OBJECTIVE

To investigate mortality in anorexia nervosa (AN) with a psychiatric comorbidity.

METHODS

Using Swedish registers, data for 8069 female inpatients with AN were retrospectively collected for 1973-2010. Mortality patterns were assessed using standardized mortality ratios (SMRs), Cox regression-derived hazard ratios, and incidence rate ratios. A control cohort of 76,995 women was used.

RESULTS

Patients with AN and a psychiatric comorbidity had higher mortality rates did than those without a comorbidity. The SMRs for patients with AN and a psychiatric comorbidity were 5.4 (95% confidence interval [CI] = 4.6-6.4) and 18.1 (95% CI = 15.2-21.3) for natural and unnatural causes of death, respectively. The SMRs for patients with AN without a comorbidity were 2.8 (95% CI = 2.3-3.5) and 3.1 (95% CI = 2.2-4.1) for natural and unnatural causes of death, respectively. The adjusted hazard ratios for mortality from natural or unnatural causes were 2.0 (95% CI = 1.5-2.7) and 5.7 (95% CI = 3.9-8.2), respectively. Incidence rate ratios comparing patients with AN and controls, both with psychiatric comorbidities, suggest a negative synergistic effect of comorbid AN and psychiatric disorder on mortality, which was greater for unnatural causes of death.

CONCLUSIONS

Mortality in patients with AN was greater in the presence of a psychiatric comorbidity, and even more pronounced for unnatural causes of death and suicides. Substance abuse, especially alcohol use disorder, increased mortality from natural causes of death. These findings highlight the need for early detection and treatment of psychiatric comorbidity in AN, to potentially improve long-term outcomes.