Dim light melatonin onset and circadian temperature during a constant routine in hypersomnic winter depression

Abstract

The onset of melatonin secretion under dim light conditions (DLMO) and the circadian temperature rhythm during a constant routine were assessed in 6 female controls and 6 female patients with winter depression (seasonal affective disorder, SAD) before and after bright light treatment. After sleep was standardized for 6 days, the subjects were sleep-deprived and at bedrest for 27 h while core temperature and evening melatonin levels were determined. The DLMO of the SAD patients was phase-delayed compared with controls (2310 vs 2138); with bright light treatment, the DLMO advanced (2310 to 2135). The minimum of the fitted rectal temperature rhythm was phase-delayed in the SAD group compared with the controls (0542 vs 0316); with bright light treatment, the minimum advanced (0542 vs 0336).

Mood regulation in seasonal affective disorder patients and healthy controls studied in forced desynchrony

“…Since the patients still had a low body temperature amplitude after light therapy, these data are inconsistent with the amplitude hypothesis by Czeisler et al (1987). Contrary to previous constant routine studies (Dahl et al, 1993;Wirz-Justice et al, 1995;Avery et al, 1997), these results suggest that a disturbance of the circadian pacemaker is not likely to be involved in the pathogenesis of SAD. In view of the small number of subjects and the relatively short experimental period, the power of the statistical analysis is limited and the conclusions must be taken with care.…”

“…In both studies, certain characteristics of the circadian rhythm in body temperature (Dahl et al, 1993;Wirz-Justice et al, 1995), melatonin (Dahl et al, 1993) and cortisol (Avery et al, 1997) were shown to be phase delayed in patients compared with those found in controls. After light therapy, a phase-advance of some of the circadian temperature characteristics (Dahl et al, 1993;Wirz-Justice et al, 1995) and of the secretion of melatonin were observed (Dahl et al, 1993). Neither study revealed disturbances of circadian amplitude.…”

Molecular Clock Genes in Man and Lower Animals Possible Implications for Circadian Abnormalities in Depression

“…SAD affects females more often than males, occurs most frequently between the ages of 20-40 years and may run in families (Rosenthal 1993). Abnormalities in circadian rhythms in SAD include sleep disturbances (Rosenthal et al 1984), increases in the minima of nocturnal core body temperature (Schwartz et al 1997a) and disturbances in cortisol (Avery et al 1997) and melatonin (Dahl et al 1993;Lewy et al 1987Lewy et al , 1998 secretion. In addition, a subgroup of winter depressives have phase-delays reported in temperature, cortisol and melatonin secretion (Dahl et al 1993;Avery et al 1997).…”

Chronobiology, excessive daytime sleepiness and depression: Is there a link?

“…These protocols can certainly contribute to a more accurate understanding of the circadian disruptions that occur in depression, and, thus, can be of substantial value in future research [9]. Table 1 gives an overview of constant routine and forced desynchrony studies in depressed patients [69][70][71][72]67,73].…”