Slow-wave activity in NREM sleep sex and age effects in….pdfVIP

Psychiatry Research 95 2000 201 213 Slow-wave activity in NREM sleep: sex and age effects in depressed outpatients and healthy controls Roseanne Armitage , Robert Hoffmann, Madhukar Trivedi, A. John Rush Department of Psychiatry, Uniersity of Texas Southwestern Medical Center, 5323 Harry Hines Bouleard, Dallas, TX 75390-9070, USA Received 18 January 2000; received in revised form 19 May 2000; accepted 23 May 2000 Abstract The amplitude and time course of slow-wave activity SWA during NREM sleep were compared in 76 outpatients with depression and 55 healthy control subjects. Lower SWA amplitude was evident in the depressed group, especially among depressed men. For the most part, significant differences between patients and control subjects were restricted to the first NREM period and only in those 20 30 years of age. Significant age-related declines in SWA amplitude were evident in control subjects but not in depressed patients. In addition, sex differences in the depressed group were twice as large as those seen in control subjects. The time course of SWA amplitude, presumed to reflect homeostatic sleep regulation of SWA, was only abnormal in depressed men with lower accumulation and slower dissipation over NREM sleep. Depressed women showed no evidence of an abnormal SWA time course. Furthermore, no sex differences in the time course of SWA were evident in control subjects, and age-related changes in this aspect of regulation were not striking in any group. Thus, the amplitude of SWA showed strong age effects in healthy individuals but not in those with MDD whereas the time course sh