Substance use disorders (SUDs), particularly alcohol abuse, are linked to excess mortality in patients with eating disorders, new research shows.
The findings, led by Angelina Mellentin, PhD, with the University of Southern Denmark, Odense, showed comorbid SUDs were tied to up to an 11-fold increased risk of death across all eating disorder types.
“Control subjects with SUDs also exhibited an elevated risk of all-cause mortality relative to control subjects without SUDs, although to a much lesser extent than eating disorder patients with SUDs, ” the researchers write.
The study was published online January 1 in The American Journal of Psychiatry.
High Mortality
Eating disorders are associated with high mortality, but the contribution of comorbid SUDs is unclear.
Using Danish nationwide registers, the researchers analyzed data on 20,759 patients with eating disorders.
The cohort included 8108 with anorexia nervosa (AN), 5485 with bulimia nervosa (BN), and 7166 with unspecified eating disorder, as well as 83,036 matched controls without an eating disorder.
The researchers compared all-cause mortality risk between eating disorder patients and controls both with and without a lifetime SUD diagnosis, which included abuse or dependence of alcohol, cannabis, or hard drugs.
Rates of each type of SUD were significantly higher for eating disorder patients than controls (alcohol: 4.7% vs 1.0%; cannabis: 4.3% vs 1.3%; hard drugs: 4.7% vs 1.3%), the researchers report.
Patients with any eating disorder but no SUD had an elevated risk of all-cause mortality (adjusted hazard ratio [aHR]: 2.85), as well as mortality from both external causes (aHR: 3.02) and internal causes (aHR: 2.78), compared with control subjects without an eating disorder or SUD.
SUD comorbidity affected mortality risk in patients with any eating disorder.
Eating disorder patients who abused alcohol, cannabis, hard drugs, or various combinations had a much higher risk of dying from any cause, with hazard ratios ranging from 4.55 to 22.99, than their counterparts with eating disorders and no SUDs.
“Interestingly,” the investigators note, eating disorder patients who abused alcohol alone had a higher risk (aHR: 11.35) than eating disorder patients who abused hard drugs alone (aHR: 4.74) or hard drugs combined with alcohol (aHR: 9.68).
There is consistent evidence that both eating disorders and alcohol use disorder cause “considerable physical damage. Indeed, alcohol has been found to cause more physical damage than certain hard drugs such as cocaine and other stimulants, which may explain our results,” the investigators write.
Controls with SUDs also had an elevated risk of all-cause mortality relative to controls without SUDs, but to a much less extent than eating disorder patients with SUDs.
“These findings highlight the importance of focusing on the prevention and treatment of SUDs to reduce excess mortality in eating disorder patients,” the researchers write.
“This is particularly relevant for AN patients who abuse hard drugs, since they were found to be the most susceptible to premature death,” they note.
In BN, SUD appears to be the “driving factor” behind mortality, “and thus the prevention and treatment of SUDs would go a long way toward reducing mortality in BN,” they add.
A Deadly Combination
Commenting on the study for Medscape Medical News, Kamryn T. Eddy, PhD, co-director of the Eating Disorders Clinical and Research Program, Massachusetts General Hospital, and associate professor, Department of Psychiatry, Harvard Medical School, Boston, said the “findings from this large population-based study support what is well-known in the literature: individuals with eating disorders ― and in particular AN ― are at increased risk for premature death.
“Importantly, these data highlight the most vulnerable group ― that is, those with eating disorders and comorbid alcohol, cannabis, or other drug use disorders,” said Eddy, who wasn’t involved in the study.
The research also shows that the combination of these disorders “can be deadly, and that the risk is additive; that is, having an eating disorder and one substance use problem is bad, but that having two is worse, and three is worse still,” Eddy added.
“For clinicians, these data should absolutely underscore that comprehensive assessment of substance use disorders in those with eating disorders is critical,” Eddy added.
“Clinical research must determine mechanisms, such as impulsivity or altered reward responsiveness, that drive both eating and substance use disorders, which we can address in order to improve treatment effectiveness and save lives,” she said.
Also weighing in, Stephen Wonderlich, PhD, co-chair of the research advisory board, National Eating Disorders Association, said, “The basic finding that substance use disorders contribute substantially to elevated mortality rates in both anorexia nervosa and bulimia nervosa is important.
“I do think that most clinical programs assess reasonably carefully for substance use of various kinds. This study suggests that such screening is even more imperative than we may have thought previously,” said Wonderlich, Chester Fritz Distinguished Professor, Department of Psychiatry and Behavioral Science, University of North Dakota School of Medicine and Health Sciences, in Fargo.
“The take-home message is fairly clear. If an individual has a significant eating disorder and on top of that has a significant substance use disorder, the outcomes are likely to be more negative, including increased risk of death. Clinicians and patients should be aware of this,” Wonderlich added.
This study was supported by the Psychiatric Research Foundation, University of Southern Denmark, Region of Southern Denmark. Mellentin, Eddy, and Wonderlich have no relevant conflicts of interest.
Am J Psychiatry. Published online January 1, 2022. Abstract
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