Enhanced Alcohol-Specific Pavlovian-to-Instrumental Transfer in Alcohol Use Disorder

Hao Chen, Sawsan Alachkar, Matthew J. Belanger, Julia Göstl, Clarissa Grundmann, Angela Hentschel, Michaela Reuter, Maximilian Pilhatsch & Michael N. Smolka
Background: The interaction between Pavlovian and instrumental action control is crucial for adaptive behaviour. The interplay between both control modes is thought to be compromised in substance use disorders, as evidenced in cue reactivity studies and studies using Pavlovian-to-instrumental transfer (PIT) tasks. Using a single lever PIT task, our group previously found that alcohol use in young adults, alcohol dependence, and relapse are associated with stronger influence of Pavlovian stimuli on instrumental behaviour (Sommer et al Addict Biol 2020; Chen et al Biol Psychiatry 2023; Chen et al Addict Biol 2023). To directly study the effects of alcohol-associated cues on the preference for alcohol rewards (specific PIT) we developed a novel full transfer task. The aim of the current study was to test whether subjects with alcohol use disorder (AUD) show greater alcohol specific PIT than non-AUD subjects.
Methods: In our novel full transfer task, trial-by-trial gustatory alcohol and juice rewards are delivered during instrumental and Pavlovian conditioning. Piloting in healthy participants has evidenced that both specific and general PIT effects can be elicited with the new task (Belanger et al Neuropsychobiology 2022). For this interims analysis, data from 67 AUD participants (39% female, average age 34, AUD criteria 5, AUDIT score 14.7) and 47 non-AUD participants (47% female, average age 29, AUD criteria 1, AUDIT score 3.0) were assessed. 
Results: Analyses indicate that both the AUD (p<.001, r=.78) and the non-AUD (p<.001, r=.52) group exhibit a substantial specific PIT effect. As hypothesized, the AUD participants exhibit a stronger specific PIT effect in comparison to the controls (p<.001, r=.31). In contrast, the general PIT effect in the full transfer task was only modest (p<.001, ηp2=.10), and did not differ between AUD and non-AUD groups (p=.838, ηp2<.001).
Conclusions: Taken together, results of the novel full transfer task showed group differences between mild to moderate AUD and control participants, indicating that the specific PIT effect seems to be a more sensitive marker for AUD than the general PIT effect. Future research could investigate whether the specific PIT effect is associated with future drinking behaviour and whether this mechanism might be a target for novel interventions.