Ritalin Improves Ability to Learn
Ritalin (methylphenidate), a drug prescribed for millions of children who have attention deficit hyperactivity disorder (ADHD), appears to improve the ability to learn by enhancing the speed of learning. Currently, Ritalin is prescribed to help inhibit impulsive behavior, which in turn can improve a child’s ability to focus on tasks.
The new finding is the result of research by investigators at the University of California, San Francisco (UCSF). It is significant because it lets scientists know that Ritalin impacts and improves behavior through two specific types of neurotransmitter receptors rather than just one. Neurotransmitters are chemicals that act as messengers to allow neurons to communicate with each other.
Previously experts knew that Ritalin enhanced the activity of the neurotransmitter dopamine receptor known as D2, which controls the ability to stay focused on a task. The new research shows that another dopamine receptor called D1, which is involved in the ability to learn and learning efficiency, is also affected by Ritalin. Apparently the drug produces these benefits by strengthening the ability of the neurons to communicate with each other at their meeting points, called synapses.
These new findings may allow researchers to develop more efficient drugs to treat ADHD and to improve the ability to focus and learn more efficiently, according to Antonello Bonci, MD, principal investigator at the Ernest Gallo Clinic and Research Center and professor of neurology at UCSF.
The UCSF research team evaluated the ability of rats to learn how to get a reward when they received a visual and audio signal. Two groups of rats were studied: one group received Ritalin, the other did not, and both groups were subjected to the same tests. The rats that received Ritalin learned much better than the untreated rats.
What was especially exciting was that when the researchers blocked the dopamine D1 receptors with drugs, Ritalin did not enhance learning. When the D2 receptors were blocked, Ritalin did not improve the ability to focus. Thus the scientists were able to establish the unique role of each of the dopamine receptors and their relationship with Ritalin in cognitive performance.
Yet one more finding of the study was that the improvements in learning and focus seen in the rats were achieved using doses of Ritalin comparable to those given to children.
Ritalin has been prescribed for millions of children and adults for several decades. Since 1990, there has been an estimated 300 percent increase in use of this drug for therapeutic purposes. Methylphenidate is also available under several other brand names, including Concerta and Metadate, and is the most prescribed stimulant drug used to treat ADHD.
ADHD affects an estimated 4.5 million children ages 4 to 17, according to the Centers for Disease Control and Prevention. Approximately 4.1 million adults ages 18 to 44 also have the disorder, according to the National Institute of Mental Health.
Ritalin is prescribed so often to so many children, and the fact that it can cause so many changes in the brain makes it difficult for scientists to determine which changes impact the ability to learn. The results of this UCSF study indicate that Ritalin can improve the ability to learn via its association with another dopamine receptor, and they enhance researchers understanding of this drug’s activity in the brain
Centers for Disease Control and Prevention
National Institute of Mental Health
University of California San Francisco news release Mar. 8, 2010