The Reduced Response Inhibition To Drug-related Cues In Heroin Abstainers

A typical feature of drug addiction is impulse drug seeking and using. For heroin addiction, previous research focused on two aspects: On the one hand, some studies found that there was more attentional bias for drug-related cues in heroin addicts; on the other hand, other studies found that impaired response inhibition existed in heroin addicts. These two aspects may cause individual impulse drug-seeking, using and relapse. However, few studies have explored the correlations between cognitive inhibition and attentional bias in detoxified heroin addicts. Therefore, the aim of this research was to investigate the influencing cognitive mechanism of drug-related attentional bias on response inhibition by using ERP technology with high temporal resolution in heroin abstainers.16 male heroin abstainers during abstinence and 15 healthy no-drug users who matched in terms of age were recruited in current study. The adjusted version of the two-choice Oddball task was used, including two conditions: A. the neutral condition,the neutral "chair" picture served as the standard stimuli, neutral pictures served as deviant stimuli; B. drug-related condition, the neutral "chair" picture served as the standard stimuli, heroin-related pictures served as deviant stimuli. Wherein, the probabilities of standard stimuli and deviant stimuli were 80% and 20%, participants were asked to press different keys on the keyboard in response to standard stimuli and deviant stimuli as rapidly and accurately as possible.The results showed below,(1) In the behavioral level, compared to the standard stimuli, there were longer reaction time and higher error rate for the deviant stimuli in all subjects.(2) In the EEG level, compared to the standard stimuli, the deviant stimuli evoked significantly larger N2 and P3 amplitude.(3) The analysis for differences wave which was the result of deviant stimuli minus standard stimuli showed that there was no significant difference in amplitude of N2 and P3 between two groups under neutral conditions.(4) Under heroin-related condition, compared to no-drug users, there was smaller negative bias of the difference wave of N2 in heroin abstainers. And compared to the neutral condition, heroin abstainers had smaller negative bias of the difference wave of N2 under heroin-related condition.The results may suggest that,(1) Heroin addicts have normal response inhibitionafter long-term abstinence, in other word, their impaired response inhibition can get restored potentially through abstinence.(2) But the effect of drug-related cues on their response inhibition exists after long-term abstinence, the drug-cues reduce their earlier conflict detection and monitoring related to response inhibition. The reduced ability to suppress response to drug-related cues is a potential risk factor for relapse after withdrawal in heroin addicts, which will be the target of future intervention.