Body temperature and mood variations during forced desynchronization in winter expression: A preliminary report

Background: It has been suggested that certain abnormalities (e.g., in phas e or amplitude) of the circadian pacemaker underlie seasonal affective diso rder, Methods: One male seasonal affective disorder patient (blind to the study: design) participated in two 120-hour forced desynchrony experiments and tva s subjected to six 20-hour days, once during a depressive episode and once after recovery. Core body temperature was continuously measured. During wak efulness, the Adjective Mood Scale was completed at 2-hour intervals, Results: Sleep-wake as well as pacemaker-related variations of mood were fo und, both when the subject was depressed and when he was euthymic. Compared with recovery, during the depressive episode the circadian temperature min imum 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, pa rticipating in forced desynchrony experiments, malt indicate a phase delay of the circadian pacemaker during a seasonal affective disorder episode, Bi ol Psychiatry 2000;47:355-358 (C) 2000 Society of Biological Psychiatry.