ADHD/ADD is a disorder that is characterized by increased motor activity, impulsiveness, distractibility, restlessness and inattention. Much of what is actually going on in the brain of an ADHD/ADD patient is still uncertain. This uncertainty has made the task of treating this condition much more difficult. The predominantly held belief is that the condition is caused by a dysfunction in the neurotransmitters: dopamine (DA) and norepinephrine (NE).

Dopamine (picture on right) is the neurotransmitter that is believed to be heavily involved in the mediation of reward responses to behavior. For example, when a drug is ingested into the body, that has pleasurable effects, that drug causes DA ro be released in order to create that pleasurable sensation. There are many things that can trigger DA (pleasure) release: foods, activities, drugs (both legal and illegal), and even social interaction can all cause DA release. Quite simply, DA release in the brain makes things and events feel good.

Norepinephrine (NE) is a neurotransmitter that is very similar in chemical composition to DA, in fact, they are both synthesized, in the brain, from the same starting material . NE (picture on left) is the neurotransmitter that is believed to be associated with an individual's ability to focus on a task and to remain focused on the task. Simply put, NE is the vigilance neurotransmitter.

Many experiments and tests have shown that the brains of individual's with ADD and ADHD have subnormal levels of DA and NE. It is believed that these neurotransmitter deficits are the causes of ADD/ADHD individuals' difficulty in focusing on particular tasks and being motivated to complete tasks. The picture to the right shows a normal brain on the left and an ADD/ADHD brain on the right.

Drugs that are used to treat ADD/ADHD act to increase the levels of the neurotransmitters dopamine and norepinephrine in the brain. The most commonly prescribed drug to treat ADD/ADHD is methylphenidate (MP) which is more commonly known as Ritalin.

How does MP work?

What other drugs are used to treat ADD/ADHD?