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

In healthy subjects, both the duration of wakefulness and the circadian pacemaker have been demonstrated to be involved in the regulation of mood. Some features of affective disorders suggest that these two factors also play a role in the dysregulation of mood. In particular, disturbances of the circadian pacemaker have been proposed to be a pathogenetic factor in Seasonal Affective Disorder, winter type (SAD). This report presents a test of this proposition. To this end seven SAD patients and matched controls were subjected to a 120-h forced desynchrony protocol, in which they were exposed to six 20-h days. This protocol enables us to discriminate the extent to which the course of mood is determined by the imposed 20-h sleep–wake cycle from the influence of the circadian pacemaker on that course. Patients participated during a depressive episode, after recovery upon light therapy and in summer. Controls were studied in winter and in summer. Between SAD patients and controls no significant differences were observed in the period length nor in the timing of the endogenous circadian temperature minimum. In both groups, sleep–wake cycle- and pacemaker-related components were observed in the variations of mood, which were not significantly different between conditions.

A Forced Desynchrony Study of Circadian Pacemaker Characteristics in Seasonal Affective Disorder

The circadian pacemaker is an endogenous clock that regulates oscillations in most physiological and psychological processes with a near 24-h period. In many species, this pacemaker triggers seasonal changes in behavior. The seasonality of symptoms and the efficacy of light therapy suggest involvement of the circadian pacemaker in seasonal affective disorder (SAD), winter type. In this study, circadian pacemaker characteristics of SAD patients were compared with those of controls. Seven SAD patients and matched controls were subjected to a 120-h forced desynchrony protocol, in which core body temperature and melatonin secretion profiles were measured for the characterization of circadian pacemaker parameters. During this protocol, which enables the study of unmasked circadian pacemaker characteristics, subjects were exposed to six 20-h days in time isolation. Patients participated twice in winter (while depressed and while remitted after light therapy) and once in summer. Controls participated once in winter and once in summer. Between the SAD patients and controls, no significant differences were observed in the melatonin-derived period or in the phase of the endogenous circadian temperature rhythm. The amplitude of this rhythm was significantly smaller in depressed and remitted SAD patients than in controls. No abnormalities of the circadian pacemaker were observed in SAD patients. A disturbance in thermoregulatory processes might explain the smaller circadian temperature amplitude in SAD patients during winter.

Sleep in seasonal affective disorder patients in forced desynchrony: an explorative study

The majority of winter-type seasonal affective disorder (SAD) patients complain of hypersomnia and daytime drowsiness. As human sleep is regulated by the interaction of circadian, ultradian and homeostatic processes, sleep disturbances may be caused by either one of these factors. The present study focuses on homeostatic and ultradian aspects of sleep regulation in SAD. Sleep was recorded polysomnographically in seven SAD patients and matched controls subjected to a 120-h forced desynchrony protocol. In time isolation, subjects were exposed to six 20-h days, each comprising a 6.5-h period for sleep. Patients participated while being depressed, while remitted after light therapy and in summer. Controls were studied in winter and in summer. In each condition, the data of each subject were averaged across all recordings. Thus, the influence of the effects of the circadian pacemaker on sleep was excluded mathematically. The comparison of patients with controls and with themselves in the various conditions revealed no abnormalities in homeostatic parameters: sleep stage variables, relative power spectra and time courses of power in various frequency bands across the first three non-rapid eye movement–rapid eye movement (NREM–REM) cycles showed no differences. The data suggest that homeostatic processes are not involved in the disturbance of sleep in SAD.

Body Temperature and Mood Variations during Forced Desynchronization in Winter Depression: A Preliminary Report

Background: It has been suggested that certain abnormalities (e.g., in phase or amplitude) of the circadian pacemaker underlie seasonal affective disorder. Methods: One male seasonal affective disorder patient (blind to the study design) participated in two 120-hour forced desynchrony experiments and was subjected to six 20-hour days, once during a depressive episode and once after recovery. Core body temperature was continuously measured. During wakefulness, the Adjective Mood Scale was completed at 2-hour intervals. Results: Sleep–wake as well as pacemaker-related variations of mood were found, both when the subject was depressed and when he was euthymic. Compared with recovery, during the depressive episode the circadian temperature minimum and the circadian mood variation showed phase delays of approximately 1 and 2 hours, respectively. Conclusions: The data of this first seasonal affective disorder patient, participating in forced desynchrony experiments, may indicate a phase delay of the circadian pacemaker during a seasonal affective disorder episode.

Chapter 7 - Acute psychiatric illness and drug addiction during pregnancy and the puerperium

Pregnancy and the puerperium do not protect against acute psychiatric illness. During puerperium, the chance of acute psychiatric illness, such as a psychotic episode or relapse of bipolar disorder, is greatly increased. Suicide is a leading cause of maternal death. Both psychiatric disease and ongoing drug addiction impact not only the pregnant woman's somatic and mental health but also impact short-term and long-term health of the child. Indeed, prompt recognition and expeditious treatment of acute psychiatric illness during pregnancy and the puerperium optimize health outcomes for two patients. Pregnancy and puerperium represent a stage of life of great physiologic adaptations, as well as emotional and social changes. This conjunction of changes in somatic, emotional health and social health may mitigate the occurrence, clinical presentation, and clinical course of acute psychiatric illness and call for a multidisciplinary approach, taking into account both the medical and social domains. This chapter describes acute psychiatric illnesses during pregnancy and the puerperium and illicit substance abuse, from a clinical perspective, while also describing general principles of diagnosis and clinical management during this stage of life, which is an important window of opportunity for both the pregnant woman and the child

Extraocular Light Therapy in Winter Depression: A Double-blind Placebo-controlled Study

Background: It has been hypothesized that the circadian pacemaker is phase delayed in seasonal affective disorder, (SAD) winter type, and that the phase advance resulting from morning ocular light accounts for the efficacy of light therapy. Extraocular light has been reported to produce phase-shifts of the human circadian pacemaker. This allows a double-blind, placebo-controlled study of light therapy in SAD. Methods: Twenty-nine SAD patients participated. Clinical state was measured on days 1, 8, and 15 of the protocol. From days 4 through 8, 15 patients (4 M, 11 F) received extraocular light by fiberoptic illumination, and 14 (4 M, 10 F) placebo (no light) in the popliteal fossae, from 8 AM to 11 AM. In the evenings of days 3 and 8, the salivary dim light melatonin onset (DLMO) was assessed. Patients completed daily self-ratings on mood, alertness, and sleep. Results: Both conditions showed a progressive improvement of clinical state over time. Between conditions, no significant differences were observed in clinical scores, the self-ratings on mood and alertness, and in timing of the DLMO before and directly after treatment. Conclusions: The response to extraocular light therapy in SAD patients did not exceed its placebo effect. Extraocular light did not induce a phase shift of the circadian pacemaker.