Substance use risk factor for excess mortality in patients with eating disorders

Substance use disorders appeared to increase excess mortality among patients with eating disorders, according to results of a nationwide register-based retrospective cohort study.

“Studies on the impact of [substance use disorders] SUDs on mortality in eating disorders are scarce,” Angelina Isabella Mellentin, PhD, of the Unit for Psychiatric Research at the University of Southern Denmark, and colleagues wrote in American Journal of Psychiatry. “Comorbid alcohol use disorder (AUD) has been found to predict increased all-cause mortality in a pooled sample of patients with eating disorders and patients with [anorexia nervosa]. Conversely, other research has shown no significant association between any comorbid SUD (pooled category) and all-cause mortality in patients with [anorexia nervosa] or [bulimia nervosa].”

The investigators aimed to examine the link between AUDs/other SUDs and mortality in anorexia nervosa, bulimia nervosa and unspecified eating disorder compared with matched control participants. They analyzed data of 20,759 patients with eating disorders and 83,036 matched control participants included in Danish nationwide registers. They calculated HRs to compare all-cause mortality risk between those with eating disorders and control participants both with and without a lifetime diagnosis of SUD.

Compared with controls without SUDs, results showed increased risk for all-cause mortality among patients who abused alcohol and/or cannabis or hard drugs alone or combined with alcohol and/or cannabis. Controls with SUDs had increased risk for all-cause mortality vs. those without SUDs, although to a much lesser degree than patients with an eating disorder and SUD.

“These findings highlight the importance of focusing on the prevention and treatment of SUDs to reduce excess mortality in eating disorder patients,” Mellentin and colleagues wrote. “This is particularly relevant for [anorexia nervosa] patients who abuse hard drugs, since they were found to be the most susceptible to premature death. Interestingly, the driving factor behind mortality in [bulimia nervosa] patients appears to be SUD, and thus the prevention and treatment of SUDs would go a long way toward reducing mortality in [bulimia nervosa].”