Long-Term Methylphenidate Use Safe for Pediatric ADHD Patients

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There was very little evidence of an effect growth or increased risk of psychiatric or neurological adverse events in the methylphenidate group compared with the no-methylphenidate group.

New data indicates methylphenidate is safe for pediatric patients with attention deficit/hyperactivity disorder (ADHD).1

A team, led by Kenneth K C Man, PhD, Research Department of Practice and Policy, School of Pharmacy, University College London, identified the safety of methylphenidate over a 2 year period in relation to growth and development, psychiatric health, neurological health, and cardiovascular function in pediatric patients with ADHD.


Currently, methylphenidate is the most commonly prescribed treatment for pediatric patients with ADHD in many countries. However, while there have been randomized controlled trials that show short-term efficacy, tolerability, and safety of methylphenidate in this patient population, there is a need for long-term safety and tolerability data.

In the naturalistic, longitudinal, controlled study, the investigators examined 1410 patients aged 6-17 years with ADHD between February 1, 2012 and January 31, 2016.

The study was part of the ADDUCE research program, which takes place in 27 European child and adolescent mental health centers in the UK, Germany, Switzerland, Italy, and Hungary.

The Patients

The patients were either medication naïve who intended to start methylphenidate treatment (n = 756), medication-naïve who did not intend to start any ADHD medication (n = 391), or a control group without ADHD (n = 263). The patient population was 76.3% (n = 1070) male with an average age of 9.28 years.

Each participant was diagnosed with ADHD in accordance with the DSM-IV criteria. In the control group, participants scored less than 1.5 on average on the Swanson, Nolan, and Pelham IV rating ascale ADHD items and whose hyperactivity score on the parent-rated Strengths and Difficulties Questionnaire was within the normal range (<6).

The exclusion criteria included those who had taken any ADHD medications. However, they remained eligible if they had previously taken or were currently taking other psychotropic drugs.

The investigators sought primary outcomes of height velocity, defined as height velocity standard deviation score, estimated from at least 2 consecutive height measurements, and normalized with reference to the mean and standard deviation of a population of the same age and sex.

The results show methylphenidate and no-methylphenidate groups often differed in ADHD symptom severity and other characteristics.

However, after the team controlled for the effects of variables using propensity scores, they found very little evidence of an effect growth (24 months height velocity SD score difference, –0·07; 95% CI, –0·18 to 0·04; P = 0.20) or increased risk of psychiatric or neurological adverse events in the methylphenidate group compared with the no-methylphenidate group.

The results also show that the pulse rate and systolic and diastolic blood pressure were higher in the methylphenidate group compared to the no-methylphenidate group after 24 months of treatment. There were no serious adverse events identified.

“Our results suggest that long-term treatment with methylphenidate for 2 years is safe. There was no evidence to support the hypothesis that methylphenidate treatment leads to reductions in growth,” the authors wrote. “Methylphenidate-related pulse and blood pressure changes, although relatively small, require regular monitoring.”


Man, K. K., Häge, A., Banaschewski, T., Inglis, S. K., Buitelaar, J., Carucci, S., Danckaerts, M., Dittmann, R. W., Falissard, B., Garas, P., Hollis, C., Konrad, K., Kovshoff, H., Liddle, E., McCarthy, S., Neubert, A., Nagy, P., Rosenthal, E., Sonuga-Barke, E. J., … Uebel-von Sandersleben, H. (2023). Long-term safety of methylphenidate in children and adolescents with ADHD: 2-year outcomes of the attention deficit hyperactivity disorder drugs use chronic effects (adduce) study. The Lancet Psychiatry.