Methamphetamine increases the amount of the neurotransmitter dopamine, leading to high levels of that chemical in the brain. Dopamine is involved in reward, motivation, the experience of pleasure, and motor function. Methamphetamine's ability to release dopamine rapidly in reward regions of the brain produces the euphoric rush or flash that many users experience. Repeated methamphetamine use can easily lead to addiction a chronic, relapsing disease characterized by compulsive drug seeking and use.
Methamphetamine can be prescribed by a doctor to treat ADHD and other conditions, although it is rarely used medically, and only at doses much lower than those typically abused. It is classified as a Schedule II drug, meaning it has high potential for abuse and is available only through a prescription that cannot be refilled. People who use methamphetamine long-term may experience anxiety, confusion, insomnia, and mood disturbances and display violent behavior. They may also show symptoms of psychosis, such as paranoia, visual and auditory hallucinations, and delusions (for example, the sensation of insects crawling under the skin).
Related to:
Desoxyn, ADHD, Narcolepsy, Amphetamine, Dextroamphetamine (Adderall)