Childhood Ritalin Use May Have Long-Term Effects on the Brain
A new study finds that levels of the neurotransmitter GABA may be lower in the brains of adults who started taking methylphenidate as children.
September 8, 2017
Stimulant medications used to treat ADHD, like Ritalin and Adderall, have been extensively studied and found to be safe — in the short-term. For the most part, however, their long-term effects on the human brain are not well understood.
A small new study may shed some light on how persistent stimulant use changes the brain. It finds that adults who started a medication regimen during childhood have different levels of certain neurotransmitters — and a different reaction to subsequent doses of Ritalin — than do those patients who began treatment as adults.
The study, published in June in NeuroImage: Clinical, looked at 44 male patients with ADHD, all between the ages of 23 and 40. The subjects were divided into three groups: those who started taking Ritalin (the brand name of methylphenidate) before the age of 16; those who first took Ritalin after the age of 23; and those who had never taken stimulants to treat their ADHD symptoms. All participants underwent baseline brain scans; some subjects from all three groups were later administered a dose of Ritalin and scanned again.
The initial scans revealed that the brains of subjects who began taking Ritalin before the age of 16 (the “early treatment” group) had lower levels of GABA — a neurotransmitter linked to inhibition control and often implicated in the neurological makeup of ADHD — than did those who started stimulants later or never took them all. After Ritalin was administered, however, and the patients re-scanned, only the early treatment group saw any increase in GABA levels.
The implications of these varying GABA levels are not quite clear as of yet, but the researchers note that use of methylphenidate early in life — while the brain is in the process of developing — appears to have concrete and lasting neurological effects. Methylphenidate use also appears to affect patients’ brains in different ways in the short term, depending on when treatment was first initiated — as seen in the increased levels of GABA shortly after the drug was administered.
“The results from our study suggest that stimulants have different effects when acting on the developing or the mature brain,” the authors write. “Future studies are therefore warranted to assess the underlying mechanisms, as well as the consequences of these lower GABA+ levels on cognitive and behavioral problems in ADHD.”