Nocturnal and circadian body temperatures of depressed outpatients during symptomatic and recovered states

Abstract

Forty-one recurrent unipolar depressed outpatients were studied at baseline (symptomatic period) and at recovery. Rectal temperatures were measured continously between 1800h and 0600h on 2 successive nights at each time point. In those 24 patients who recovered after receiving interpersonal psychotherapy (IPT) alone (“psychotherapy responders”) and who thus remained drug-free throughout, there was no difference in nocturnal body temperatures between baseline and recovery time points. Moreover, noctrunal temperatures patterns appeared to be very similar to those of a healthy contrast group ( n=17). The contrast group was not matched for age and gender with the patient group, though, so the comparison was only suggestive. At baseline, those recovering after psychotherapy alone ( n=24) did not differ from those eventually failing to respond to IPT and requiring medications to achieve recovery (“medication responders”) ( n=17). Medication responders did show some baseline versus recovery differences in nocturnal temperatures, but these may possibly have been a function of the medications used. At recovery, a subset of 19 psychotherapy responders and 13 medication responders underwent an “unmasking” experiment involving 36 hours of wakeful bedrest. In the resulting endogenous temperature rhythms, there was no evidence of any reliable differences between the psychotherapy responder and medication responder patient groups. Both groups showed rhythms that were very similar to those of a healthy contrast group ( n=17), although, again, the contrast group was not matched for age or gender with the patient group. In conclusion, in measures of body temperature, at least, there appeared to be little evidence of circadian dysfunction in this group of recurrent outpatient depressives.