Cocaine craving is associated with electrophysiological brain responses to cocaine-related stimuli
Several studies show that substance dependence disorders are characterized by an enhanced processing of substance-related stimuli. The present study was designed to examine the association between craving levels and selective processing of drug cues in cocaine-dependent patients using event-related brain potentials (ERPs). In abstinent cocaine-dependent patients and a healthy control group, we studied the late positive potential (LPP) amplitudes elicited by neutral and cocaine-related stimuli. The results show that cocaine-dependent patients have an enhanced electrophysiological response in the late LPP time window to cocaine-related stimuli as compared to controls, suggesting an enhanced processing of these stimuli. Most importantly, a robust association was observed between cocaine craving and LPP amplitude. High craving levels were associated with larger LPP amplitudes at central electrode sites in the right hemisphere. These findings are in line with theories linking motivational aspects and appetitive stimulus processing. Furthermore, it is demonstrated that ERPs are a useful index to assess motivational properties of stimuli in cocaine-dependent patients. These findings suggest that electrophysiological measures may have clinical relevance in substance use disorders.