A Clinical Trial with Combined Transcranial Direct Current Stimulation and Attentional Bias Modification in Alcohol‐Dependent Patients

Abstract

BackgroundModifying attentional processes with attentional bias modification (ABM) might be a relevant add‐on to treatment in addiction. This study investigated whether influencing cortical plasticity with transcranial direct current stimulation (tDCS) could increase training effects. tDCS could also help alcohol‐dependent patients to overcome craving and reduce relapse, independent of training. These approaches were combined to investigate effects in the treatment of alcoholism.MethodsNinety‐eight patients (analytical sample = 83) were randomly assigned to 4 groups in a 2‐by‐2 factorial design. Patients received 4 sessions of ABM (control or real training) combined with 2 mA tDCS (active: 20 minutes or sham: 30 seconds) over the left dorsolateral prefrontal cortex. Alcohol bias and craving were assessed, and treatment outcome was measured as relapse after 1 year.ResultsAttentional bias scores indicated that during the training only the group with active tDCS and real ABM displayed an overall avoidance bias (p < 0.05). From pre‐ to postassessment, there were no main or interaction effects of tDCS and ABM on the bias scores, craving, or relapse (p > 0.2). However, effects on relapse after active tDCS were in the expected direction.ConclusionsThere was no evidence of a beneficial effect of tDCS or ABM or the combination. Whether the absence of effect was due to issues with the outcome measurements (e.g., lack of craving, high dropout, and unreliable measurements) or aspects of the intervention should be further investigated.

Alcohol-Specific Computerized Interventions to Alter Cognitive Biases: A Systematic Review of Effects on Experimental Tasks, Drinking Behavior, and Neuronal Activation

“…Research investigating the effects of VPT-AtBM has reported changes in VPT-AtB in the expected direction in young adult drinkers (38), heavy social drinkers (35), heavy drinkers (HD) (10,32,40), and AUD (31). Another study in AUD showed a trend (27), while two studies in AUD (29,30), and one in binge drinkers (36) found no effects. It is also noteworthy that in Rinck et al (27), neither baseline bias nor bias change did mediate drinking changes.…”

“…Generally, motivation to change is assumed to be higher in populations with more problematic drinking patterns. When considering clinical trials on AtBM in AUD, however, two of four studies reported that AtBM increases the time to first drink at 3-month follow-up (31) or reduces relapse rates at 1-year follow up (27), while two other studies failed to report such effects at 4-week (29) or 1-year follow-up (30). Interestingly, those studies, which reported evidence for a bias change (27,31) were also those reporting drinking effects, while the studies, in which the bias could not be changed did not find any effects on drinking behavior (29,30).…”

Non-invasive Brain Stimulation for Alcohol Use Disorders: State of the Art and Future Directions

“…No significant effects for craving were found. In another study, the same group [56] (n = 83) did not find significant effects of tDCS on craving or 1-year relapse rates.…”

“…In considering context during stimulation, an interesting pattern emerges. Studies that involved the presentation of alcohol-related cues in various tasks during stimulation [51,[54][55][56]59] provide weak or no evidence of a positive effect of tDCS on alcohol-related outcomes. This is especially of interest in connection with a tDCS study done for methamphetamine use which found that tDCS reduced craving whereas stimulation was administered at rest (i.e., as monotherapy), but observed increased craving when administered during a cue-induced craving task [66].…”

Better Together? Coupling Pharmacotherapies and Cognitive Interventions With Non-invasive Brain Stimulation for the Treatment of Addictive Disorders

“…Preliminary evidence in the field of AD have also been reported. Specifically, in a recent trial in patients with alcohol use disorders (AUD), 4 sessions of attentional bias training (control or real) were combined with either sham or active tDCS over the DLPFC, using a 2-by-2 doubleblind factorial design (den Uyl et al, 2018). Combined active tDCS and real training did not produce any significant effect on alcohol craving and relapse, and on attentional biases toward alcohol.…”