Methamphetamine Users in Sustained Abstinence: A Proton Magnetic Resonance Spectroscopy Study

BACKGROUND Abnormal patterns of metabolite levels have been detected by magnetic resonance spectroscopy in frontostriatal regions of individuals meeting DSM-IV criteria for methamphetamine dependence, but less is known about the effects of drug abstinence on metabolite levels. OBJECTIVE To assess the effects of long-term methamphetamine use and drug abstinence on brain metabolite levels. DESIGN To assess regional specific metabolite levels using magnetic resonance spectroscopy imaging techniques in 2 groups of currently abstinent methamphetamine users: methamphetamine users who recently initiated abstinence and methamphetamine users who had initiated abstinence more than 1 year prior to study. SETTING Participants were recruited from outpatient substance abuse treatment centers. PARTICIPANTS Eight methamphetamine users with sustained abstinence (1 year to 5 years) and 16 recently abstinent methamphetamine users (1 month to 6 months) were compared with 13 healthy, non–substance-using controls. MAIN OUTCOME MEASURES Magnetic resonance spectroscopy measures of N-acetylaspartate–creatine and phosphocreatine (NAA/Cr), choline–creatine and phosphocreatine (Cho/Cr), and choline–N-acetylaspartate (Cho/NAA) ratios were obtained in the anterior cingulate cortex as well as in the primary visual cortex, which served as a control region. RESULTS The absolute values of Cr did not differ between controls and methamphetamine users. Methamphetamine users had abnormally low NAA/Cr levels within the anterior cingulate cortex, regardless of the time spent abstinent (F2,34 = 12.61; P