Meta-Analysis Finds Association Between Obesity and ADHD in Adults, Children

Adults and children with attention-deficit/hyperactivity disorder (ADHD) are significantly more likely than those without the condition to be obese, according to a meta-analysis of studies appearing August 28 in AJP in Advance.

SUNY Upstate Medical University

“Obesity is a serious public health problem,” affecting 17 percent of children and 35 percent of adults in the United States,” said the study’s senior author, Stephen Faraone, Ph.D., a distinguished professor in the departments of Psychiatry and Neuroscience and Physiology at SUNY Upstate Medical University, in an interview with Psychiatric News. “Attention-deficit/hyperactivity disorder [ADHD] is another frequent and impairing condition,” affecting 5 percent of school-age children. These children have a 65 percent chance of ADHD symptoms following them into adulthood.

According to Faraone and colleagues, independent studies evaluating whether an association between obesity and ADHD exists have drawn conflicting conclusions. If a significant association is found between ADHD and obesity, the researchers noted, individuals affected by both would represent a sizable portion of the general population in need of care—which is highly relevant from a clinical and public health standpoint.

To examine the relationship between obesity and ADHD, the international team of researchers searched through a broad range of databases and unpublished material to identify population-based studies and clinical studies consisting of individuals with ADHD who were then compared with non-ADHD controls.

Of the 42 studies (which included 728,136 people) selected for inclusion, the researchers found that obesity was significantly associated with an ADHD diagnosis in both adults and children. The estimated prevalence of obesity was increased by about 70 percent in adults with ADHD compared with adults without ADHD and by about 40 percent in children with ADHD compared with children without ADHD. The researchers also noted that ADHD individuals taking medication for the disorder were not at any additional risk for obesity than those with untreated ADHD.

Though reasons for the link between ADHD and obesity are unknown, Faraone speculates that it may be due to ADHD symptoms such as impulsivity that could lead to impulsive eating and poor self-regulation of eating behaviors, “so the effect could be behavioral,” he explained. “It is also possible that ADHD and obesity share underlying causes; for example, genes or environmental risk factors might cause both disorders.”

Whatever the underlying causes for the association between the two disorders may be, Faraone told Psychiatric News that realizing that ADHD may serve as a potential risk factor for obesity, “health care professionals may be able to alert parents to this concern, monitor the patient, and perhaps intervene early to prevent obesity by modifying lifestyle factors.”

The researchers noted that “assessing the risk for obesity should be part of the assessment and management of ADHD.” They concluded that clinicians should also screen for ADHD in individuals who are referred for obesity, especially those with a previous history of unsuccessful weight-loss attempts.

The study was funded by Aargon Healthcare Italy. ■