While the results are reassuring, it is still important to monitor weight changes and blood pressure.
An Australian ADHD expert has welcomed a study showing methylphenidate is physically and mentally safe for children and adolescents when used for at least two years.
Professor Michael Kohn, a director of ADHD Australia, and head of department for AYA Medicine at Westmead Hospital, said that while the results were reassuring, patients still needed to be monitored for effects on weight, growth and blood pressure.
“Those impacts around appetite, weight and growth can occur,” he told The Medical Republic.
“I think this study is reassuring that when we look at the population, when we look at the group of people that are treated with stimulant medication, there’s no group effect that we can statistically determine.”
Methylphenidate is one of the most frequently prescribed medication for the treatment of ADHD in children and adolescents in Australia and many other countries around the world.
Although many randomised controlled trials support short-term efficacy, tolerability, and safety, data on long-term safety and tolerability was scarce, said the authors of the prospective, longitudinal, controlled study, published in The Lancet Psychiatry.
The study investigated the safety of methylphenidate over a two-year period in relation to growth and development, psychiatric health, neurological health, and cardiovascular function in children and adolescents.
It was conducted as part of the ADDUCE research program in 27 European child and adolescent mental health centres in the UK, Germany, Switzerland, Italy, and Hungary. A total of 1410 participants aged 6–17 years were recruited into three cohorts – a methylphenidate group, a no-methylphenidate group and a control group. More than three quarters of the subjects were male.
The study found that apart from a reduction in weight velocity at the six-month assessment, methylphenidate was not associated with effects on growth and development, or psychiatric or neurological symptoms at up to two years.
However long-term methylphenidate treatment was associated with moderate increases in systolic and diastolic blood pressure and pulse rate.
“Our results suggest that long-term treatment with methylphenidate for two years is safe,” the authors wrote.
“There was no evidence to support the hypothesis that methylphenidate treatment leads to reductions in growth. Methylphenidate-related pulse and blood pressure changes, although relatively small, require regular monitoring.”
Professor Kohn told TMR that while growth and weight loss were not a major issue for most patients, there was a sub-group of people with ADHD who experienced a profound loss of appetite when taking prescribed stimulant medication. These patients could experience weight loss, he said.
He said these patients might be better suited to non-stimulant medications for ADHD, of which a number have become available in recent years on the PBS.
It was also important to note that some patients might have other conditions that impact eating and appetite – particularly in children.
“If it’s ADHD in the context of a more broad, neurodiverse presentation, then there might be sensitivity issues around food or fussy and restricted eating – so there may be other contexts in which the ADHD is occurring that compound the effect of appetite suppression,” Professor Kohn said.
