Temperature rhythm of patients with major affective disorders: reduced circadian period length.

The aim of the study was to explore circadian alterations of the temperature rhythm in adults with Major Affective Disorders (DSM III-R:296.xx). The axillary temperature of 56 inpatients was recorded (6-min intervals for at least a 48-h span) when major clinical symptoms occurred and thereafter during the remission. Periods (tau s) of the temperature rhythm were accurately quantified from individual time series by power spectra analyses. Twenty-seven subjects with no affective disorders served as controls. Histograms of the frequency distribution of tau s, chi square, and so forth were used as statistical methods. In both patients and controls a multimodal distribution of prominent tau s was observed. However, in controls this distribution showed the highest frequency (88.9%) with tau s = 24h, and seldom tau s < 24h or tau s > 24h, while in patients with major affective disorders, tau s exhibited a statistically significant (x2 = 10.84; p < 0.004) different distribution with the highest frequency for tau s < 24h in 50% of the patients. Subjects diagnosed as suffering from Major Affective Disorders commonly exhibit a period shorter than 24h in the axillary temperature circadian rhythm suggestive of a desynchronized time structure.