Scientists say children treated for ADHD with Ritalin may suffer damage to the brain’s impulse control in adulthood.
Researchers found early exposure to methylphenidate, or Ritalin, lowers levels of Gamma-aminobutyric acid (GABA) in the pre-frontal cortex of adult brains.
Not convinced by the research: psychiatrist Professor Peter Hill says the findings could relate to the severity of the ADHD rather than treatment
The researchers, from the University of Amsterdam, say GABA is an amino acid with links to impulse control.
But the scientists found a different result in those exposed to methylphenidate for the first time in adulthood. These patients did not show the same reduced levels of GABA.
Long-lasting alterations
The researchers say their findings show methylphenidate may induce long-lasting alterations to the brain’s impulse control when doctors start the treatment at a young age.
In their paper the researchers say the drug could induce “later changes in impulsivity, that in turn, could make patients more vulnerable for risk-taking behavior and/or later drug (ab)use.”
Comorbid symptoms
In 2014, Israeli researcher Yael Leitner reported studies in the US and Europe. These show that between 37 per cent and 85 per cent of children with autism have “comorbid symptoms of ADHD”.
Harley Street psychiatrist professor Peter Hill is a member of UKAP, the UK ADHD partnership.
He warned that while the study was “well conducted”, those treated in childhood may have had more severe symptoms.
In an email Professor Hill wrote that “ the findings could relate to severity of the ADHD rather than treatment”.
Methylphenidate is the main treatment for people with ADHD. And prescription rates are rising.
Ritalin use has rocketed
Use of Ritalin and similar products has rocketed over the last decade or so. There were 922,200 prescriptions in the UK in 2014. By contrast there were just 359,100 in 2004.
The growth has fuelled concerns about doctors inappropriately prescribing stimulants.
Guidelines suggest their use should be a last resort.
The Dutch study, titled ‘Age-dependent, lasting effects of methylphenidate on the GABAergic system of ADHD patients’, was published in NeuroImage: Clinical.
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Published: 14 July 2017
