Restless sleep, illness intrusiveness, and depressive symptoms in three chronic illness conditions: rheumatoid arthritis, end-stage renal disease, and multiple sclerosis.

Restless sleep was compared across 110 out-patients with rheumatoid arthritis (RA), 101 with end-stage renal disease (ESRD), 94 with multiple sclerosis (MS), and an unselected control group of 176 individuals attending their family practitioners (FP). It was also investigated in the three chronic illness groups as a contributor to illness intrusiveness--the extent to which one's illness and/or its treatment interfere with continued involvements in valued activities and interests--a determinant of depression and emotional distress in chronic conditions. Reported frequencies of restless sleep were highest in RA, lower in ESRD, and lowest in MS; FP patients reported frequencies that were similar, overall, to those observed in MS. These differences were evident among nondepressed, (chi 2 9, N = 309, p < 0.0001), but not depressed, individuals. The occurrence of restless sleep correlated significantly with increased illness intrusiveness, r (279) = 0.31, p < 0.001, in RA, ESRD, and MS. Results supported the hypothesis that the relation between restless sleep and emotional distress is mediated by illness intrusiveness. Treatment of restless sleep may offer the added benefit of diminishing illness intrusiveness and may, thereby, enhance quality of life in chronic physical illness.