The National Institute on Drug Abuse (NIDA) has long recognized the danger of methamphetamine abuse, and has actively supported research on this and related drugs. Understanding methamphetamine's effects on the brain and behavior is critical to developing both prevention and treatment strategies.
Methamphetamine is a long-acting and very potent stimulant drug. It can be snorted, swallowed, injected, or smoked, and it is frequently taken in combination with other drugs. Like other drugs of abuse, methamphetamine produces a sense of euphoria by increasing the release of dopamine in the brain's reward centers.
When dopamine is liberated in such high concentrations, it can damage dopamine cells. Indeed, several studies in laboratory animals have corroborated this. In humans, imaging studies have shown that methamphetamine abusers show abnormalities in dopamine function resulting in impairments in movement and cognitive function that are similar, though of a lesser severity, to those seen in patients with Parkinson's disease. The good news is that unlike Parkinson's disease, where the damage to the brain cannot be reversed, with protracted abstinence from methamphetamine, there is some return of function. This further highlights the importance of instituting treatment for methamphetamine abusers to maximize their chances of a successful recovery.
There are other dangerous effects of methamphetamine. The large increases in dopamine produced by methamphetamine can trigger psychosis that in some instances persists months after drug use has stopped. Also, because methamphetamine affects the contraction of blood vessels it can result in heart attacks and strokes in relatively young patients.
In addition to its effects on the brain, methamphetamine use is inextricably linked to risky sexual behaviors, thus increasing the risk for transmission of infectious diseases, including HIV. The recent case of a methamphetamine abuser with a particularly virulent strain of HIV is a sobering reminder of this connection. Those who inject the drug risk contracting HIV through the sharing of contaminated equipment, and methamphetamine's physiological effects may also favor HIV transmission and progression. Preliminary studies suggest that HIV-positive methamphetamine abusers who are on antiretroviral therapy are at greater risk of progressing to AIDS than non-users. Furthermore, interactions between methamphetamine and HIV itself may lead to greater neuronal damage and functional impairment.
Methamphetamine addiction can be treated successfully using currently available behavioral treatments and NIDA is also investing in the development of new medications for methamphetamine addiction. NIDA also is pursuing the development of an immunization strategy based on monoclonal antibodies for the treatment of methamphetamine overdose.
In addition to funding research in this important area, NIDA has a great deal of information on its website about the health effects of methamphetamine abuse that we hope you will find helpful.
Sincerely,
Nora D. Volkow, M.D.
Director
Read my Senate Testimony on Methamphetamine from April 21, 2005. (Archives)