Decreased cerebral blood flow of the right anterior cingulate cortex in long-term and short-term abstinent methamphetamine users.

BACKGROUND The aim of the current study was to explore changes of relative regional cerebral blood flow (rCBF) in short-term and long-term abstinent methamphetamine (MA) users. METHODS Relative rCBF in 40 abstinent MA users and 23 healthy comparison subjects was compared by the technetium-99m-hexamethyl-propylene amine oxime ((99m)Tc-HMPAO) single photon emission computed tomography (SPECT). Relative rCBF in areas that were found to differ significantly was also compared in groups of MA users with short-term (<6 months) and long-term (>or=6 months) abstinence. RESULTS MA users showed decreased relative rCBF in the right anterior cingulate cortex (Brodmann area 32) relative to healthy comparison subjects. Long-term abstinent MA users had significantly greater rCBF than short-term abstinent MA users. CONCLUSIONS We report that abstinent MA users have decreased rCBF in the anterior cingulate cortex with smaller relative decreases in subjects with prolonged abstinence.