Assessing drug cue-induced brain response in heroin dependents treated by methadone maintenance and protracted abstinence measures

Methadone maintenance treatment (MMT) and protracted abstinence (PA) are common methods of therapy in heroin addiction as both suppress the craving for drug use. However, the difference in patterns of brain function between two groups is unknown. Functional magnetic resonance imaging (fMRI) based drug cue-reactivity task is a good tool to understand the change of brain function during a certain period of treatment. Twenty-three heroin-dependent patients during PA, 18 heroin-dependent patients during MMT and 20 healthy control (HC) individuals were included to conduct the heroin cue-reactivity task during fMRI. The MMT and PA patients’ subjective craving for heroin was evaluated. Differences among the three groups were analyzed with respect to heroin cue induced brain responses. Compared with HC group, MMT and PA groups commonly demonstrated significantly higher brain responses during exposure of heroin-related cues in the bilateral caudate, right thalamus, left hippocampus, parahippocampus, midbrain, left superior parietal lobule, right middle occipital gyrus, left posterior cingulate cortex and right cerebellum. However, compared with PA group, MMT group demonstrated significantly greater brain response mainly in right caudate, hippocampus, midbrain left fusiform, right inferior parietal lobule, left posterior cingulate cortex, cerebellum and postcentral gyrus. No difference in cue induced craving between MMT and PA groups was found. The findings suggest that MMT group demonstrated more enhanced drug cue induced brain responses than PA group, indicating that, these two treatments have different effect on patterns of brain response to heroin related cues in heroin-dependent individuals.