Stress Exposure, Psychological Distress, and Physiological Stress Activation in Midlife Women With Insomnia JOAN L. F. SHAVER,PHD, RN, FAAN, SANDRA K. JOHNSTON, MS, RN, MARTHA J. LENTZ,PHD, RN, AND CAROL A. LANDIS, DNSC, RN Objective: The objective of this study was to describe perceived and polysomnograhic (PSG) sleep patterns and determine whether stress exposure, psychological distress, and physiological stress activation differed among midlife women with psychophysiologic-type (PP-type) or subjective only-type (SO-type) insomnia or no insomnia. Methods: Women had their sleep monitored, collected urine samples, and completed questionnaires in a week-long field study, and 53 women met criteria for insomnia types or no insomnia based on reported sleep quality and PSG sleep efficiency. Results: As expected, women with PP-type insomnia were found to have the lowest sleep efficiency, took longer to fall asleep, had more wakefulness after sleep onset, and had more fragmented sleep. Perceptions of stress exposure, either for major or minor events, did not differ among groups. Despite there being no differences in perceived stress exposure, women with both types of insomnia scored higher on psychological distress (SCL-90R), especially on the somatization subscale, than women with no insomnia. Of the physiological stress activation indicators tested, a morning-to-evening difference in urinary cortisol statistically differed across the groups (p  .005). Women in the PP-type insomnia group had the highest levels of urinary cortisol in an early morning urine sample. Conclusions: These data provide support for the hypothesis that, in midlife women, cognitive or emotional arousal with chronic stress neuroendocrine activation underlies chronic insomnia, partic- ularly the PP-type. Key words: insomnia, stress exposure, psychological distress, stress hormones. PSG = polysomnograph/polysomnography; PP-type = psychophysiologic type; PTSD = posttraumatic stress disorder; MMPI = Minnesota Multiphasic Personality Inventory; SO-type = subjective-only type; SCL = Symptom Checklist; REM = rapid eye movements; NREM = nonrapid eye movements; SWS = slow-wave sleep; SPT = sleep-period time, TIB = time in bed; SCL-90R = Symptoms Checklist—90 items, revised; WASO = wake after sleep onset; TST = total sleep time; SEI = sleep efficiency index; BMI = body mass index. INTRODUCTION Explanatory ideas about chronic insomnia (per- ceived poor quality or insufficient sleep) incorporate concepts of psychological arousal or distress, includ- ing a propensity to internalize anxiety. In an epidemi- ologic survey, people with insomnia reported symp- toms consistent with anxiety and depression (1). People with chronic insomnia have shown more dys- phoria than those without insomnia (2, 3). They have scored above the norm on the rumination, anxiety, inhibition of emotion, and inability to discharge anger outwardly and have tended toward high neuroticism and introversion scores on the subscales of the MMPI (4). People with chronic insomnia have been charac- terized by a pattern of internalization of problems combined with an anxious-depressive reaction style (5). Bedtime state anxiety has been positively related to perceived sleep latency (6), and negative emotions, stress responsiveness, and attention factors were found to influence particular types of insomnia, ie, sleep-onset vs. maintenance insomnia (7). Chronic in- somnia appears to be a function of heightened emo- tional distress, but whether or not the distress ema- nates from the extent of perceived stress exposure or to ongoing stressful circumstances remains unclear. Stressful conditions, especially emotionally pro- found ones, have been consistently linked to evidence of disturbed sleep patterns, either perceived or corrob- orated by PSG. Often, this is short term and is labeled acute or transient insomnia. Perceptions of poor sleep quality have been reported in people coping with the Three Mile Island nuclear incident (8), in parents cop- ing with malignant disease in their children (9), and in victims after Hurricane Andrew (10). Increased PSG sleep fragmentation was observed in subjects after Hurricane Andrew (10). Women undergoing divorce, depressed or not, displayed shorter REM latency, more REM percent time, and lower delta wave (slow-wave) sleep patterns compared with control women as long as the divorce status remained unresolved (11). Enduring or everyday stress, often studied in rela- tion to occupational demands, has been linked with insomnia. For example, female construction workers with perceived job uncertainty and need to overcom- pensate at work had high reports of insomnia (12). From the Department of Medical Surgical Nursing (J.L.F.S.), Uni- versity of Illinois at Chicago, Chicago, IL and Department of Biobe- havioral Nursing and Health Systems (S.K.J., M.J.L., C.A.L.), Univer- sity of Washington, Seattle, WA. Address reprint requests to: J. L. Shaver, Professor and Dean, Uni- versity of Illinois at Chicago, College of Nursing M/C 802, 845 South Damen Avenue, Chicago, IL 60612-7350. Email: jshaver@uic.edu Received for publication November 28, 2000; revision received October 22, 2001. DOI: 10.1097/01.PSY.0000024235.11538.9A 793 Psychosomatic Medicine 64:793– 802 (2002) 0033-3174/02/6405-0793 Copyright © 2002 by the American Psychosomatic Society