Methylphenidate and D2 Receptors
The binding of dopamine to D2 receptors is caused by methylphenidate. D2 receptors have been linked to the reinforcing aspects of drug use, so the potential for drug abuse is increased with use of methylphenidate. Since dopamine changes in the brain appear to be an important factor in ADHD, and methylphenidate increases dopamine (and binding to D2 receptors) in certain parts of the brain, it is effective for ADHD treatment.
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:
- Metadate ER®
- Metadate CD®
- Methylin ER®
- Ritalin LA®
- Ritalin SR®.
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 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.