Background: Emerging research is beginning to uncover a high prevalence of modifiable risk factors in patients with severe mental illness. We examined whether the association between episodes of psychiatric illness that involved hospitalization and all-cause mortality is mediated by behavioral risk factors.
Methods: Data were collected from a nationally representative sample of 19 898 men and women from the Scottish Health Surveys (1995, 1998, and 2003) that were linked to a patient-based database of hospital admissions and deaths up to September 2006. There were 597 participants with at least 1 hospital admission for a psychiatric episode.
Results: During a mean follow-up of 8.5 years, participants with a history of a psychiatric episode had a higher risk of all-cause mortality (age- and sex-adjusted hazard ratio, 3.25; 95% confidence interval, 2.63-4.02). In addition, they were more likely to be heavy smokers (odds ratio, 4.69; 95% confidence interval, 3.79-5.82), have low physical activity levels (2.24; 1.75-2.87), come from a lower socioeconomic group (2.17; 1.72-2.72), and be separated or divorced from their partner (2.02; 1.63-2.52). In multivariate analyses, the association between history of a psychiatric episode and all-cause mortality was attenuated but remained statistically significant (hazard ratio, 2.02; 95% confidence interval, 1.62-2.52; P<.001) after adjustments for psychosocial factors, smoking, physical activity, body mass index, and current mental health.
Conclusions: Behavioral risk factors may partly mediate the association between psychiatric episodes and mortality. These data highlight the need for prevention and treatment strategies among individuals with a history of severe mental illness.