Does alcohol cue inhibitory control training survive a context shift?

Pilot testing of an adaptive, individualized inhibitory control training for binge drinking: first evidence on feasibility, acceptance, and efficacy

Background

Deficits in inhibitory control seem to promote habit behavior and therefore play an important role in the development and maintenance of addictive diseases. Although several training approaches have been suggested, there is a considerable lack of knowledge about the best way to improve inhibitory control. Based on a literature review regarding shortcomings of existing trainings, an individualized, adaptive inhibitory control training was developed. We aimed to assess feasibility and acceptance of this training and to provide preliminary results on its efficacy regarding inhibitory control and binge drinking.

Methods

Sixty-one individuals (30 female) with binge drinking behavior were randomly allocated to either an experimental group receiving three sessions of the inhibitory control training or a waitlist control group receiving no training. Before and after the training, the participants performed a Go/NoGo task to assess inhibitory control (commission errors and false reaction time), completed a questionnaire on drinking-related self-control, and reported drinking behavior.

Results

Although the training was feasible and accepted by participants, it did not affect self-control over drinking, inhibitory control or drinking behavior. The relationship between session number and false reaction time was linear for alcohol stimuli, but squared for neutral stimuli.

Conclusion

Although our findings have to be interpreted in the light of some shortcomings, they demonstrate that further research is needed to enhance our understanding of how to improve inhibitory control and which factors might moderate this process.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00426-022-01725-4.

Transcranial direct current stimulation combined with alcohol cue inhibitory control training reduces the risk of early alcohol relapse: A randomized placebo-controlled clinical trial

BACKGROUND

Approximately half of all people with alcohol use disorder (AUD) relapse into alcohol reuse in the next few weeks after a withdrawal treatment. Brain stimulation and cognitive training represent recent forms of complementary interventions in the context of AUD.

OBJECTIVE

To evaluate the clinical efficacy of five sessions of 2 mA bilateral transcranial direct current stimulation (tDCS) for 20 min over the dorsolateral prefrontal cortex (DLPFC) (left cathodal/right anodal) combined with alcohol cue inhibitory control training (ICT) as part of rehabilitation. The secondary outcomes were executive functioning (e.g. response inhibition) and craving intensity, two mechanisms strongly related to abstinence.

METHODS

A randomized clinical trial with patients (n = 125) with severe AUD at a withdrawal treatment unit. Each patient was randomly assigned to one of four conditions, in a 2 [verum vs. sham tDCS] x 2 [alcohol cue vs. neutral ICT] factorial design. The main outcome of treatment was the abstinence rate after two weeks or more (up to one year).

RESULTS

Verum tDCS improved the abstinence rate at the 2-week follow-up compared to the sham condition, independently of the training condition (79.7% [95% CI = 69.8-89.6] vs. 60.7% [95% CI = 48.3-73.1]; p = .02). A priori contrasts analyses revealed higher abstinence rates for the verum tDCS associated with alcohol cue ICT (86.1% [31/36; 95% CI = 74.6-97.6]) than for the other three conditions (64% [57/89; 95% CI = 54-74]). These positive clinical effects on abstinence did not persist beyond two weeks after the intervention. Neither the reduction of craving nor the improvement in executive control resulted specifically from prefrontal-tDCS and ICT.

CONCLUSIONS

AUD patients who received tDCS applied to DLPFC showed a significantly higher abstinence rate during the weeks following rehabilitation. When combined with alcohol specific ICT, brain stimulation may provide better clinical outcomes.

TRIAL REGISTRATION

ClinicalTrials.gov number NCT03447054 https://clinicaltrials.gov/ct2/show/NCT03447054.

Elevated ad libitum alcohol consumption following continuous theta burst stimulation to the left-dorsolateral prefrontal cortex is partially mediated by changes in craving

Previous research indicates that following alcohol intoxication, activity in prefrontal cortices is reduced, linking to changes in associated cognitive processes, such as inhibitory control, attentional bias (AB), and craving. While these changes have been implicated in alcohol consumption behaviour, it has yet to be fully illuminated how these frontal regions and cognitive processes interact to govern alcohol consumption behaviour. The current preregistered study applied continuous theta burst transcranial magnetic stimulation (cTBS) to examine directly these relationships while removing the wider pharmacological effects of alcohol. A mixed design was implemented, with cTBS stimulation to right and left dorsolateral prefrontal cortex (DLPFC), the medial orbital frontal cortex (mOFC) and Vertex, with measures of inhibitory control, AB, and craving taken both pre- and post-stimulation. Ad libitum consumption was measured using a bogus taste task. Results suggest that rDLPFC stimulation impaired inhibitory control but did not significantly increase ad libitum consumption. However, lDLPFC stimulation heightened craving and increased consumption, with findings indicating that changes in craving partially mediated the relationship between cTBS stimulation of prefrontal regions and ad libitum consumption. Medial OFC stimulation and AB findings were inconclusive. Overall, results implicate the left DLPFC in the regulation of craving, which appears to be a prepotent cognitive mechanism by which alcohol consumption is driven and maintained.