can also disrupt the circadian cycle (Meerlo et al 2002), leading to depressive episodes in vulnerable individuals (Ehlers et al 1988).…”

Ambulatory sleep-wake patterns and variability in young people with emerging mental disorders

“…[15][16][17] Similarly, in both community-based and clin ical samples, depression has been associated with prolonged sleep onset latency, poorer sleep consolidation, extended or delayed sleep duration and phase shifts of the sleep-wake cycle. 14,[18][19][20][21][22][23][24] Compared with age-matched controls, young people with bipolar disorder have longer sleep onset latency and increased nighttime awakenings, and they report worse sleep quality and spending extended time asleep. 25,26 The literature on psych otic disorders is scarcer, but compared with healthy controls, patients with schizophrenia have been found to have longer sleep onset latency, extended sleep duration and time in bed, delayed sleep-wake profiles and higher intraindividual variability.…”

A PERIOD3 variant causes a circadian phenotype and is associated with a seasonal mood trait

“…An example of this is seasonal affective disorder, also known as "winter depression," which is among the most common mood disorders, with a reported prevalence of 1.5-9%, depending on latitude (2). In addition, shift work has been suggested as a risk factor for major depressive disorder (3), and depression severity correlates with the degree of circadian misalignment (4,5). A number of genetic variants in core clock genes have been reported as statistically associated with mood disorders, including seasonal affective disorder and major depressive disorder (6)(7)(8)(9)(10)(11)(12)(13)(14), but to date none has been causally related with an understanding of specific molecular links.…”