Effects of Methamphetamine Abuse on Neurotransmission and Cognition.
Methamphetamine is a synthetically derived substance with a high potential for abuse and dependence (Nordahl et al., 2003; Volkow et al., 2001). The abuse of methamphetamine has grown rapidly throughout the United States since the early 1990's. The widespread availability of methamphetamine is largely due to the fact that it can be manufactured using chemicals found at a local hardware or drugstore. According to the U.S. Drug Enforcement Agency (DEA), "among the controlled substances manufactured underground in the United States, methamphetamine is the most prevalent, and it is one of the commonly abused controlled substances that can be made in the home" (Nordahl et al., 2003, p. 318). The national increase in methamphetamine abuse led to the development of the Comprehensive Methamphetamine Control Act of 1996 and the Methamphetamine and Club Drug Anti-Proliferation Act of 2000 (Nordahl et al., 2003). These acts of national legislation were designed to increase the awareness of methamphetamine use and the dangers associated with its abuse. .
The national rise in methamphetamine abuse also led to a public demand for the discovery and understanding of the neurotoxic affects on brain functioning. Many researchers have focused on discovering regions of the brain that are affected by chronic methamphetamine abuse (Volkow et al., 2001), while others have focused on the content of those regions. Within the various regions of the brain are the dopamine, serotonin, and glutamate neurotransmitter systems that are responsible for causing the different behavioral and emotional reactions to a drug. The abuse of methamphetamine has been associated with profound damage to these neurotransmitters, specifically the dopamine transport system (Brown et al., 2000; Nordahl et al., 2003; Salo et al., 2002; Volkow et al, 2001; & Zickler, 2002). The neurotoxic effects of methamphetamine abuse on the dopamine transport system are highly correlated with the acute and long-term impairments to neurocognitive functioning (Kalechstein et al.