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ADHD medication has no damaging long-term effect on the brain

06 December 2016

​ADHD medication has no damaging long-term effect on the way young children’s brains develop. In addition, the behaviour of children who take medication for ADHD develops in the same way as that of children with ADHD who do not take medication. These are the results of research carried out by brain researcher Lizanne Schweren of the University Medical Center Groningen. She will be awarded a PhD by the University of Groningen on 14 December for research into the long-term effect of medication on children with ADHD.

ADHD (attention deficit/hyperactivity disorder) is a common developmental disorder, characterized by concentration problems, impulsive behaviour and hyperactivity. ADHD is often diagnosed during childhood and the problems continue into adolescence and adulthood. The exact cause of ADHD has not yet been discovered. It is probably the result of several different factors, including genetic and environmental factors, each of which affects the development and progress of the disorder. ADHD is commonly linked to changes in the dopamine system. Studies also show subtle abnormalities in certain areas of the brain or brain systems of people with ADHD.

Long-term effects of ADHD medication

The past few decades have seen a rise in the use of ADHD medication, particularly stimulants such as Ritalin. A lot of people are concerned about exposing children to medication before the long-term effect on the development of the brain has been ascertained. In her thesis, Lizanne Schweren describes the findings from research into the long-term effects of ADHD medication on the developing brain. She studied the brain structure and function of around 1,000 children, adolescents and young adults, more than 400 of whom had ADHD. Most of them had used medication for ADHD at some in their life, but the level of usage differed greatly. Some had only used it once or twice, while others had been on daily medication for many years.

No damaging effect on the brain

Schweren’s research revealed no signs of damaging long-term effects of ADHD medication on the development of the brain. The use of medication does not alter the thickness of the cerebral cortex, which appeared slightly thinner in a part of the brain of children and adolescents with ADHD. In addition, she found no link with the volume of the frontal cortex, which is often smaller in children with ADHD. So unlike previous research, Schweren’s research provides no proof that the long-term use of medication normalizes the development of the brain. She only found a subtle effect of medication in a very small sub-group of children. This effect appears to be positive rather than negative.

No difference in behaviour

Schweren also shows that ADHD medication has no long-term effect (either positive or negative) on children’s mental and social-emotional performance. The behaviour of children with ADHD who take medication develops in the same way as that of children with ADHD who do not.

Relevance to doctors and parents

Schweren’s research shows a remarkable absence of long-term behavioural effects. According to Schweren, it is important that doctors explain to young people and their parents that although ADHD medication will probably reduce the symptoms of ADHD, it does not give better long-term results. They would do well to realize that their symptoms will lessen as they reach adulthood, whether they use medication or not. In other words, taking medication will not speed up or enhance the natural progress of their condition, but neither will it slow it down or impede it.

​Curriculum vitae

Lizanne Schweren (Geldrop, 1986) studied psychology at Radboud University Nijmegen and neuroscience at VU University Amsterdam. She conducted her research, which was partly funded by the Netherlands Organisation for Health Research and Development (ZonMW), at the BCN-BRAIN research institute of the UMCG in Groningen.
The title of her thesis is: Stimulants and the developing brain. She is currently working as a post-doc researcher at the University of Cambridge.