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Researchers find inadequate evidence of methylphenidate efficacy for ADHD

A recent Cochrane Review indicated methylphenidate may improve teacher-reported attention-deficit/hyperactivity disorder symptoms, teacher-reported general behavior and parent-reported quality of life among youth with the disorder, however, evidence was low-quality and therefore could not confirm findings.

To assess benefits and harms of methylphenidate for children and adolescents with attention-deficit/hyperactivity disorder (ADHD), Ole Jakob Storebø, PhD, of University of Southern Denmark, Odense, Denmark, and colleagues analyzed 185 randomized trials that compared methylphenidate with placebo or no intervention among youth with ADHD. Analysis included 38 parallel-group trials with 5,111 randomized participants and 147 cross-over trials with 7,134 randomized participants. Study participants had a mean age of 9.7 years.

Duration of methylphenidate treatment ranged from 1 to 425 days, with a mean duration of 75 days.

Researchers found that methylphenidate may improve teacher-rated ADHD symptoms, with a mean difference of –9.6 points on the ADHD Rating Scale. However, evidence was very low quality.

There was no evidence that methylphenidate was associated with increased serious adverse events.

Among youth prescribed methylphenidate, 526 per 1,000 experienced nonserious adverse events, compared with 408 per 1,000 among controls, indicating a 29% increase in overall risk of any nonserious adverse events.

The most common nonserious adverse events were sleep problems and decreased appetite. Youth receiving methylphenidate had a 60% increased risk for trouble sleeping or sleep problems and 266% increased risk for decreased appetite, compared with controls.

Change in Child Health Questionnaire scores reported in a meta-analysis of three trials corresponded with a mean difference of 8 points, suggesting methylphenidate may improve parent-reported quality of life, though evidence was very low quality, according to researchers.

“Methylphenidate may improve ADHD symptoms, general behavior and quality of life in children and adolescents aged 18 years and younger with ADHD. We rated the evidence to be of very low quality and, as a result, we cannot be certain about the magnitude of the effects from the meta-analyses. The evidence is limited by serious risk of bias in the included trials, under-reporting of relevant outcome data, and a high level of statistical variation between the results of the trials. There is also very low quality evidence that methylphenidate causes numerous adverse events,” Storebø and colleagues wrote. “To assess whether any benefits are provided by methylphenidate, large, randomized, nocebo tablet (‘active placebo’) controlled trials are needed to compare the drug with a nocebo tablet, if deblinding can be excluded.” – by Amanda Oldt

Disclosure: The researchers report no relevant financial disclosures.