Methamphetamine (METH) is an illicit psychostimulant that is widely abused in the world. Several lines of evidence suggest that chronic METH abuse leads to neurodegenerative changes in the human brain. These include damage to dopamine and serotonin axons, loss of gray matter accompanied by hypertrophy of the white matter and microgliosis in different brain areas. In the present review, we summarize data on the animal models of METH neurotoxicity which include degeneration of monoaminergic terminals and neuronal apoptosis. In addition, we discuss molecular and cellular bases of METH-induced neuropathologies. The accumulated evidence indicates that multiple events, including oxidative stress, excitotoxicity, hyperthermia, neuroinflammatory responses, mitochondrial dysfunction, endoplasmic reticulum stress converge to mediate METH-induced terminal degeneration and neuronal apoptosis. When taken together, these findings suggest that pharmacological strategies geared towards the prevention and treatment of the deleterious effects of this drug will need to attack the various pathways that form the substrates of METH toxicity. Keywords methamphetamine; neurotoxicity; dopamine; oxidative stress; serotonin; cell death
Epidemiology of Methamphetamine AbuseAbuse of the illegal psychostimulant, methamphetamine (METH), has become an international public health problem with an estimated 15-16 million users worldwide, a total which exceeds the number of people who abuse heroin and cocaine and makes METH the second most widely abused drug after cannabis (United Nations Office on Drugs and Crime, 2007). The inexpensive production of METH, its low cost, and long duration of action have made it a very desirable commodity. Indeed, METH is a popular drug of abuse in Australia (Australian Institure for Health and Welfare, 2005), Canada (Canadian Centre on Substance Abuse, 2005), Czech Republic and Slovakia (European Monitoring Center for Drugs and Drug Addiction, 2007). During the last decade, Southeast Asia and East Asia have become global hubs for METH production and trafficking, with a coincident epidemic of psychostimulant abuse in these regions (United Nations Office on Drugs and Crime, 2007). It is estimated that over half of the world's METH consumers reside in Southeast Asia and East Asia (United Nations Office on Drugs and Crime, 2007). Japan, in particular, has experienced several epidemics of crystal METH abuse, including a peak in 1999-2000. Since the late 1990s, METH use rose to epidemic Correspondence: Jean Lud Cadet M.D., Chief, Molecular Neuropsychiatry Reasearch Branch, Intramural Research Program, NIDA/NIH/ DHHS, 251 Bayview Boulevard, Baltimore, MD 21224, USA, jcadet@intra.nida.nih.gov, Tel: 443-740-2656, Fax: 443-740-2856. Publisher's Disclaimer: This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before...