Methylphenidate and D2 Receptors: An Overview
Methylphenidate is a commonly prescribed medication approved for the treatment of
ADHD and
narcolepsy. It is also a commonly abused drug
(see Ritalin Abuse). Methylphenidate is sold in various forms under the following brand names:
Research suggests that both the effectiveness of methylphenidate for ADHD and its potential for abuse are related to its effect on dopamine in the brain.
Dopamine and D2 Receptors
Dopamine is one of several monoamine neurotransmitters in the brain. There are at least five types of dopamine receptors: D1, D2, D3, D4, and D5. Dopamine can have different effects when it is bound to different receptor types. D2 receptors have been linked to the reinforcing aspects of drug use. "Reinforcement" is the scientific word for the feelings (or changes in the brain) that lead people to repeat certain actions (such as abusing a drug). Animal studies have shown that drugs like
morphine and amphetamine do not have reinforcing effects in mice that do not have D2 receptors.