Clinical Textbook of Addictive Disorders 3rd ed - R. Frances, S. Miller, A. Mack (Guilford, 2005) WW

208 III. SUBSTANCES OF ABUSEnin, and their precursor enzymes tyrosine hydroxylase, and tryptophan hydroxylase,are depleted, which in turn affects levels of the major metabolites ofthese transmitters, their receptors, and their reuptake transporters. Methamphetaminealso affects serotonergic, noradrenergic, and glutamatergic systemsthrough interactions with dopamine transporters, monoamine transporters, andN-methyl-D-aspartate (NMDA) receptors. Nitric oxide may have a role inmethamphetamine-induced behavioral sensitization and neurotoxicity.Chronic methamphetamine abuse can lead to psychotic behavior (particularlyparanoia), visual and auditory hallucinations, and violent behavior.Chronic methamphetamine users also demonstrate deficits in attention, verbalmemory, abstract reasoning, task shifting, and spatial abilities (Simon etal., 2000). Animal studies have demonstrated that chronic administration ofmethamphetamine decreases striatal concentrations of dopamine and dopaminemetabolites in several regions of the brain (Nordahl, Salo, & Leamon,2003).Other than symptomatic treatment of drug-induced sequelae, there are nospecific pharmacological treatments for methamphetamine addiction (Lukas,1997). Continued progress in understanding the neurobiological basis for methamphetamineaddiction, as well as medication development initiatives aimed atcocaine and other drugs, may benefit methamphetamine pharmacotherapy inthe future. Nonpharmacological therapies for methamphetamine addiction aresimilar to those for other chemical dependencies but need to take into accountmethamphetamine’s longer duration of action, withdrawal period, and potentiallylonger recovery phase. In addition, methamphetamine users may experienceparanoia, psychotic symptoms, and protracted depression and anhedonia,making them more difficult to treat than the standard drug treatment population.Regarding nonpharmacological treatment, methamphetamine usersand cocaine users respond similarly to manualized behavioral and cognitivebehavioraltreatment strategies (Shoptaw, Rawson, McCann, & Obert, 1994).In addition, new behavioral treatments under development show promise. TheMatrix Program, a multisite, Center for Substance Abuse Treatment (CSAT)–funded drug treatment program, demonstrated significantly reduced methamphetamineuse from pretreatment levels in a follow-up sample 2–5 yearsposttreatment (Rawson et al., 2002). However, continuing high rates of dropoutand relapse in this population indicate a need for further treatment researchfor this difficult population.CONCLUSIONOver the past 15 years, much has changed with regard to the use and our understandingof both amphetamines and cocaine. Most notably, cocaine depend-