Suicide and Eating Disorders: New Data

Nancy A. Melville

January 14, 2016

Individuals with eating disorders have been found to be at increased risk for suicide attempts or death by suicide, even after adjustment for psychiatric comorbidities such as depression. The risk is notably increased when a close family member also has an eating disorder, new research shows.

"To our knowledge, this is one of the largest studies investigating the association between eating disorders and suicide attempts and their coaggregation in families," the authors, led by Shuyang Yao, Department of Medical Epidemiology and Biostatistics, Karolinska Institutet, Stockholm, Sweden, write.

Eating disorders have been associated with an increased risk for suicide in previous studies. However, results have been inconsistent, and most studies have been inadequately powered to evaluate the role of psychiatric comorbidities, which can be common with eating disorders, the investigators add.

The current study involved a much larger population ― a Swedish national birth cohort of 2,268,786 individuals born between January 1979 and December 2001 who were followed from the age of six years.

The study was published online January 13 in JAMA Psychiatry.

Risk Identification

The cohort comprised 15,457 females (1.40% of all females) and 991 males (0.09% of males) with eating disorders, including 7680 females (0.70%) and 453 males (0.04%) with anorexia nervosa, and 3349 females (0.30%) and 61 males (0.01%) with bulimia nervosa.

The follow-up showed the risk for a suicide attempt was significantly higher among those with any eating disorder (odds ratio [OR], 5.28, 95% confidence interval [CI], 5.04 - 5.54), as was the risk for death by suicide (OR, 5.39; 95% CI, 4.00 - 7.25; for both, P < .001), compared with those without eating disorders.

After controlling for comorbidities, including major depressive disorder, anxiety disorder, and substance use disorder, the OR was reduced but remained significant for suicide attempts (OR, 1.82; 95% CI, 1.72 - 1.93) and death by suicide (OR, 2.04; 95% CI, 1.49 - 2.80; for both, P < .001) among those with eating disorders.

With regard to suicide attempts and deaths by sicide, the results remained higher after adjusting for psychiatric comorbidities in patients with anorexia nervosa (adjusted OR, 1.70 and 2.67, respectively; for both, P < .001) and bulimia nervosa (adjusted OR, 1.88, P < .001; and 1.48, P = .20).

There were no significant differences between sexes in the risk for attempted suicide or death by suicide before or after adjusting for comorbidities.

"The associations remained significant, suggesting the elevated risks of suicide attempts in eating disorders are not entirely accounted for by psychiatric comorbidity," write the authors, who are based in Sweden and the United States.

Having a full sibling with any eating disorder also increased the risk for suicide attempts (OR, 1.41; 95% CI, 1.29 - 1.53; P < .001).).

The risk was attenuated with more distant relatives, such as maternal half-siblings (OR, 1.10), paternal half-siblings (OR, 1.21), or full cousins (OR, 1.11).

"This finding reveals that the association between eating disorders and suicide is influenced by familial risk factors," the authors write.

Regarding the role of familial influence on the increased risk, the authors note that the risk appears more a result of genetic factors as opposed family environment, because if the causative factor was environmental, then higher ORs would be expected in maternal half-siblings than paternal half-siblings, owing to genetic sharing, but that pattern was not observed.

"By comparing the ORs across different types of relatives, our design allowed deeper exploration of the origin of the familial liability," they write.

"These results suggest that heritable and common risk factors for both eating disorders and suicide attempts may exist and be useful for risk identification," they add.

The findings underscore that eating disorders can truly be life-threatening, Yao told Medscape Medical News.

"Clinicians and family members should remain vigilant for signs of suicidality in all individuals with eating disorders — regardless of the presence of other psychiatric disorders. Risk for suicide was increased in both anorexia and bulimia nervosa, encouraging vigilance in both disorders," she added.

Important Contribution

With a pressing need for a better understanding of the relationship between eating disorders and premature mortality, the study is an important contribution, Kamryn T. Eddy, PhD, codirector of the Eating Disorders Clinical and Research Program, Massachusetts General Hospital, and associate professor, Department of Psychiatry, Harvard Medical School, Boston, told Medscape Medical News.

"Risk of premature mortality in eating disorders, particularly by suicide, is among the highest of any psychiatric illness, making it critical that we understand in whom, when, and why is risk greatest," she said.

"That the association between eating disorders and suicidality is only partly explained by psychiatric comorbidity suggests that there may be important latent variables accounting for this shared risk in need of study: genes, neurobiology, personality represent candidate variables in need of study."

The findings suggest the need for heightened attention to the various risk factors for suicide in the management of eating disorders, Dr Eddy added.

"From a suicide prevention standpoint, these findings underscore the importance of longitudinal safety assessment in those with eating disorders, and also of routinely ascertaining family psychiatric history in all patient care."

The study received funding through a scholarship from the China Scholarship Council and from the American Foundation for Suicide Prevention, the Swedish Initiative for Research on Microdata in the Social and Medical Sciences framework, the Swedish Research Council, and the Global Foundation for Eating Disorders. One coauthor has served as a speaker for Eli Lilly. Dr Eddy has disclosed no relevant financial relationships.

JAMA Psychiatry. Published online January 13, 2015. Abstract

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