Mental vulnerability as a predictor of early mortality

BACKGROUND: Studies have demonstrated that mental vulnerability (ie, a tendency to experience psychosomatic symptoms or inadequate interpersonal interactions) is associated with various diseases. The objective of our study is to evaluate whether mental vulnerability is a risk factor for early mortality.

METHODS: We conducted a prospective cohort study of 3 random samples of the population in Copenhagen County, Denmark selected in 1976, 1982-1984, and 1991 (n = 6435). Baseline data collection included measures of mental vulnerability, social factors, comorbidity, biologic risk markers (eg, blood pressure, lipid levels), and lifestyle factors. We determined vital status of the study sample through linkage to the Civil Registration System until 2001 and to the Cause of Death Registry until 1998. The mean follow-up time was 15.9 years for analysis of total mortality and 13.6 years for analysis of mortality as the result of natural causes. The association between mental vulnerability and survival was examined using Kaplan-Meir plots and Cox proportional-hazard models adjusting for possible confounding factors.

RESULTS: With respect to mental vulnerability, 79% of the sample was classified as not vulnerable, 13% as moderately vulnerable, and 8% as highly vulnerable. Compared with the nonvulnerable group, highly vulnerable persons showed increased total mortality (hazard ratio = 1.6; 95% confidence interval = 1.3-1.9) and increased mortality from natural causes (1.6; 1.2-2.0). The inclusion of the mental vulnerability score as a continuous variable gave similar results.

CONCLUSIONS: Mental vulnerability may be an independent risk factor for premature mortality. The biologic mechanisms that may underlie this association need further exploration.