Weight Variance Linked to Medication in Youth With ADHD

Children and adolescents with attention deficit/hyperactivity disorder (ADHD) who are not taking medications have a slightly higher likelihood of being overweight; however, those taking ADHD medications have a higher likelihood of being underweight, according to a population study published in the July Pediatrics.

The authors, Molly Waring, M.A., and Kate Lapane, Ph.D., of the Department of Community Health at Brown Medical School, analyzed data from 62,887 individuals aged 5 to 17 who had participated in the 2003-2004 National Survey of Children's Health, a national survey sponsored by the Maternal and Child Health Bureau and the National Center for Health Statistics in the Department of Health and Human Services. Information about each child's or teenager's weight, height, diagnosis of ADHD by a health professional, and whether the child or teenager was taking medication prescribed for ADHD, was collected through telephone interview with a parent or guardian in the household.

Underweight was defined in this study as having a body mass index (BMI) at or below the 5th percentile for the same age group and gender on the Centers for Disease Control and Prevention growth chart. Having a BMI at or above the 95th percentile was considered overweight.

Children and adolescents with ADHD and not taking medications had an odds ratio of 1.5 for being overweight, compared with those without ADHD. In contrast, those with ADHD and currently taking medications had an odds ratio of 1.6 for being underweight. These risk ratios were calculated after adjusting for age, gender, race/ethnicity, socioeconomic status, and comorbid depression and anxiety.

In this population sample, 8.8 percent were reported to have had a diagnosis of ADHD or attention deficit disorder. About 72 percent of these children and adolescents were currently taking medications.

The findings in this cross-sectional study echo other studies that looked at the effects of ADHD medications on children's growth and development.

Long-term results from the Multimodal Treatment Study of Children With ADHD (MTA) study, published in the August 2007 Journal of the American Academy of Child and Adolescent Psychiatry, have shown that children taking ADHD medications for three years have lower growth rates in both height and weight (Psychiatric News, August 17, 2007). A subgroup analysis by James Swanson, Ph.D., and colleagues found that children with ADHD were on average of larger size than norms before receiving stimulant treatment, but their growth slowed after they were put on medication. On average, children who took stimulants for three years were 2.0 cm shorter in height and 2.7 kg less in weight than unmedicated children.

The causes for these variances in the growth and development of children with ADHD remain unknown. Waring and Lapane suggested that the impulsivity and decreased behavior regulation in untreated ADHD children may contribute to overeating and poor nutritional habits, while the appetite suppression among stimulants' side effects may be a reason for underweight in treated children. The study was limited by its cross-sectional design and parent/guardian-reported data, the authors acknowledged. Nevertheless, they recommended that pediatric care providers pay more attention to monitoring the weight of ADHD patients.

An abstract of “Overweight in Children and Adolescents in Relation to Attention-Deficit/Hyperactivity Disorder: Results From a National Sample” is posted at<pediatrics.aappublications.org/cgi/content/short/122/1/e1>. An abstract of “Effects of Stimulant Medication on Growth Rates Across 3 Years in the MTA Follow-up” is posted at<www.jaacap.com/pt/re/jaacap/abstract.00004583-200708000-00012.htm>.▪