No medicine comes without side effects. However, a study out today should comfort anyone worried about the long-term consequences of taking methylphenidate, the active ingredient in brand-name drugs for attention deficit hyperactivity disorder such as Ritalin.
Scientists in England investigated the mental health outcomes of people diagnosed with ADHD in Finland. Although people with ADHD are more likely to develop psychotic disorders later in life than people without ADHD, they found no evidence that methylphenidate itself increases this risk. While more research on other ADHD drugs is warranted, the findings address a common fear of taking Ritalin for too long, the researchers say.
“It’s reassuring for doctors, patients and families to decide whether to have stimulant treatment,” study author Ian Kelleher, professor of child and adolescent psychiatry at the University of Edinburgh, told Gizmodo.
Uncertain risk
There are several studies is displayed A small but significant percentage of children diagnosed with ADHD will develop psychotic disorders such as schizophrenia as adults. It is also known that abuse of stimulants can cause similar issues. Because stimulants are a common treatment for ADHD, this raises the concern that therapeutic use of even smaller doses of these drugs may be responsible for the additional risk seen in these children.
According to Kelleher, it would be unethical to conduct the kind of randomized, controlled trials that could definitively examine whether such an association is real (which would, among other things, require some children to be given an ineffective placebo for a long period of time). However, there are still quasi-experimental approaches that can help answer this question.
In this latest study, researchers followed the long-term health status of nearly 700,000 people born in Finland, including 4,000 children and adolescents diagnosed with ADHD. Because prescribing practices for ADHD differ between different hospital regions, the researchers were able to compare rates of psychotic disorders between those who were given methylphenidate for ADHD and those who were not.
“We can use this variation to create a natural experiment to determine whether stimulants are present causes psychosis or not,” said Kelleher, who is an assistant professor in the Faculty of Medicine at University College Dublin.
Overall, about 6% of people with ADHD in the study were later diagnosed with a psychotic disorder by age 30, which is higher than usual. However, long-term use of methylphenidate was not associated with a higher risk. Interestingly, the researchers even found some evidence that methylphenidate may slightly reduce the risk of later psychosis, although this lower risk was only seen in children who started taking the drug before age 13.
Some animal studies have suggested that early exposure to methylphenidate can cause long-term changes in the development of our brain’s dopamine system, helping to “normalize” disorders that can increase the risk of psychosis. However, Kelleher notes that this possible protective effect was small and may have been just a chance finding.
“However, our primary finding of no overall increased risk of psychosis in children and adolescents treated with methylphenidate is robust and reassuring,” he said.
These were the team’s findings has been published Wednesday in JAMA Psychiatry.
Other areas of research are still needed
Methylphenidate is the most commonly prescribed stimulant treatment for ADHD, but it is not the only one. Thus, these results cannot rule out that another major class of ADHD medications, amphetamines such as Adderall, may still increase the risk of psychosis.
It is also unknown whether people who start taking stimulants for ADHD as adults have different risks—a particularly pressing question is the rate of new adult cases in the United States and other countries. rose a lot only in the last few years.
Kelleher and his team hope to explore both of these questions in future similar studies.
