پریشانی روانی، بیماری جسمی و خطر مرگ

Background Psychological distress has been associated with an increased risk of overall and disease-specific mortality risk. This study examines whether the length of follow-up time influences mortality risk. Methods The associations between psychological distress and all-cause and coronary heart disease mortality were modelled using proportional hazards modelling in a prospective cohort study of 6920 men and women aged 45–64 years. Psychological distress was assessed at baseline using the 30-item General Health Questionnaire (GHQ-30). Results Psychological distress was associated with a 5-year all-cause mortality (RR 1.68 95% CI 1.07–2.62) and CHD mortality (RR 1.64 95% CI 1.02–2.56) in men after adjustment for sociodemographic and CHD risk factors, but not after further adjustment for baseline physical illness (RR 1.41 95% CI 0.88–2.23) for all-cause mortality (RR 1.39 95% CI 0.88–2.21) for CHD mortality. Psychological distress was not associated with all-cause and CHD mortality at 15- and 20-year follow-up. Conclusions Psychological distress is a reflection of baseline physical illness that increases mortality risk. Psychological distress maybe on the causal pathway between physical illness and mortality risk.

Psychological distress has been found to predict mortality in community populations [1], [2], [3], [4] and [5]. An association has also been found using depressive illness classified by DSM-III criteria [6] and self-reports of major depression [7]. The association between psychological distress and increased risk of mortality has also been found for scales measuring depressive symptoms, e.g., CES-D Scale [2], [3], [8], [9], [10] and [11], the Geriatric Depression Scale [12], and for nonspecific screening questionnaires for psychological distress like the 30-item General Health Questionnaire (GHQ-30) [5]. In this study, psychological distress was associated with a 64% increased risk of 7 years mortality in men and 58% increased risk in women, after full adjustments for sociodemographic smoking and physical illness. Psychological distress has also been found to predict disease-specific mortality, particularly CHD mortality [8], [13] and [14]. Recent investigations have suggested a differential effect in men and women of depressive symptoms on CHD incidence [15] and mortality; distressed men had over twice the risk of CHD mortality than nondistressed men, but distress was not associated with CHD mortality in women [8]. In studies that have found an association between psychological distress and all-cause and disease-specific mortality risk, the follow-up period over which this is evident is unclear. Some studies find that psychological distress is associated with 4–7 years all-cause mortality risk [3], [5] and [11], while others find an association between psychological distress and all-cause mortality after 10 years of follow-up [8]. The interval between psychological distress and mortality has implications for the mechanism of this association. A short interval is in keeping with explanations either related to psychological distress at baseline being related to subclinical physical ill health, which independently predicts mortality, or to short-term effects of psychological distress on coronary heart disease risk mediated through increased risk of thrombosis, arrhythmias or inflammation. A longer interval between psychological distress and mortality would support aetiological explanations based on psychological distress having long-term influences on risk factors such as smoking or through pathophysiological processes such as atherogenesis. The aim of this investigation was to examine the association between psychological distress and all-cause and CHD mortality in men and women followed up for 20 years in the Renfrew and Paisley study; to examine whether length of follow-up time influences the mortality risk associated with psychological distress.

Psychological distress was associated with an increased risk of all-cause and CHD mortality in men only after adjustment for sociodemographic and CHD risk factors but not after further adjustment for baseline physical illness. In terms of the causal pathway, this suggests that psychological distress is either on the causal pathway between physical ill health and mortality risk or is an indicator of physical illness that independently carries increased risk of mortality.