Children and adolescents with attention-deficit/hyperactivity disorder (ADHD) who receive long-term methylphenidate treatment face increased risks for overweight or obesity and slightly reduced height in adulthood, highlighting the need for regular monitoring of growth and body composition to inform personalized management strategies.

Clinicians should weigh these potential effects against the benefits of symptom control and incorporate counseling on nutrition, sleep, and physical activity to mitigate risks.

Children and adolescents with ADHD appear to face a higher risk of being overweight in adulthood and may be slightly shorter than average, particularly if they receive long-term treatment with methylphenidate.

That is the conclusion of a retrospective cohort study from South Korea, presented by a team led by Jihun Song, PhD, from the Department of Biomedical Informatics, Korea University College of Medicine, Seoul, South Korea, and colleagues, published in JAMA Network Open.

“The findings of this study suggest that children with ADHD, especially those receiving methylphenidate therapy, may face greater risks of obesity and modest height reduction, highlighting the importance of continuous growth monitoring,” the authors wrote.

Methylphenidate Exposure

Researchers analyzed data from 12866 children aged 6-11 years, 72.5% of whom were boys, and 21984 adolescents 12-19 years of age, including 66.6% boys, all with a diagnosis of ADHD. The investigators focused primarily on children, given their greater growth potential than adolescents.

Overall, 6816 children (53%) and 10658 adolescents (48.5%) received methylphenidate, with wide variations in treatment duration and dosage. BMI and height were recorded at least once between 20 and 25 years of age.

Overweight was defined as a BMI of 25 or higher for young men and 23 or higher for young women. Short stature was defined as a mean adult height below 174.4 cm for men and below 161.8 cm for women.

An equal number of girls and boys without ADHD served as control groups. Each participant with ADHD was matched 1:1 to a control group without ADHD by age, sex, and income level. All data were obtained from the National Health Insurance Service, which covers more than 97% of the South Korean population.

Increased Risk for Overweight

In young adulthood, the mean BMI was 24.3 in individuals diagnosed with ADHD in childhood and 23.0 in those without ADHD. The prevalence of overweight or obesity was 35.0% of participants without ADHD, 44.9% of those with ADHD, and 46.5% of those treated with methylphenidate.

Mean adult height did not differ significantly between children with and without ADHD, measuring 167.8 cm and 167.9 cm.

These differences were more pronounced among the participants who received methylphenidate. Those with ADHD treated with methylphenidate had a 1.6-fold higher risk for overweight or obesity in adulthood and a 1.08-fold higher risk for short stature than those without ADHD. Similar but weaker associations were observed when adolescent data were included in the analysis.

Among boys, the effects were more evident for BMI, whereas among girls, the effects were more apparent for height. The mean BMI of male participants treated with methylphenidate in childhood was 25.4. The treatment duration also mattered. Boys who had methylphenidate for longer than 1 year had the highest BMI in adulthood, with a mean value of 26.

Among female participants, mean adult height was 161.6 cm in the group without ADHD, 161.4 cm in those with ADHD, 161.2 cm in those treated with methylphenidate, and 161.0 cm in those who had received methylphenidate for longer than 1 year.

“Although the observed height difference was clinically small in both sexes and age groups, the findings suggest that long-term methylphenidate exposure may be associated with growth and body composition, highlighting the need for regular monitoring of growth,” the authors concluded.

Possible Mechanisms

The authors also proposed potential mechanisms underlying these findings. “As methylphenidate is well known to suppress short-term appetite, skipping meals and overeating due to appetite rebound may contribute to being overweight,” wrote the authors.

They also noted that growth hormone is primarily secreted during deep sleep. Chronic sleep disruption, which is more frequently observed during methylphenidate therapy, may interfere with hormone secretion and slow growth, thereby limiting the final adult height.

Despite these findings, researchers do not argue against methylphenidate therapy. The medication effectively alleviated the core symptoms of ADHD. Clinicians should, however, remain aware of the potential effects on growth.

The authors recommend regular monitoring of weight and height, along with counseling on nutrition, sleep, and physical activity, to mitigate the potential adverse effects of methylphenidate treatment.

“Future research should focus on identifying modifiable risk factors, optimizing treatment strategies, and developing comprehensive guidelines for monitoring growth and metabolic health in populations with ADHD,” the researchers concluded.

This story was translated from Medscape’s German edition.