Craving correlates with mesolimbic responses to heroin-related cues in short-term abstinence from heroin: an event-related fMRI study.

Craving is an important factor in relapse to drug abuse, and cue-induced craving is an especially powerful form of this construct. Neuroimaging methods have been utilized to study drug cue-induced craving and neural correlates in the human brain. However, very few studies have focused on characterizing craving and the neural responses to heroin-related cues in short-term abstinent heroin-dependent patients. Twenty-four heroin-dependent subjects and 20 demographically matched drug-naïve subjects participated in this study. An event-related cue-reactivity paradigm was employed, while changes in blood oxygen level-dependent (BOLD) signals were acquired by functional magnetic resonance imaging (fMRI). The heroin-dependent group reported significantly increased craving following exposure to heroin-related cues. Direct comparison between the two groups showed that brain activation to heroin-related minus neutral cues was significantly greater for the heroin-dependent group in the bilateral nucleus accumbens (NAc), caudate, putamen, amygdala, hippocampus/parahippocampus, midcingulate cortex, dorsolateral prefrontal cortex (DLPFC), orbitofrontal cortex (OFC), medial frontal gyrus (MeFG), midbrain, thalamus, left anterior cingulate cortex (ACC), posterior cingulate cortex (PCC), and subcallosal gyrus. Changes in craving in the heroin-dependent group correlated positively with brain activation in the bilateral NAc, caudate, right putamen, and left ACC. The abstinence duration correlated positively with brain activation in the left caudate and right parahippocampal gyrus. In conclusion, the cue-reactivity paradigm significantly activated neural responses in the mesolimbic dopamine (DA) system and prefrontal cortex (PFC) and induced increased craving in short-term abstinent heroin-dependent patients. We suggest that these response patterns characterize the high vulnerability of relapse in short-term abstinent heroin-dependent subjects.