By Marilynn Larkin
NEW YORK—Hospital-treated and anti-infective-treated infections are associated with an increased risk of anorexia nervosa, bulimia nervosa, and eating disorders not otherwise specified (EDNOS), such as binge eating, in adolescent girls, researchers say.
"These relationships appear to be both time- and dose-dependent, meaning that the onset of eating disorder diagnosis is greatest in the first three months following the infection, and the more infections, the greater the risk," said Lauren Breithaupt of Massachusetts General Hospital in Boston. "Both neuroinflammation and pathogens may be at play."
"Commonly reported symptoms of both infections and inflammation include loss of appetite and decreased food intake," said Breithaupt, who was at George Mason University in Fairfax, Virginia during the study. "Changes in microbiota from infections or ingestion of anti-infective agents could affect behaviors via communication from the gut-brain axis (i.e., via the vagus nerve)."
However, she added, "It is important to note that the majority of kids with a common infection will not go on to develop an eating disorder, and infections themselves are necessary for adolescents for the normal development of the immune system."
Breithaupt and colleagues studied more than half a million adolescent girls in a Danish registry, followed for more than four million person-years until a mean age of 16.
As reported online April 24 in JAMA Psychiatry, more than 4,000 (0.8%) were diagnosed with an eating disorder: 2,131 with anorexia nervosa (median age, 15.2), 711 with bulimia nervosa (median age, 17.9), and 1,398 with EDNOS (median age, 15.6).
Compared with girls not hospitalized for infection, for those who were, severe infections were associated with a 22% increased risk of a subsequent diagnosis of anorexia, (hazard ratio, 1.22), a 35% increased risk of bulimia (HR, 1.35), and a 39% increased risk of EDNOS (HR, 1.39) compared with those without hospitalizations for infections.
Similarly, infections treated with three or more anti-infective agents were associated with a 23% increased risk of a subsequent diagnosis of anorexia (HR, 1.23;), a 63% increased risk of bulimia (HR, 1.63), and a 45% increased risk of EDNOS (HR, 1.45).
The risk of being diagnosed with anorexia (HR, 2.72) and EDNOS (HR, 3.85) was highest in the first three months after hospitalization for an infection. The risk of EDNOS was also highest (HR, 1.60) after hospitalization for a gastrointestinal infection. All three disorders showed a dose response with respect to number of hospitalizations.
Dr. Sarah Altman, Adjunct Professor of Psychiatry and Behavioral Health and Psychology at The Ohio State University Wexner Medical Center in Columbus, commented, "It is important to note that this is a study looking at the association and not the causation of infections and eating disorder diagnosis."
"Most interestingly, they found a higher risk of the development of EDNOS after hospitalization due to a gastrointestinal infection," she told Reuters Health by email. "This is not surprising - an infection that interrupts the normal functioning of the gastrointestinal system will impact appetite and the bacteria of the gut. Mental health professionals who work with individuals...with eating disorders know that difficulty knowing when one is hungry and when one is full is an often-reported struggle for our patients."
"As a clinician, I would keep this study in mind...when I am (assessing) a patient for the first time," she said. "It may be beneficial for clinicians to start asking a simple question such as, 'were you ill or hospitalized for any infections prior to the initial start of your symptoms?' when they complete their initial assessment with a new patient," she said.
Dr. Jennifer MacLeamy, Executive Director at Newport Academy, a treatment center specializing in teen eating disorders, substance abuse and related issues headquartered in Nashville, Tennessee, commented, "While the findings in this study are not identified as causal, ...(they) are alarming in the magnitude of the correlation, and merit additional attention from caregivers and practitioners alike."
"Complicated psychological conditions such as eating disorders rarely have one discrete 'cause,'" she said in an email to Reuters Health. "However, the more we understand the factors that can increase either vulnerability or resilience to developing them, the better equipped we are to treat or even prevent problems."
"Physicians and clinicians are becoming increasingly aware of the links between early psychological trauma and later medical and psychological conditions," she said. "It is my hope that treatment providers will continue to shift the dialogue from 'what's wrong with you' to 'what happened to you' as we all become more trauma-informed."
JAMA Psychiatry 2019.
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