Johannes Lindenmeyer

Retraining Automatic Action Tendencies Changes Alcoholic Patients’ Approach Bias for Alcohol and Improves Treatment Outcome

This study tested the effects of a new cognitive-bias modification (CBM) intervention that targeted an approach bias for alcohol in 214 alcoholic inpatients. Patients were assigned to one of two experimental conditions, in which they were explicitly or implicitly trained to make avoidance movements (pushing a joystick) in response to alcohol pictures, or to one of two control conditions, in which they received no training or sham training. Four brief sessions of experimental CBM preceded regular inpatient treatment. In the experimental conditions only, patients’ approach bias changed into an avoidance bias for alcohol. This effect generalized to untrained pictures in the task used in the CBM and to an Implicit Association Test, in which alcohol and soft-drink words were categorized with approach and avoidance words. Patients in the experimental conditions showed better treatment outcomes a year later. These findings indicate that a short intervention can change alcoholics’ automatic approach bias for alcohol and may improve treatment outcome.

Approach bias modification in alcohol dependence: Do clinical effects replicate and for whom does it work best?

BACKGROUND Alcoholism is a progressive neurocognitive developmental disorder. Recent evidence shows that computerized training interventions (Cognitive Bias Modification, CBM) can reverse some of these maladaptively changed neurocognitive processes. A first clinical study of a CBM, called alcohol-avoidance training, found that trained alcoholic patients showed less relapse at one-year follow-up than control patients. The present study tested the replication of this result, and questions about mediation and moderation. METHODS 509 alcohol-dependent patients received treatment as usual (primarily Cognitive Behavior Therapy) inpatient treatment. Before and after treatment, the implicit approach bias was measured with the Alcohol Approach-Avoidance Task. Half of the patients were randomly assigned to CBM, the other half received treatment as usual only. Background variables, psychopathology and executive control were tested as possible moderating variables of CBM. One year after treatment, follow-up data about relapse were collected. RESULTS The group receiving CBM developed alcohol-avoidance behavior and reported significantly lower relapse rates at one-year follow-up. Change in alcohol-approach bias mediated this effect. Moderation analyses demonstrated that older patients and patients with a strong approach-bias at pretest profited most from CBM. CONCLUSIONS CBM is a promising treatment add-on in alcohol addiction and may counter some of the maladaptive neurocognitive effects of long-term alcoholism.

Effects of cognitive bias modification training on neural alcohol cue reactivity in alcohol dependence

OBJECTIVE In alcohol-dependent patients, alcohol cues evoke increased activation in mesolimbic brain areas, such as the nucleus accumbens and the amygdala. Moreover, patients show an alcohol approach bias, a tendency to more quickly approach than avoid alcohol cues. Cognitive bias modification training, which aims to retrain approach biases, has been shown to reduce alcohol craving and relapse rates. The authors investigated effects of this training on cue reactivity in alcohol-dependent patients. METHOD In a double-blind randomized design, 32 abstinent alcohol-dependent patients received either bias modification training or sham training. Both trainings consisted of six sessions of the joystick approach-avoidance task; the bias modification training entailed pushing away 90% of alcohol cues and 10% of soft drink cues, whereas this ratio was 50/50 in the sham training. Alcohol cue reactivity was measured with functional MRI before and after training. RESULTS Before training, alcohol cue-evoked activation was observed in the amygdala bilaterally, as well as in the right nucleus accumbens, although here it fell short of significance. Activation in the amygdala correlated with craving and arousal ratings of alcohol stimuli; correlations in the nucleus accumbens again fell short of significance. After training, the bias modification group showed greater reductions in cue-evoked activation in the amygdala bilaterally and in behavioral arousal ratings of alcohol pictures, compared with the sham training group. Decreases in right amygdala activity correlated with decreases in craving in the bias modification but not the sham training group. CONCLUSIONS These findings provide evidence that cognitive bias modification affects alcohol cue-induced mesolimbic brain activity. Reductions in neural reactivity may be a key underlying mechanism of the therapeutic effectiveness of this training.

Neural Correlates of Alcohol-Approach Bias in Alcohol Addiction: the Spirit is Willing but the Flesh is Weak for Spirits

Behavioral studies have shown an alcohol-approach bias in alcohol-dependent patients: the automatic tendency to faster approach than avoid alcohol compared with neutral cues, which has been associated with craving and relapse. Although this is a well-studied psychological phenomenon, little is known about the brain processes underlying automatic action tendencies in addiction. We examined 20 alcohol-dependent patients and 17 healthy controls with functional magnetic resonance imaging (fMRI), while performing an implicit approach-avoidance task. Participants pushed and pulled pictorial cues of alcohol and soft-drink beverages, according to a content-irrelevant feature of the cue (landscape/portrait). The critical fMRI contrast regarding the alcohol-approach bias was defined as (approach alcohol>avoid alcohol)>(approach soft drink>avoid soft drink). This was reversed for the avoid-alcohol contrast: (avoid alcohol>approach alcohol)>(avoid soft drink>approach soft drink). In comparison with healthy controls, alcohol-dependent patients had stronger behavioral approach tendencies for alcohol cues than for soft-drink cues. In the approach, alcohol fMRI contrast patients showed larger blood-oxygen-level-dependent responses in the nucleus accumbens and medial prefrontal cortex, regions involved in reward and motivational processing. In alcohol-dependent patients, alcohol-craving scores were positively correlated with activity in the amygdala for the approach-alcohol contrast. The dorsolateral prefrontal cortex was not activated in the avoid-alcohol contrast in patients vs controls. Our data suggest that brain regions that have a key role in reward and motivation are associated with the automatic alcohol-approach bias in alcohol-dependent patients.

Implementation of approach bias re-training in alcoholism-how many sessions are needed?

BACKGROUND Computerized cognitive bias modification (CBM) programs have generated promising results regarding the treatment of alcohol dependence and anxiety disorders. However, there is hardly any research yet on the implementation of alcohol-CBM into clinical practice. This article addresses the question of the optimal number of training sessions for a specific form of CBM: approach bias re-training in alcohol-dependent patients. METHODS Participants were 111 alcohol-dependent patients of an inpatient rehabilitation clinic. In addition to treatment as usual, they took part in a 12-session CBM protocol, aimed at re-training alcohol approach tendencies, with an adapted Alcohol Approach-Avoidance Task. Learning curves and 2-level fitted mean trends were analyzed. Furthermore, parameters of the fitted mean trend and information on the most effective number of training sessions were used to predict 1-year follow-up data. RESULTS Two-level analyses revealed 6 training sessions to be the mean optimum, yet many patients improve further after that. Prediction of the individual optimum (speed of response) and parameters of the fitted mean trends failed. The linear term of the graph describing the mean trend of training effects, but not the speed of response, predicted 1-year follow-up data. CONCLUSIONS Suggestions for practical implementations of CBM are discussed.

Effects of cognitive bias modification training on neural signatures of alcohol approach tendencies in male alcohol-dependent patients

Alcohol‐dependent patients have been shown to faster approach than avoid alcohol stimuli on the Approach Avoidance Task (AAT). This so‐called alcohol approach bias has been associated with increased brain activation in the medial prefrontal cortex and nucleus accumbens. Cognitive bias modification (CBM) has been used to retrain the approach bias with the clinically relevant effect of decreasing relapse rates one year later. The effects of CBM on neural signatures of approach/avoidance tendencies remain hitherto unknown. In a double‐blind placebo‐controlled design, 26 alcohol‐dependent in‐patients were assigned to a CBM or a placebo training group. Both groups performed the AAT for three weeks: in CBM training, patients pushed away 90 percent of alcohol cues; this rate was 50 percent in placebo training. Before and after training, patients performed the AAT offline, and in a 3 T magnetic resonance imaging scanner. The relevant neuroimaging contrast for the alcohol approach bias was the difference between approaching versus avoiding alcohol cues relative to soft drink cues: [(alcohol pull > alcohol push)  > (soft drink pull > soft drink push)]. Before training, both groups showed significant alcohol approach bias‐related activation in the medial prefrontal cortex. After training, patients in the CBM group showed stronger reductions in medial prefrontal cortex activation compared with the placebo group. Moreover, these reductions correlated with reductions in approach bias scores in the CBM group only. This suggests that CBM affects neural mechanisms involved in the automatic alcohol approach bias, which may be important for the clinical effectiveness of CBM.

Mediation of Cognitive Bias Modification for Alcohol Addiction via Stimulus‐Specific Alcohol Avoidance Association

BACKGROUND Cognitive bias modification (CBM) studies have provided evidence that cognitive biases play a causal role in alcohol use disorders. In this study, data from a CBM experiment in alcoholic patients were re-analyzed. In the original study, no mediation by associations measured with an Implicit Association Test (IAT) was found. In this study, we explored the possibility that relevant alcohol-related automatic processes may be cue-specific. METHODS Data from a previous clinical study in a sample of 214 alcohol-addicted patients were re-analyzed. Patients were assigned to a CBM intervention or control condition, performed an alcohol-approach IAT, and were followed up for relapse data a year after training. In this study, bias scores measured via the IAT were calculated and analyzed separately for different stimulus categories: Alcohol, Soft drink, Approach, and Avoid. RESULTS Training reversed the alcohol-approach bias for all categories. This reversal of bias also predicted reduced relapse, but involved a complex stimulus category-dependent pattern in which an avoidance bias for Alcohol stimuli was most predictive of reduced relapse. CONCLUSIONS The results contribute to evidence that CBM indeed affects relapse probability via changes in automatic processes, although future study is needed to determine the precise nature of mediating processes. Automatic processes underlying alcohol-related associations may be stimulus-specific, which may be important for the methods of future studies involving implicit measures.

Decreased gray matter volume in inferior frontal gyrus is related to stop-signal task performance in alcohol-dependent patients.

Impairment in inhibitory control has been proposed to contribute to habitual alcohol use, abuse and eventually dependence. Moreover, alcohol-dependent (AD) patients have shown a loss of gray matter volume (GMV) in the brain, specifically in prefrontal regions associated with executive functions, including response inhibition. To date, no study has evaluated whether this prefrontal GMV reduction is related to response inhibition in alcohol dependence. To address this issue, we acquired high-resolution T1-weighted magnetic resonance mages from recently detoxified AD patients (n = 22) and healthy controls (HC; n = 21). Differences in local GMV between groups were assessed by means of voxel-based morphometry (VBM). Moreover, within the AD group, mean local GMV reductions were extracted and correlated with behavioral performance on the stop-signal task. We found a significantly decrease in GMV in the left inferior frontal gyrus (IFG) in AD patients compared with HC subjects. Further, mean local GMV in this area correlated positively with reaction times on go trials during the stop-signal task in AD patients. Our findings suggest that GMV losses in the IFG in AD patients are related to faster go responses on the stop-signal task.

A clinical trial with combined transcranial direct current stimulation and alcohol approach bias retraining.

Two studies showed an improvement in clinical outcomes after alcohol approach bias retraining, a form of Cognitive Bias Modification (CBM). We investigated whether transcranial direct current stimulation (tDCS) could enhance effects of CBM. TDCS is a neuromodulation technique that can increase neuroplasticity and has previously been found to reduce craving. One hundred alcohol‐dependent inpatients (91 used for analysis) were randomized into three experimental groups in a double‐blind parallel design. The experimental group received four sessions of CBM while receiving 2 mA of anodal tDCS over the dorsolateral prefrontal cortex (DLPFC). There were two control groups: One received sham stimulation during training and one received active stimulation at a different moment. Treatment outcomes were abstinence duration (primary) and relapse after 3 and 12 months, craving and approach bias (secondary). Craving and approach bias scores decreased over time; there were no significant interactions with experimental condition. There was no effect on abstinence duration after three months (χ2(2) = 3.53, p = 0.77). However, a logistic regression on relapse rates after one year (standard outcome in the clinic, but not‐preregistered) showed a trend when relevant predictors were included; relapse was lower in the condition receiving active stimulation during CBM only when comparing to sham stimulation (B = 1.52, S.E. = .836, p = .07, without predictors: p = .19). No strong evidence for a specific enhancement effect of tDCS on CBM was found. However, in a post‐hoc analysis, tDCS combined with CBM showed a promising trend on treatment outcome. Important limitations are discussed, and replication is necessary to find more reliable effects.

änderungssensitivität und prognostische Validität der MATE Indizes

Fragestellung: Neben der Behandlungsallokation (Triage) ist eine wesentliche Aufgabe des Instruments Measurements in the Addictions for Triage and Evaluation (MATE) die Anwendung in der Evaluation in Therapieverlauf und Katamnese. In diesem Aufsatz werden daher Anderungssensitivitat und prognostische Validitat des MATE auf den beiden Ebenen der Mittelwerts- wie der individuellen Veranderungen gepruft. Hinzu kommt die Frage der prognostischen Aussagefahigkeit der MATE-Indizes hinsichtlich der Abstinenz. Methodik: Bei einer Teilstichprobe (n=113) aus dem deutschen MATE Projekt wurde der MATE in einer Suchtfachklinik zur Entwohnungsbehandlung fur alkoholabhangige Patienten zu Beginn und am Ende der Behandlung eingesetzt. Auserdem wurden katamnestische Daten einer Routinekatamnese nach einem Jahr erhoben. Fur die Pra-Post-Differenzen der MATE-Scores berechneten wir Cohen’s d sowie das Standardized Response Mean (SRM). Daruber hinaus ermittelten wir die Verteilung individueller Veranderungen anhand der...