Genetic Factors May Increase Risk of Eating Disorder and Suicide

Tendencies to attempt suicide or to develop an eating disorder may have a linked genetic component, a new study suggests.

Suicide attempts are common in people with eating disorders. In a study in JAMA Psychiatry, Swedish researchers found that that in cases of such attempts, it was likely that other family members were also at risk. Further, the researchers found that the increased risk of suicide attempt in individuals with an eating disorder was not entirely accounted for by having another psychiatric problem.

“These findings suggest that heritable and common risk factors for both eating disorders and suicide attempts may exist and be useful for risk identification,” the researchers found.

They found that increased risk exists in families even when they are not living in the same household, though that risk is lower.

“The pattern of familial coaggregation suggests familial liability for the association between eating disorders and suicide,” Shuyang Yao, MSc and colleagues at the Department of Medical Epidemiology and Biostatistics at Karolinska Institutet, Stockholm, Sweden and colleagues wrote. Coauthors including researchers at the University of North Carolina at Chapel Hill and at Indiana University in Bloomington, IN.

The team used data from Swedish national registers and were able to link individual to their biological full siblings, maternal half siblings, paternal half siblings, full cousins, and half cousins.

They looked at how many subjects had eating disorders, and how many had attempted suicide, or committed suicide.

Of about 2.3 million individuals, 1.4% of all females and 0.09% of all males were recorded as having an eating disorder.

The likelihood of a suicide attempt in these individuals was more than 5 times higher than average, as was the likelihood of successful attempts.

“Individuals who had a full sibling with any eating disorder had an increased risk of suicide attempts,” they concluded, while that risk was attenuated for more distant relatives.

They found similar patterns for two such disorders, anorexia nervosa and bulimia nervosa.

Earlier research has found that both eating disorders and suicide attempts tend to aggregate in families “however, their co-aggregation in families has not been thoroughly explored,” they wrote.

The importance of their findings, they said is that they “suggest that familial risk factors underlie the association between eating disorders and suicide attempts,” and that in some cases there may be genetic factors at work.

“The study represents and important step toward understanding the mechanism underlying the association between eating disorders and suicide, and it encourages future studies to distinguish between genetic and environmental risk factors and examine their interaction,” they concluded.