Anorexia nervosa has been found to increase mortality risk by 4.5-fold. This number is doubled with psychiatric comorbidities.
"The risk of dying from unnatural causes was higher than dying from natural causes. The association between [anorexia] and unnatural deaths was primarily driven by a high risk of suicide with a further three-fold increased risk in patients with [anorexia] and psychiatric comorbidity," noted study investigators
The nationwide population-based cohort study published in the International Journal of Eating Disorders, investigated overall and cause-specific mortality in 14,414 patients with anorexia nervosa in Denmark from 1977 to 2018. The authors compared the cohort to a 1:10 age- and sex-matched general population cohort. Median age at diagnosis was 18.5 years, and 93.5% of the anorexia nervosa cohort were female. The median follow-up time was 9 years.
Using Cox proportional hazard models, the authors found a weighted average adjusted hazard ratio (aHR) for all-cause mortality of 4.5 (95% CI, 4.1-4.9) in patients with anorexia nervosa, with the highest risk in the first 10 years after diagnosis (aHR, 6.9; 95% CI, 6.2-7.8). Psychiatric comorbidities were present in 46.9% of the anorexia nervosa cohort at the index date, compared to 8.0% in the general population cohort. The most common psychiatric comorbidities in the anorexia nervosa cohort were neurotic, stress-related, and somatoform disorders (20.5%), mood disorders (14.7%), and behavioral and emotional disorders with onset usually occurring in childhood and adolescence, including ADHD (17.9%).
Patients with anorexia nervosa and psychiatric comorbidities had an aHR for all-cause mortality of 7.7 (95% CI, 6.7-8.9), while those without comorbidities had an aHR of 5.2 (95% CI, 4.1-6.5), compared to the general population. When comparing the two anorexia nervosa groups, the aHR for mortality was 1.9 (95% CI, 1.5-2.4) for those with psychiatric comorbidities. The impact of psychiatric comorbidities on mortality was most pronounced in patients diagnosed with anorexia nervosa at ages 6-14 years (aHR, 9.7; 95% CI, 4.4-21.6) and 15-25 years (aHR, 11.3; 95% CI, 7.9-16.0).
Mortality risk was similar between males (10-year aHR, 4.5; 95% CI, 3.5-5.8) and females (10-year aHR, 4.0; 95% CI, 3.7-4.3) with anorexia nervosa. The aHR for all-cause mortality was highest in patients diagnosed with anorexia nervosa between 1977-1994 (aHR, 10.5; 95% CI, 8.5-13.0) and decreased in subsequent periods, with no significant difference between 1995-2006 (aHR, 5.8; 95% CI, 4.9-6.9) and 2007-2018 (aHR, 5.7; 95% CI, 4.5-7.1).
"Our results stress the importance of early intervention and specialized treatment to detect and treat psychiatric comorbidities alongside the eating disorder to prevent fatal outcomes especially with focus on the first years after diagnosis and on those diagnosed at younger age," investigators concluded.
They declared having no competing interests.