Weak 24-h periodicity of body temperature and increased plasma vasopressinin melancholic depression

Earlier work has shown that plasma vasopressin levels of depressed patients were higher than those of healthy controls. The aim of the present study w as to determine whether plasma vasopressin levels were correlated to parame ters of the circadian rhythm. Forty-one patients with major depression and twenty-five controls participated in a case-control design under natural ci rcumstances in a field study to investigate plasma vasopressin levels three times daily, circadian motor activity, and the 24-h periodicity of body te mperature for five consecutive 24-h periods. Temperature measurements consi sted of at least five, but mostly six or more measurements every 24 h. Twen ty-two percent of the patients, but none of the controls lacked 24-h period icity of body temperature. In melancholic patients increased vasopressin le vels in plasma correlated with a weak 24-h periodicity of body temperature. The role of vasopressin is discussed in the light of the present findings. (C) 2001 Elsevier Science B.V. All rights reserved.