Cerebral phosphorus metabolite and transverse relaxation time abnormalities in heroin-dependent subjects at onset of methadone maintenance treatment

Cerebral bioenergetic and phospholipid abnormalities have been reported in hero in-dependent subjects. The goal of the present study was to characterize the neurochemical profile of subjects voluntarily enrolled in a methadone maintenance (MM) treatment program to overcome their heroin addiction. Participants included 43 hero in-dependent subjects during their first month of MM and 15 age-matched healthy individuals. Phosphorus magnetic resonance spectroscopy (P-31 MRS) and transverse relaxation times (T2-RT), which can reflect steady state cerebral perfusion and metabolism, were acquired at 1.5 T from an axial slice prescribed through the orbitofrontal and occipital cortices, including basal ganglia and frontal cortex. MM subjects exhibited reduced phosphocreatine (PCr) levels (-15.3%), elevated phosphodiesters (+ 12.9%, PDE) and significantly longer T2-RT (+) 2.1%) compared with healthy comparison subjects. When MM subjects were stratified into subgroups based on treatment duration, we found a treatment duration effect on metabolite values but not T2-RT; reduced PCr was observed only after 8+ days of MM, and phosphomonoesters (PME) were elevated in the 15-28 day MM group. Taken together, these cross-sectional data suggest that the first month of MM treatment may be associated with altered cerebral bioenergetics and phospholipid metabolite levels. (C) 2004 Elsevier Ireland Ltd. All rights reserved.