Strong Link Found Between Anxiety, Eating Disorders

Anxiety has been known for some time to be common in people with an eating disorder. But a new study suggests that anxiety often precedes—in fact, may even be a predisposition to—eating disorders.

This finding “may be surprising to people,” Walter Kaye, M.D., a professor of psychiatry at the University of Pittsburgh, told Psychiatric News.

Kaye was the chief author of the study, which appears to be the largest to date on the co-occurrence of anxiety disorders and eating disorders. Results appeared in the December American Journal of Psychiatry.

Kaye and his coworkers gave the Structured Clinical Interview for DSM-IV Axis I Disorders, as well as standardized tests for anxiety, perfectionism, and obsessionality, to 672 subjects with an eating disorder (97 individuals with anorexia nervosa, 282 with bulimia nervosa, and 293 with both anorexia and bulimia).

Some two-thirds of the subjects, it turned out, had had one or more anxiety disorders at some point in their lifetimes, a much higher rate than that found in mentally healthy women in the community by other researchers (between 13 percent and 31 percent).

The most common anxiety disorders experienced by these subjects were obsessive-compulsive disorder (41 percent) and social phobia (20 percent).

Even more striking, most of the subjects who reported an anxiety disorder said that they had developed it in childhood, before they had acquired an eating disorder.

Thus, childhood anxiety may not just herald the later onset of eating illnesses but may actually predispose to them, Kaye and his coworkers concluded in their study report.

Nonetheless, it is probably not anxiety per se, but the inheritance of anxiety traits that makes a person vulnerable to the development of eating ailments, Kaye pointed out. “While many people diet and are concerned about weight in our culture, relatively few develop an eating disorder. Thus there may be certain traits that make some people particularly vulnerable.”

Also, since there is growing evidence that eating disorders have a genetic input (Psychiatric News, June 4, 2004), and since anxiety disorders appear to often precede eating disorders, the same genes that predispose to anxiety illnesses may also set the stage for eating disorders, Kay suspects. In fact, he and his colleagues have some preliminary evidence that certain genetic regions implicated in anxiety are also implicated in eating disorders.

Moreover, because of the purportedly close link between anxiety illness genes and eating disorder genes, Kay conjectured, eating disorders “may be a strategy that some people use to reduce anxiety. That is, extreme eating may blunt anxious feelings.”

“The finding that anxiety disorder commonly precedes the diagnosis of the eating disorder should [also] generate additional investigations on prevention/early intervention strategies addressing anxiety disorders,” David Herzog, M.D., said in an interview. Herzog is head of the Harvard Eating Disorders Center at Massachusetts General Hospital.

Kaye concurred. “Teaching children with these traits better coping strategies for anxiety might reduce the incidence of eating disorders.”

The investigation was funded by the Price Foundation, a private foundation based in Europe.

The study, “Comorbidity of Anxiety Disorders With Anorexia and Bulimia Nervosa,” is posted online at<http://ajp.psychiatryonline.org/cgi/content/full/161/12/2215?>.▪

Am J Psychiatry 2004 161 2215