Increased P3 amplitudes induced by alcohol-related pictures in patients with alcohol dependence

Alcohol craving, a key element in alcohol dependence, is recognized as being a kind of motivational or emotional state. It is meaningful in research and clinical practice involving alcohol dependence to explore ways of measuring alcohol craving. The aim of this study was to measure the P3 event-related potentials induced by alcohol-related pictures in patients with alcohol dependence; these potentials are considered to constitute a neuronal correlate of alcohol craving.

On the basis of our previous study, six alcohol-related pictures and six neutral pictures were chosen as the visual stimuli. Each set of stimuli consisted of alcohol-related or neutral pictures as the target stimuli and same-sized checkerboards as the nontarget stimuli. The stimuli were presented by using the oddball paradigm for 300 msec, with an interstimulus interval of 1000 msec, in 12 controls and 16 abstinent patients with alcohol dependence. Each electroencephalography session consisted of three blocks: a practice block, a neutral block, and an alcohol-craving block.

The amplitudes of P3 elicited by the alcohol-related pictures were significantly larger than those elicited by the neutral pictures in the patients with alcohol dependence, whereas there was no significant difference according to the stimuli in the P3 amplitudes of controls. Repeated-measures ANOVA on the amplitudes of P3 revealed that there was a significant interaction effect of block by subject group.

These results suggest that event-related potentials can be used as a neuronal correlate of alcohol craving in alcohol-dependent patients. Future investigations will be needed to assess the frequency of relapse in the patients included in this study, to elucidate the meaning of the observed results with regard to the therapeutic outcomes.