Two Years of Methylphenidate Use Likely Does Not Affect Growth in Children With ADHD

Two years of treatment with methylphenidate for attention-deficit/hyperactivity disorder (ADHD) did not affect growth outcomes among children. These results from a study were published in The Lancet Psychiatry.

The Attention Deficit Hyperactivity Disorder Drugs Use Chronic Effects (ADDUCE) study was a prospective, pharmacovigilance, multicenter study conducted between 2012 and 2016 at 27 mental health centers in the United Kingdom and in other countries in Europe. Children and adolescents with ADHD who were treatment-naïve and about to start methylphenidate (n=756) or had no intention to start methylphenidate (n=391) and a group of healthy controls (n=263) were followed for 2 years. The outcomes of interest in this study were height, weight, cardiovascular health, and psychiatric outcomes.

The methylphenidate, no treatment, and control groups comprised children with mean ages 9.22, 8.74, and 10.25 years (P <.0001); 82.2%, 84.1%, and 45.2% were boys (P <.0001); 92.1%, 95.4%, and 92.4% were White; and they had BMIs of 18.4, 17.9, and 18.4 kg/m², respectively.

Methylphenidate appeared to slow weight velocity at 6 months compared with ADHD nonusers (P <.0001), however, no differences in weight were observed thereafter, nor were there any significant group differences in height or BMI throughout the study.

At 12 months, methylphenidate use associated with significantly elevated pulse rate, systolic blood pressure, and diastolic blood pressure (all P <.0001) compared with nonusers with ADHD. Between baseline at 24 months systolic blood pressure increased from 108 to 113 mmHg (P <.0001) among methylphenidate users and from 104 to 108 mmHg (P <.0001) among nonusers with ADHD while remaining unchanged among controls (mean, 109 vs 111 mmHg; P =.08), respectively. In addition, significant increases in diastolic blood pressure (mean, 65 vs 67 mmHg; P =.02) and pulse (mean, 80 vs 83 bpm) were observed among methylphenidate users between baseline and 24 months, respectively.

Methylphenidate use also significantly decreased the Swanson Nolan and Pelham IV rating scale (SNAP-IV) summary score (P <.0001), SNAP hyperactive summary score (P <.0001), SNAP inattention summary score (P <.0001), child-reported Mood and Feelings Questionnaire (MFQ) mood score (P =.0003), and parent-reported MFQ mood score (P =.02) compared with nonusers with ADHD.

Among the ADHD cohorts, the methylphenidate users and nonusers did not differ with any psychosis, alcohol use, marijuana use, smoking, tics, or suicidality outcomes at 6, 12, or 24 months, with the exception that methylphenidate users were more likely to present with a tic at 12 months (odds ratio, 4.70; 95% CI, 1.07-20.77; P =.04).

There were no serious adverse events that occurred during the study.

The major limitation of this study was the high loss to follow-up, in which only 53.5% of participants attended the 24-month follow-up visit.

Study authors concluded, “[T]he results of this study suggest that the safety profile of long-term treatment with methylphenidate for 2 years is acceptable. The data do not support the hypothesis that long-term methylphenidate treatment is associated with impairments in growth.”

Disclosure: Some study authors declared affiliations with biotech, pharmaceutical, and/or device companies. Please see the original reference for a full list of authors’ disclosures.