Background. Mental disorders have an increased mortality risk. However, most data have been provided by few countries, some mental disorders have received little attention, long-term studies of large samples are scarce, and insufficient control for confounding variables has lead to artefactual inconsistencies across studies. The aims of this study were: to quantify the mortality risk in psychiatric patients 5 to 21 years after hospital admission and to investigate temporal trends in mortality risk and predictive factors associated with mortality.

Method. All patients admitted to an in-patient psychiatric unit in Italy between 1978 and 1994 were included and vital status and death causes were determined up to 21 years after admission. The observed number of deaths in the sample was compared with the expected number of deaths in the general population. Cox proportional hazard models were fitted to identify predictors of mortality.

Results. Mortality from natural and unnatural causes was higher than expected across all mental disorders. Standardized mortality risk was higher in males (SMR = 4·55; 95% CI 4·17–4·97) than in females (SMR = 3·43; 95% CI 3·07–3·83). Individuals aged less than 40 years were at higher risk in both sexes. The first several years following admission were characterized by a faster decline in survival. Several demographic and clinical factors were predictors of mortality.

Conclusions. Mortality is high in individuals with mental disorders. Prevention of unnatural death causes is an important goal though insufficient to abate excess mortality, since natural death causes account for it to a larger extent.