Introduction

Alcoholism is a progressive neurocognitive disorder, where premorbid vulnerability factors interact with neuroadaptations resulting from excessive drinking. Lack of cognitive control over impulses can be a risk factor for and a consequence of addition, with increased evidence indicating that the latter maybe strong when excessive substance use starts in adolescence. Recent research emphasizes the importance of the malleable adolescent brain in the early development of addiction (note: clinical patients typically adult, with large age-range). Some of the later stages of addiction usually occur later in life. But some of the neurocognitive abnormalities in addiction may reverse after prolonged abstinence or targeted training.

Biomedical research emphasizes that addiction should be seen as a chronic brain disease, but this shouldn’t lead to the conclusion that nothing can be done about it. In addition to traditional treatments, a novel set of training-paradigms have been developed, known as Cognitive Bias Modification (CBM). These have generated positive first results in the treatment of problem drinking in a community sample, and alcoholism in patients. These interventions aim to directly change the automatic/implicit cognitive motivational processes involved in addiction, of which patients may not always be aware and are difficult to control/change by more traditional means. This study focuses on re-training one of these implicit processes: automatically triggered action tendency to approach alcohol.

A first clinical study on the effects of CBM tested effects of four sessions of A-AAT (alcohol approach-avoidance task) training in alcohol-dependent patients in an inpatient setting. Results showed patients’ alcohol-approach bias to change to alcohol-avoidance bias – generalizing to untrained pictures in the same task. Patients in the training group showed 13% less relapse in one year after treatment compared to the control group.

Little is known about predictors of successful training. Various studies found implicit cognitive processes to be a better predictor of alcohol use in people with relatively weak executive control (EC) capacities. Recent study found that EC moderates the relation between alcohol-approach tendencies and drinking behaviour in high-risk adolescents and may also moderate training effects (stronger effects in those with weak EC). One can conclude that approach-bias re-training may work well for patients with weak EC and so we should use a classic Stroop colour-word interference task as a potential moderator. Deviant brain activation during a Stroop task has been associated with risk for addiction in adolescents with family history of alcoholism, and children with ADHD when they’re off medication.

This study has two main objectives: 1) to test if the effect of adding computerized approach-bias re-training to cognitive behavioural treatment increases abstinence in alcoholic inpatients, and whether the effect on treatment outcome would be mediated by the amount of change in approach-bias. 2) to investigate whether success of training can be predicted by patients’ level of EC and/or background variables.

Methods

Participants

Alcohol-dependent patients administered to a three-months inpatient treatment. We included every patient with a primary alcohol dependency diagnoses. Exclusion criteria were neuro-cognitive problems, strong withdrawal symptoms, history of schizophrenia, and visual or hand-motoric handicaps. None of the patients received anti-craving medications. The final analytical sample consisted of 475 patients.

Assessment and outcome measures

Patients were diagnosed at intake using the computerized version of the CIDI (Composite International Diagnostic Interview) and a diagnostic interview. Both the CIDI and interview ere the basis for the final expert ratings on diagnoses made by clinical psychologists.

Experimental Task

Alcohol-AAT (Approach-Avoidance Task)

The alcohol AAT measures the automatic approach tendency toward alcohol. Participants asked to react to the format of pictures using a joystick, ignoring the pictures’ contents. Two categories of pictures – 20 alcoholic beverages, and 20 soft drinks. Pushing a picture away would decrease its size, and pulling a picture closer would increase its size.

Alcohol- AAT (Approach-Avoidance Task)-Training Version

For CBM, A-AAT was used. Training effect was achieved by presenting alcohol pictures in the push-away format and soft-drink pictures in the pull-closer format.

Colour Stroop (EC)

Variety of the Colour Stroop task was used. To assess strength of inhibitory EC in alcohol-dependent patients. Participants had to decide whether the colour name and colour of the ink were same or different.

Questionnaires

Beck Depression Inventory (BD): Used to measure the severity of depressive symptoms.

Rosenberg Self-Esteem Scale (RSES): Addresses feelings of global self-worth.

Symptom Checklist 90-R (SCL90-R): Measures the physical and psychological impairment of a person within the past seven days. Indicates general level of distress.

Alcohol Abstinence Self Efficacy Scale (AASE): Assesses a patients’ confidence to stay abstinent in 20 different situations as well as their temptation to drink in these situations.

Alcohol Use Disorders Identification Test (AUDIT): A screening instrument for problematic alcohol consumption, constructed by the WHO.

Conditions and Experimental Manipulations

Participants randomly assigned to one of the two groups (training vs no training). Experimental group received 12 sessions to respond with an avoidance movement to alcohol pictures and approach movement to non-alcohol drinks. Achieved by presenting alcohol pictures in landscape format and soft drinks in portrait. During training, participants had to correct errors. Each training sessions started with a short A-AAT assessment to measure training effects of the previous session. Control group received no training at all instead of a sham-training, because no significant difference between no-training and sham-training was found in a previous study.

Procedure, study design, data analysis

First week of therapy, patients took part in a ‘neuropsychological checkup’ including the A-AAT. The previously mentioned questionnaires were also filled out, within the diagnostic phase. After pretest, patients randomly assigned to training conditions. As well as experimental manipulation, patients received treatment as usual, consisting of abstinence-oriented inpatient CBT-based treatment. One year after discharge, patients received a follow-up questionnaire about alcohol consumption since treatment.

The main outcome variable was treatment outcome one-year follow-up. Successful outcomes were 1) no relapse at all or 2) a single lapse shorter than 3 days ended by the patient without further negative consequences. ‘No success’ was defined as relapse or death, ‘no information’, or refusal.

To predict who will profit from the training, the predictive value of the implicit measure (A-AAT) and the questionnaires, as well as demographic facts, and the measure of EC were of interest.

Discussion

Main findings were that the effects of a computerized alcohol-avoidance training were replicated on the process trained and on long-term clinical outcomes. Second, this long-term effect was mediated by the change in alcohol-approach tendencies from pre- to post-test. Third, regarding moderators, the strength of alcohol-approach tendencies at pretest, but not hypothesized weakness of EC predicted the amount of change in approach-tendencies – age significantly predicted who would profit most from training.

Clinical effects of CBM in short-term and long-term were replicated. Strengthens the suggestion to add CBM to regular treatment, to supplement treatment of addictive disorders. Short-term effects were mainly due to the experimental group developing strong alcohol-avoidance bias, whereas no change in bias for soft drinks occurred. For the control group there was no change in either drink. Long-term alcohol-dependent patients are likely to feel approach (negative reinforcement effect of alcohol) and avoidance (awareness of negative long-term effects of drinking) impulses. But despite this awareness, salient situational cues may still trigger approach-tendencies in a patient in a risky situation after leaving the clinic. CBM could reduce ambivalence by strengthening avoidance impulses, weakening tendencies, and/or control over these tendencies.

Regarding long-term effects, fewer relapses occurred in the training group, and the training condition remained a significant predictor of treatment outcome. Could be argued that training only increased patients’ willingness to answer follow-up questionnaires, maybe because they liked the training/had positive memories of their stay at the clinic (social desirability). But an increased return rates in the sham-training condition was not found. It seems likely that the lack of significance is due to response bias indicating that patients are more likely to answer if they’re still abstinent.

Regarding moderation, amount of change in alcohol-approach bias was moderated by the A-AAT prescore. It makes intuitive sense that re-training of a cognitive bias has the strongest effect in participants who start the training with a strong cognitive bias. But present findings also indicate that matching on the individual level will be difficult. Hypothesis that weak EC would predict stronger effect of alcohol-avoidance training wasn’t confirmed. Was found that age moderated the treatment effect, and higher age is correlated with weaker EC.

From a broader developmental perspective, the present findings are interesting. They reject the notion that CBM can only have an influence on young malleable brains. More positive effects were found for older alcoholic patients. These findings are promising from a treatment perspective. Many individuals experiencing problems with alcohol spontaneously ‘mature out’ of these problems, also in adult community samples many individuals succeed in spontaneous recovery without formal treatment. People who enter formal treatment tend to be older and have comorbid other psychiatric problems. CBM may train control over the impulse to drink again in a concentrated way, and the alcohol-stimuli may help trigger this ability in risky situations after treatment discharge. One could also investigate training of general EC abilities. Goal-management and mindfulness training have provided initial promising results in addiction, also interventions with a cognitive training element.

Finally, though these results are promising, there are some limitations.

1. Measure of EC used here was a variety of the Stroop Task, may have been easier than the original.
2. Brain activity during the task could also be measured.
3. Both the current study and the one by Wiers et al. (2011) were conducted in the same clinic and carried out by the same research group. To draw firm conclusions about the use of this CBM as a treatment it needs to be tested in a multi-center study with different treatment facilities.
4. Success of the CBM treatment may depend on the motivation of patients.
5. Important line of future research is to identify necessary conditions for the CBM to be effective.
6. A related domain of further applied interest concerns the possibility of a ‘take-home’ training. CBM is simple and computerized, so patients could continue their training outside the clinic at home – may increase the transfer of success achieved with training.
7. Another issue concerns mediation and moderation. Present finding that age moderated the effectiveness of the A-AAT retraining is valuable when it comes to matching trainings to patient. But age correlated with a number of other potential predictors so it’s important to disentangle these variables in future studies.

Conclusion

In conclusion, CBM seems to be a promising treatment add-on for treating addiction as well as other psychopathology. Older people seem to profit most from the training, but this variable is correlated with various other variables. Next research steps should be to clarify underlying mechanisms in CBM compared to other training-interventions, and address issues of implementation. Finally, it’s important for theoretical and clinical reasons to investigate the question of moderation: which training works best for whom?