Psychological distress, physical illness and mortality risk.

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.