A Systematic Review of Attention Biases in Opioid, Cannabis, Stimulant Use Disorders

Be more mindful: Targeting addictive responses by integrating mindfulness with cognitive bias modification or cue exposure interventions

This review provides an overview of the most prominent neurocognitive effects of cognitive bias modification (CBM), cue-exposure therapy and mindfulness interventions for targeting addictive responses. It highlights the key insights that have stemmed from cognitive neuroscience and brain imaging research and combines these with insights from behavioural science in building a conceptual model integrating mindfulness with response-focused CBM or cue-exposure interventions. This furthers our understanding of whether and how mindfulness strategies may i) facilitate or add to the induced response-focused effects decreasing cue-induced craving, and ii) further weaken the link between craving and addictive responses. Specifically, awareness/monitoring may facilitate, and decentering may add to, response-focused effects. Combined awareness acceptance strategies may also diminish the craving-addiction link. The conceptual model presented in this review provides a specific theoretical framework to deepen our understanding of how mindfulness strategies and CBM or cue-exposure interventions can be combined to greatest effect. This is important in both suggesting a roadmap for future research, and for the further development of clinical interventions.

Measuring attentional bias in smokers during and after psychosocial stress induction with a Trier Social Stress Test in virtual reality via eye tracking

Introduction

Attentional bias (AB) is considered an important factor not only in the etiology of addiction, but also with respect to relapse. However, evidence for the predictive ability of AB for relapse is not robust. One reason for this might be fluctuations of AB due to stress. Therefore, the current study investigated whether AB was present during and after stress induction and whether AB was enhanced by stress induction.

Methods

A Virtual Reality (VR) adaptation of the Trier Social Stress Test (VR-TSST) was used to induce psychosocial stress in smokers (n = 34) and non-smokers (n = 37) followed by a novel free-viewing task in VR. Eye tracking data was recorded to examine gaze behavior to smoking-related and neutral stimuli presented in the VR-TSST and the free-viewing task.

Results

Stress ratings increased significantly from baseline to post VR-TSST in smokers and non-smokers. During the VR-TSST we observed, more frequent, longer, and earlier fixations on smoke-related compared with neutral stimuli without significant group differences. However, in the free-viewing task following the stress induction, a specific AB of smokers in terms of earlier and longer fixations on smoke stimuli was found.

Conclusion

Results indicate that AB is not a persistent trait in smokers, but is context dependent. It is suggested that emotional learning processes such as smoking in the context of relief after stress may contribute to changes of AB both in terms of increased initial attention and deeper stimulus processing. Additionally, the potential of the VR-TSST to induce psychosocial stress could be replicated.

Assessing the attentional bias of smokers in a virtual reality anti-saccade task using eye tracking

INTRODUCTION

Cognitive biases (among them attentional bias, AB) are considered an important factor in the development, maintenance, and recurrence of addiction. However, traditional paradigms to measure AB have been criticized regarding external validity and methodical issues. Therefore, and because the neurophysiological correlates of anti-saccade tasks are known, we implemented a novel smoking anti-saccade task in virtual reality (VR) to measure AB and inhibitory control in different contexts and with higher ecological validity.

METHODS

Smokers (n = 20) and non-smokers (n = 20) were tested on a classic pro- and anti-saccade task, a VR anti-saccade task and a VR attention fixation task (all containing smoking-related and neutral stimuli) while eye-tracking data was collected. Two VR contexts (park and office room) were applied.

RESULTS

Saccade latencies were significantly higher for the smoking group in the VR anti-saccade task. However, this effect did not differ between smoking-related and neutral stimuli, thus overall no AB was observed. Instead, AB was only present in the park context. Additionally, saccade latencies and error rates were significantly higher in the park context.

CONCLUSIONS

Results indicate impaired inhibitory control in smokers relative to non-smokers. The lack of evidence for a general AB might be due to the lower severity of smoking dependence in the smoking sample. Instead, results suggest context specificity of AB. Implications for smoking cessation interventions in the field of inhibitory control training and attention bias modification are discussed.

A serotonergic biobehavioral signature differentiates cocaine use disorder participants administered mirtazapine

Cocaine use disorder (CUD) patients display heterogenous symptoms and unforeseeable responses to available treatment approaches, highlighting the need to identify objective, accessible biobehavioral signatures to predict clinical trial success in this population. In the present experiments, we employed a task-based behavioral and pharmacogenetic-fMRI approach to address this gap. Craving, an intense desire to take cocaine, can be evoked by exposure to cocaine-associated stimuli which can trigger relapse during attempted recovery. Attentional bias towards cocaine-associated words is linked to enhanced effective connectivity (EC) from the anterior cingulate cortex (ACC) to hippocampus in CUD participants, an observation which was replicated in a new cohort of participants in the present studies. Serotonin regulates attentional bias to cocaine and the serotonergic antagonist mirtazapine decreased activated EC associated with attentional bias, with greater effectiveness in those CUD participants carrying the wild-type 5-HT2CR gene relative to a 5-HT2CR single nucleotide polymorphism (rs6318). These data suggest that the wild-type 5-HT2CR is necessary for the efficacy of mirtazapine to decrease activated EC in CUD participants and that mirtazapine may serve as an abstinence enhancer to mitigate brain substrates of craving in response to cocaine-associated stimuli in participants with this pharmacogenetic descriptor. These results are distinctive in outlining a richer "fingerprint" of the complex neurocircuitry, behavior and pharmacogenetics profile of CUD participants which may provide insight into success of future medications development projects.

Can intranasal oxytocin reduce craving in automated addictive behaviours? A systematic review

Existing pharmacotherapies for managing craving, a strong predictor of relapse to automated addictive behaviours, are limited in efficacy and characterised by increased health risks associated with their pharmacological profile. Preclinical studies have identified oxytocin as a promising pharmacotherapy with anticraving properties for addictive behaviours. Here, we provide the first systematic review of 17 human studies (n = 722; 30% female) investigating the efficacy of intranasal oxytocin to reduce craving or consumption in addictive behaviours. We identify intranasal oxytocin as a method that warrants further investigation regarding its capacity to decrease cue-induced, acute stress-induced or withdrawal-related craving and relapse related to alcohol, cannabis, opioids, cocaine or nicotine, including a potential role as ad hoc medication following exposure to drug-related cues. Future studies should investigate the role of factors such as treatment regimens and sample characteristics, including the role of the amygdala, which we propose as a distinct mechanism mediating oxytocin's anticraving properties.

Cognitive Bias Modification for Addictive Disorders: Emerging Knowledge and Persistent Gaps

The advances in experimental psychology have led to the discovery of unconscious, automatic biases (attentional and approach biases) that account for the lapse and relapses amongst individuals with addictive disorders. To date, there has been extensive investigation into the assessment and modification of attention biases amongst individuals with the highly prevalent substance use disorders. Alternative modalities, such as technology, has also been evaluated for the delivery of these interventions. Given this, the specific objectives of this perspective article are in highlighting the emerging knowledge that has accrued over the last three years, and in addressing several of the research gaps in the previous article. Firstly, this perspective article will examine the evidence for biases and bias modification amongst the highly prevalent substance use disorders. This article will also examine how such bias modification has been utilized clinically. Secondly, this perspective article will also examine how technology has been applied to these bias modification interventions. Thirdly, this article will also examine the literature to highlight the biological underpinnings following bias modification. Fourthly, this article also examines the limitations of existing bias modification paradigms and methods taken to better these conventional interventions. The article concludes with highlighting the outstanding gaps in the current knowledge. To date, there remains mixed evidence for the modification of attention biases; and there are a paucity of studies examining the effectiveness of mobile delivery of bias intervention. Only one study has considered patients’ perspective in the development of an intervention. There remained several gaps in the knowledge, which future research could address.

Entropy: A Promising EEG Biomarker Dichotomizing Subjects With Opioid Use Disorder and Healthy Controls

Electroencephalography (EEG) signals are known to be nonstationary and often multicomponential signals containing information about the condition of the brain. Since the EEG signal has complex, nonlinear, nonstationary, and highly random behaviour, numerous linear feature extraction methods related to the short-time windowing technique do not satisfy higher classification accuracy. Since biosignals are highly subjective, the symptoms may appear at random in the time scale and very small variations in EEG signals may depict a definite type of brain abnormality it is valuable and vital to extract and analyze the EEG signal parameters using computers. The challenge is to design and develop signal processing algorithms that extract this subtle information and use it for diagnosis, monitoring, and treatment of subjects suffering from psychiatric disorders. For this purpose, finite impulse response-based filtering process was employed rather than traditional time and frequency domain methods. Finite impulse response subbands were analyzed further to obtain feature vectors of different entropy markers and these features were fed into a classifier namely multilayer perceptron. The performances of the classifiers were finally compared considering overall classification accuracies, area under receiver operating characteristic curve scores. Our results underline the potential benefit of the introduced methodology is promising and is to be treated as a clinical interface in dichotomizing substance use disorders subjects and for other medical data analysis studies. The results also indicate that entropy estimators can distinguish normal and opioid use disorder subjects. EEG data and theta frequency band have distinctive capability for almost all types of entropies while nonextensive Tsallis entropy outperforms compared with other types of entropies.

A Smartphone Attention Bias Intervention for Individuals With Addictive Disorders: Protocol for a Feasibility Study

Background

Substance use disorders are highly prevalent globally. Relapse rates following conventional psychological interventions for substance use disorders remain high. Recent reviews have highlighted attentional and approach or avoidance biases to be responsible for multiple relapses. Other studies have reported the efficacy of interventions to modify biases. With advances in technologies, there are now mobile versions of conventional bias modification interventions. However, to date, no study has evaluated bias modification in a substance-using, non-Western sample. Existing evaluations of mobile technologies for the delivery of bias interventions are also limited to alcohol or tobacco use disorders.

Objective

This study aims to examine the feasibility of mobile-based attention bias modification intervention among treatment-seeking individuals with substance use and alcohol use disorders.

Methods

This is a feasibility study, in which inpatients who are in their rehabilitation phase of clinical management will be recruited. On each day that they are in the study, they will be required to complete a craving visual analogue scale and undertake both a visual probe-based assessment and and modification task in a smartphone app . Reaction time data will be collated for the computation of baseline attentional biases and to determine whether there is a reduction of attentional bias across the interventions. Feasibility will be determined by the number of participants recruited and participants’ adherence to the planned interventions up until the completion of their rehabilitation program and by the ability of the app in detecting baseline biases and changes in biases. Acceptability of the intervention will be assessed by a short questionnaire of users’ perceptions of the intervention. Statistical analyses will be performed using SPSS version 22.0, while qualitative analysis of the perspectives will be performed using NVivo version 10.0.

Results

This study was approved by the National Healthcare Group Domain Specific Research Board, with approval number (2018/00316). Results will be disseminated by means of conferences and publications.Currently, we are in the process of recruitment for this study.

Conclusions

To the best of our knowledge, this is the first study to evaluate the feasibility and acceptability of a mobile attention bias modification intervention for individuals with substance use disorders. The data pertaining to the feasibility and acceptability are undoubtedly crucial because they imply the potential use of mobile technologies in retraining attentional biases among inpatients admitted for medical-assisted detoxification and rehabilitation. Participants’ feedback pertaining to the ease of use, interactivity, and motivation to continue using the app is crucial because it will determine whether a codesign approach might be warranted to design an app that is acceptable for participants and that participants themselves would be motivated to use.

International Registered Report Identifier (IRRID)

PRR1-10.2196/11822

Cognitive Biases in Cannabis, Opioid, and Stimulant Disorders: A Systematic Review

Background: Opiates, cannabis, and stimulants are highly abused and are prevalent disorders. Psychological interventions are crucial given that they help individuals maintain abstinence following a lapse or relapse into substance use. The dual-process theory has posited that while the repeated use of a substance leads to increased automatic processing and increased automatic tendencies to approach substance-specific cues, in addition to the inhibition of other normal cognitive processes. Prior reviews are limited, as they failed to include trials involving participants with these prevalent addictive disorders or have not reviewed the published literature extensively. Objectives: The primary aim of this review is to synthesize the evidence for cognitive biases in opioid use, cannabis use, and stimulant use disorders. The secondary aim of the review is to determine if cognitive bias could be consistently detected using the different methods. Lastly, this review will narratively synthesize the evidence of possible associations between cognitive biases and other addiction-related outcomes. Methods: A search was conducted from November 2017 to January 2018 on PubMed, MEDLINE, Embase, PsycINFO, Science Direct, Cochrane Central, and Scopus. Articles were included if participants had a primary diagnosis of opioid use, cannabis use, or stimulant use disorder. The selection process of the articles was in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analysis guidelines. A qualitative synthesis was undertaken. Results: A total of 38 studies were identified. The main finding is the evidence that cognitive biases are present in the 38 studies identified, except for a single study on opioid use and stimulant use disorders. Cognitive biases were reported despite a variety of different methods being utilized. Synthesis of secondary outcome was not feasible, due to the varied outcomes reported. Conclusions: Cognitive biases have been consistently observed in opioid use, cannabis use, and stimulant use disorders, despite a range of assessment tools being utilized in the assessment for these biases.