Event-related potentials indicate motivational relevance of cocaine cues in abstinent cocaine addicts (2004)

RATIONALE:

Motivational drive and its underlying affect-related states are the core mechanisms that precede the seeking and taking of drugs in substance dependence.

OBJECTIVE:

The present study aimed to investigate the motivational relevance of cocaine cues and whether or not an appetitive emotional system is involved employing event-related potential (ERP) measurements.

METHODS:

Cocaine-addicted subjects and healthy controls were exposed to neutral and cocaine-related pictures whilst ERPs were recorded simultaneously over frontal, parietal and midline sites.

RESULTS:

Patients exhibited ERP amplitude discrepancies between neutral and cocaine-related pictures for N300, late slow positive wave (LSPW) and sustained slow positive wave (SSPW), whilst this effect was absent in control subjects. Differences in neutral and cocaine cue-evoked ERP waves were also found at left frontal sites for LSPW and SSPW in the patient group only. No group-specific cue-evoked ERP amplitudes were observed at parietal and midline sites.

CONCLUSION:

The findings confirm the assumption that cocaine cues induce motivational relevance in cocaine-dependent individuals. It is possible that exposure to cocaine cues triggers an appetitive emotional system since left frontal sites are assumed to be involved in processing positive emotional-laden stimuli. The present study provides evidence that the sensitivity of ERP correlates for cocaine cues may be an indicator of motivational and emotional processes in drug-dependent individuals.