The relationship of stress, sleep, and depression in an elderly cohort: Predictors, mediators, and moderators

• Main Author: Anderson, Barbara P
• Format: Dissertation
• Language: English
• Published: ProQuest Dissertations & Theses 01-01-1999
• Subjects: Clinical psychology; Gerontology; Psychobiology; Psychotherapy; Public health
• ISBN: 9780599469570; 0599469579

The purpose of this study was to examine widowhood as a prototypical life stressor, in order to investigate the relationship between life stress, sleep, and depression in an elderly cohort. It was proposed that sleep may be one of the biological factors mediating the effects of stress on depression. The moderation of these stress effects by other psychosocial factors was also examined. In order to examine these relationships, a cohort of bereaved (n = 99) and non-bereaved elders (n = 72) without a history of depression prior to bereavement were studied. Baseline and one year follow-up data were examined in a series of cross-sectional and longitudinal analyses. Results indicated that loss of spouse was a significant and potent risk factor for depressive outcomes in the sample; the one-month and six-month incidence rates of major depression were estimated to be 28.6% and 53.2%. While it appears that the majority of bereaved elders adapted well to the loss of their spouse, for a significant minority of elders (i.e., 18%), the symptoms of major depression remained evident at approximately 18 months post-loss. Level of grief was a key characteristic of the bereavement experience that significantly predicted depressive outcomes. Subjective sleep quality partially mediated or accounted for, the link between bereavement and depression; this mediation process via subjective sleep quality was generally not moderated by other psychosocial variables. Nevertheless, a variety of psychosocial variables, including anxiety, social support, and positive life events, emerged as independent predictors in their own right of depressive outcomes. Moreover, these psychosocial variables moderated the portion of the bereavement-depression linkage that could not be explained by sleep quality. The present study extends previous bereavement and life stress research by documenting the robust effect of widowhood on the onset of incident major depression in physically and psychiatrically healthy elders. The elucidation of factors that either increase vulnerability in the aftermath of a negative life event—or exert protective effects—may allow for the early identification of elders at greater risk and/or inform clinical and therapeutic interventions.