Alcohol approach bias is associated with both behavioral and neural Pavlovian-to-instrumental transfer effects in alcohol-dependent patients

Even after qualified detoxification, alcohol-dependent (AD) patients may relapse to drinking alcohol despite their decision to abstain. Two mechanisms may play important roles: first, the impact of environmental cues on instrumental behavior (i.e., Pavlovian-to-instrumental transfer (PIT) effect), which was found to be stronger in prospectively relapsing AD patients compared to abstaining patients. Second, an automatic approach bias towards alcohol stimuli was observed in AD patients, and interventions targeting this bias reduced the relapse risk in some studies. Previous findings suggest a potential behavioral and neurobiological overlap between these two mechanisms. In the current study, we examined the association between the alcohol approach bias and both the behavioral and neural non-drug-related PIT effects in AD patients after detoxification. N = 100 AD patients (17 females) performed a PIT task and an alcohol approach/avoidance task (aAAT). Patients were followed up for 6 months. A stronger alcohol approach bias was associated with both a more pronounced behavioral PIT effect and a stronger PIT-related neural activity in the right nucleus accumbens (NAcc). Moreover, the association between the alcohol approach bias and the behavioral PIT increased with the severity of alcohol dependence and trait impulsivity, and was stronger in patients who relapsed during follow-up in the exploratory analysis. These findings indicate partial behavioral and neurobiological overlap between the alcohol approach bias and the PIT effect assessed with our tasks. The association was stronger in patients with more severe alcohol dependence.