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.


METHODS
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.


METHODS
Participants were recruited from outpatient substance abuse treatment centers.


METHODS
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.


METHODS
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 (F(2,34) = 12.61; P<.001). No NAA/Cr group differences were observed in the primary visual cortex (F(2,33) = 0.29; P = .75). The Cho/NAA values for the anterior cingulate cortex were abnormally high in the methamphetamine users who recently initiated abstinence but followed a normal pattern in the methamphetamine users who had initiated abstinence more than 1 year prior to study (F(2,34) = 7.31; P = .002).


CONCLUSIONS
The relative choline normalization across periods of abstinence suggests that following cessation of methamphetamine use, adaptive changes occur, which might contribute to some degree of normalization of neuronal structure and function in the anterior cingulum. More research is needed to elucidate the mechanisms underlying these adaptive changes.
Nordahl
Thomas E
TE
Department of Psychiatry and Behavioral Sciences, University of California Davis Medical Center, 4701 X Street, Sacramento, CA 95817, USA. tenordahl@ucdavis.edu
Salo
Ruth
R
Natsuaki
Yutaka
Y
Galloway
Gantt P
GP
Waters
Christy
C
Moore
Charles D
CD
Kile
Shawn
S
Buonocore
Michael H
MH
D000328:Adult; D000553:Ambulatory Care; D019969:Amphetamine-Related Disorders / Q000453:epidemiology / Q000378:metabolism*; D001224:Aspartic Acid / Q000031:analogs & derivatives* / Q000378:metabolism; D001921:Brain / Q000378:metabolism*; D002794:Choline / Q000378:metabolism; D003401:Creatine / Q000378:metabolism; D004298:Dopamine / Q000378:metabolism; D005260:Female; D006179:Gyrus Cinguli / Q000378:metabolism; D006801:Humans; D009682:Magnetic Resonance Spectroscopy; D008297:Male; D008694:Methamphetamine / Q000378:metabolism*; D010725:Phosphocreatine / Q000378:metabolism; D016320:Substance Abuse Treatment Centers; D013375:Substance Withdrawal Syndrome / Q000378:metabolism; D014018:Tissue Distribution; D014793:Visual Cortex / Q000378:metabolism
D010725:Phosphocreatine; D001224:Aspartic Acid; D008694:Methamphetamine; C000179:N-acetylaspartate; D003401:Creatine; D002794:Choline; D004298:Dopamine