Limbic activation during cue-induced cocaine craving.
OBJECTIVE: Since signals for cocaine induce limbic brain activation in animals and cocaine craving in humans, the objective of this study was to test whether limbic activation occurs during cue-induced craving in humans. METHOD: Using positron emission tomography, the researchers measured relative regional cerebral blood flow (CBF) in limbic and comparison brain regions of 14 detoxified male cocaine users and six cocaine-naive comparison subjects during exposure to both non-drug-related and cocaine-related videos and during resting baseline conditions. RESULTS: During the cocaine video, the cocaine users experienced craving and showed a pattern of increases in limbic (amygdala and anterior cingulate) CBF and decreases in basal ganglia CBF relative to their responses to the non-drug video. This pattern did not occur in the cocaine-naive comparison subjects, and the two groups did not differ in their responses in the comparison regions (i.e., the dorsolateral prefrontal cortex, cerebellum, thalamus, and visual cortex). CONCLUSIONS: These findings indicate that limbic activation is one component of cue-induced cocaine craving. Limbic activation may be similarly involved in appetitive craving for other drugs and for natural rewards.