Top of page
Health

Cycles of Reward: New Insight into ADHD Treatment

girl with ADHD playing

Attention-Deficit Hyperactivity Disorder (ADHD) is a widespread condition with complex underlying causes. A stimulant drug called methylphenidate is a common ADHD treatment that impacts the brain’s levels of dopamine, a neurotransmitter involved in systems of reward; however, methylphenidate has a potential for abuse, and its therapeutic effects are poorly understood.

To explore methylphenidate’s varied interactions with dopamine systems in the brain, researchers at the Okinawa Institute of Science and Technology Graduate University (OIST) in collaboration with scientists at the University of Otago and the University of Auckland in New Zealand, investigated the actions of the drug in rats. Using dopamine cell recordings, electrochemical monitoring and computer modeling, they discovered a type of feedback loop that modulates dopamine levels in the rats’ brains in response to the drug. This regulatory process may shed light on methylphenidate’s therapeutic properties in ADHD. The researchers’ findings are published in Progress in Neurobiology.

“We know quite a bit about how methylphenidate works at the molecular level, but not how it affects greater neural systems. It’s still a mystery how this drug improves symptoms of ADHD,” said Professor Jeff Wickens of OIST’s Neurobiology Research Unit. “This mystery leads us to explore how different parts of the brain interact to produce therapeutic effects.”

To carry out their research, the international team administered methylphenidate at a concentration of 5.0 mg/kg to a group of adult male rats, while a control group received no drugs. After surgically implanting electrodes in the rats’ brains, the researchers used an electrochemical technique called voltammetry to monitor real-time changes in cellular dopamine concentration in brain regions involved in ADHD. The researchers also took measurements in live brain slices of rats’ midbrains and forebrains.

To help understand the data, the scientists at OIST, including technician Kavinda Liyanagama, designed a computer program to model the effects of methylphenidate on dopamine systems.

You might also like

woman and grandson with using a walker during rehabilitation woman and grandson with using a walker during rehabilitation

Stroke survivors with depression face higher risk of death and disability

People who experience depression following a stroke may face a…

Scott Flanagan and his family wearing pirate eye patches Scott Flanagan and his family wearing pirate eye patches

Therapist shares personal stroke journey to raise awareness

For years, Scott Flanagan has cared for patients recovering from…

Medicine Medicine

Medicaid cuts tied to higher death rates, study finds

A new analysis provides evidence that reductions in access to…

man holding his painful knee man holding his painful knee

Study reveals hundreds of genetic connections to osteoarthritis

Over 900 genetic links to osteoarthritis, including 500 that have…