Circadian rhythms in depression

Sleep Problems in Elderly Women Caregivers Depend on the Level of Depressive Symptoms: Results of the Caregiver–Study of Osteoporotic Fractures

“…The finding that respondents with the highest prevalence of trouble staying asleep and early morning awakening were in the most stressful caregiving situations and had high depressive symptoms supports this explanation. Moreover, depression is associated with disturbances in circadian rhythms that have effects on early‐morning awakening 44 . It is possible that the use of antidepressant medications treated underlying depression and thus significantly decreased the risk of early‐morning awakening, although a recent report on the SOF cohort found more sleep disruption in respondents who used selective serotonin reuptake inhibitors 45 …”

Reactive rhythms and endogenous clocks

“…However, there is some evidence in favour of such a correlation. Souetre et al (1989) and Tsujimoto et al (1990) have both recently reported negative correlations between Hamilton rating scale scores in depressed subjects and the circadian amplitudes of rhythms in temperature and a variety of hormones.…”

“…While there is an accumulating body of evidence that there is a disturbance of circadian rhythms in the affective disorders (Healy, 1987;Souetre et al 1989;Tsujimoto et al 1990), the disturbances in rhythmicity currently reported do not offer clear support for a body clock hypothesis (Healy & Waterhouse, 1990). An alternative possibility arising from the structure of the circadian system outlined above is that disturbances of rhythmicity may arise from a mismatch between the endogenous period and the environment caused by an inappropriate response to exogenous zeitgebers.…”