Cognitive Training Effectiveness on Memory, Executive Functioning, and Processing Speed in Individuals With Substance Use Disorders: A Systematic Review

Working memory performance predicts, but does not reduce, cocaine- and cannabinoid-seeking in adult male rats

Background

Cognitive deficits reflecting impaired executive function are commonly associated with psychiatric disorders, including substance use. Cognitive training is proposed to improve treatment outcomes for these disorders by promoting neuroplasticity within the prefrontal cortex, enhancing executive control, and mitigating cognitive decline due to drug use. Additionally, brain derived neurotrophic factor (BDNF) can facilitate plasticity in the prefrontal cortex and reduce drug-seeking behaviors. We investigated whether working memory training could elevate BDNF levels in the prefrontal cortex and if this training would predict or protect against cocaine or cannabinoid seeking.

Methods

Adult male rats were trained to perform a 'simple' or 'complex' version of a delayed- match-to-sample working memory task. Rats then self-administered cocaine or the synthetic cannabinoid WIN55,212-2 and were tested for cued drug-seeking during abstinence. Tissue from the prefrontal cortex and dorsal hippocampus was analyzed for BDNF protein expression.

Results

Training on the working memory task enhanced endogenous BDNF protein levels in the prelimbic prefrontal cortex but not the dorsal hippocampus. Working memory training did not impact self-administration of either drug but predicted the extent of WIN self-administration and cocaine seeking during abstinence.

Conclusions

These results suggest that working memory training promotes endogenous BDNF but does not alter drug-seeking or drug-taking behavior. However, individual differences in cognitive performance prior to drug exposure may predict vulnerability to future drug use.

Cognitive training interventions for substance use disorders: what they really offer?

Cognitive training (CT) has emerged as a potential therapeutic approach for substance use disorders (SUD), aiming to restore cognitive impairments and potentially improve treatment outcomes. However, despite promising findings, the effectiveness of CT in real-life applications and its impact on SUD symptoms has remained unclear. This perspective article critically examines the existing evidence on CT for SUD and explores the challenges and gaps in implementing CT interventions. It emphasizes the need for clarity in expectations and decision-making from a public health standpoint, advocating for comprehensive studies that consider a broader range of SUD consequences and utilize measures that reflect patients' actual experiences.

Effectiveness of Neuropsychological Rehabilitation in the Recovery of Executive Deficits in Patients with Alcohol Use Disorder: A Systematic Review Protocol

INTRODUCTION

Changes in executive functions associated with alcohol consumption are frequently found in alcohol use disorder. Neuropsychological rehabilitation can play an essential role as an effective treatment in the recovery from these deficits, leading to the maintenance of abstinence. However, there are still some uncertainties regarding its impact on the recovery of deficits in executive functions. Our purpose is to present a protocol for a systematic review aiming to assess which neuropsychological rehabilitation programs are effective in the recovery of executive deficits in patients with alcohol use disorder.

METHODS

We will search the following databases: PubMed, Cochrane Library (CENTRAL), Web of Science, and Scopus, as well as the list of references of the identified studies. Screening, data extraction, and synthesis, as well as evaluation of the risk of bias, will be carried out by two reviewers independently, using ROBINS-I and RoB 2. Disagreements will be resolved using a third additional reviewer. Primary outcomes will correspond to changes in executive functions, following a neuropsychological rehabilitation program in patients with alcohol use disorder. The evidence will be synthesized using a narrative description of neuropsychological rehabilitation programs and the indicators of their effectiveness will be identified. The neuropsychological rehabilitation programs for executive functions will be assessed considering their different components and their impact on the recovery of these functions. The review described in this protocol will allow the development of guidelines for the design of more effective rehabilitation programs for clinical populations with alcohol use disorder.

Comparative Effects of Cognitive Rehabilitation and Photobiomodulation on Drug Craving in Treatment-Seeking Opioid Addicts

Background: Drug addiction refers to a maladaptive pattern of drug use that frequently leads to substance abuse problems and accompanying cognitive and behavioral symptoms. Among the crucial criteria of drug addiction, craving stands out as a potent factor contributing to ongoing drug abuse and relapse following period of abstinence. To date, there is no definitive method for eradicating opioid cravings. The introduction of novel neurocognitive interventions, such as cognitive rehabilitation and photobiomodulation (PBM), into the realm of psychiatric treatments holds promise due to the parallels between drug addiction and other psychiatric disorders. These innovative techniques offer potential value in addressing drug addiction. Objective: This study aimed to assess and compare the efficacy of cognitive rehabilitation and PBM in alleviating drug cravings among individuals undergoing addiction treatment in clinical settings. Methods: The research used randomized clinical trial as the chosen research method. The statistical population encompassed all clients receiving treatment for addiction at clinics, selected through the convenience sampling method, with α = 0.05 significance level and an effect size of 85%. Gpower software was utilized to determine three equal groups. Sixty-three participants, each having a mean total score higher than 3 out of 5 on the Desire for Drug Questionnaire (DDQ), were randomly assigned to two experimental groups (n = 21 each) and a control group (n = 21). For the assessment of immediate and periodic opioid craving, the DDQ and the Obsessive Compulsive Drug Use Scale were used. In the low-level laser group, an 810 nm wavelength with continuous irradiation was applied twice a week at a distance of 1 cm by 1 cm to the prefrontal part of the brain for duration of 6 weeks (12 sessions). In the brain rehabilitation group, the stop signal and n-back tasks software were used twice a week for period of 6 weeks (comprising 12 sessions, each lasting 30 min). Results: The results demonstrated that each intervention significantly reduced drug craving in both the post-test and follow-up phases compared to the control group. The Bonferroni post hoc test indicated that PBM was more effective than cognitive rehabilitation in terms of working memory (WM) and inhibitory control for reducing drug craving (p < 0.05). Conclusions: While both PBM and cognitive rehabilitation targeting WM and inhibitory control effectively reduced opioid drug craving, low-level laser therapy proved to be more effective than cognitive rehabilitation in this regard.

Cognitive training and remediation interventions for substance use disorders: a Delphi consensus study

AIMS

Substance use disorders (SUD) are associated with cognitive deficits that are not always addressed in current treatments, and this hampers recovery. Cognitive training and remediation interventions are well suited to fill the gap for managing cognitive deficits in SUD. We aimed to reach consensus on recommendations for developing and applying these interventions.

DESIGN, SETTING AND PARTICIPANTS

We used a Delphi approach with two sequential phases: survey development and iterative surveying of experts. This was an on-line study. During survey development, we engaged a group of 15 experts from a working group of the International Society of Addiction Medicine (Steering Committee). During the surveying process, we engaged a larger pool of experts (n = 54) identified via recommendations from the Steering Committee and a systematic review.

MEASUREMENTS

Survey with 67 items covering four key areas of intervention development: targets, intervention approaches, active ingredients and modes of delivery.

FINDINGS

Across two iterative rounds (98% retention rate), the experts reached a consensus on 50 items including: (i) implicit biases, positive affect, arousal, executive functions and social processing as key targets of interventions; (ii) cognitive bias modification, contingency management, emotion regulation training and cognitive remediation as preferred approaches; (iii) practice, feedback, difficulty-titration, bias modification, goal-setting, strategy learning and meta-awareness as active ingredients; and (iv) both addiction treatment work-force and specialized neuropsychologists facilitating delivery, together with novel digital-based delivery modalities.

CONCLUSIONS

Expert recommendations on cognitive training and remediation for substance use disorders highlight the relevance of targeting implicit biases, reward, emotion regulation and higher-order cognitive skills via well-validated intervention approaches qualified with mechanistic techniques and flexible delivery options.

Social Cognition in Opioid Use Disorder

Background: Opioid use disorder (OUD) is associated with significant functional impairment and neurocognitive dysfunction, but only a handful of studies have investigated social cognitive abilities in this condition. This study aimed to investigate facial emotion recognition accuracy/biases and two different aspects of theory of mind (ToM) (ToM-decoding vs ToM-reasoning) in people with recovered OUD. Methods: The participants included 32 people with recovered OUD who were on Buprenorphine + Naloxone (B/N) maintenance treatment and 32 healthy controls. In addition to neurocognitive tasks, both groups were assessed by a facial emotion recognition task, the faux pas recognition task, and the reading the mind from the eyes task. Results: In comparison to healthy controls, people on B/N maintenance treatment showed deficits in facial emotion recognition (d = 1.32) and both aspects of ToM (d = 0.87-1.21). In analyses of individual emotions, people on B/N maintenance treatment had decreased accuracy in recognition of anger and fear and had a bias to identify other emotions as sad. The duration of opioid use was robustly associated with difficulties in the recognition of anger. Conclusion: People in B/N maintenance treatment have significant difficulties in recognizing the emotions and mental states of others. Deficits in social cognition might be important for understanding the difficulties in interpersonal and social functioning in people with OUD.

Does chronic use of amphetamine-type stimulants impair interference control? - A meta-analysis

In substance use and addiction, inhibitory control is key to ignoring triggers, withstanding craving and maintaining abstinence. In amphetamine-type stimulant (ATS) users, most research focused on behavioral inhibition, but largely neglected the equally important subdomain of cognitive interference control. Given its crucial role in managing consumption, we investigated the relationship between interference control and chronic ATS use in adults. A database search (Pubmed & Web of Science) and relevant reviews were used to identify eligible studies. Effect sizes were estimated with random effects models. Subgroup, meta-regression, and sensitivity analyses explored heterogeneity in effect sizes. We identified 61 studies (53 datasets) assessing interference control in 1873 ATS users and 1905 controls. Findings revealed robust small effect sizes for ATS-related deficits in interference control, which were mainly seen in methamphetamine, as compared to MDMA users. The differential effects are likely due to tolerance-induced dopaminergic deficiencies (presumably most pronounced in methamphetamine users). Similarities between different ATS could be due to noradrenergic deficiencies; but elucidating their functional role in ATS users requires further/more research.

Substance abuse and susceptibility to false memory formation: a systematic review and meta-analysis

Background

Substance abuse has an impact on various cognitive domains, including memory. Even though this impact has been extensively examined across different subdomains, false memory has been sparsely studied. This systematic review and meta-analysis seek to synthesize the current scientific data concerning false memory formation in individuals with a history of substance abuse.

Methods

PubMed, Scopus, the Cochrane Library, Web of Science, and PsycINFO were searched to identify all experimental and observational studies in English, Portuguese, and Spanish. Studies were then examined by four independent reviewers and, if they met the inclusion criteria, assessed for their quality. The Cochrane Risk of Bias Tool for randomized controlled trials (RCT) and the Joanna Briggs Institute (JBI) critical appraisal checklists for quasi-experimental and analytic cross-sectional studies were used to assess the risk of bias.

Results

From the 443 screened studies, 27 (and two more from other sources) were considered eligible for full-text review. A final 18 studies were included in the present review. Of these, 10 were conducted with alcoholics or heavy drinkers, four focused on ecstasy/polydrug users, three were done with cannabis users and one focused on methadone maintenance patients with current cocaine dependence. Regarding false memory type, 15 studies focused on false recognition/recall, and three on provoked confabulation.

Conclusions

None but one of the studies considering false recognition/recall of critical lures found any significant differences between individuals with a history of substance abuse and healthy controls. However, most of the studies taking into account false recognition/recall of related and unrelated events found that individuals with a history of substance abuse showed significantly higher rates of false memories than controls. Future research should continue to consider different types of false memories as well as their potential association with relevant clinical variables.

Systematic review registration

https://www.crd.york.ac.uk/prospero/display_record.php?RecordID=266503, identifier: CRD42021266503.

Executive Dysfunction in Patients With Alcohol Use Disorder: A Systematic Review

A medical condition known as alcohol use disorder (AUD) is defined as an impaired capacity to reduce or regulate alcohol consumption despite negative social, occupational, or health effects. According to studies, habitual drinkers experience a reduction in their capacity to process new information, gain new skills, and formulate plans. Studies indexed in PubMed, PubMed Central, Google Scholar, ResearchGate, and ScienceDirect, published from 2012 to 2022, were identified through the search terms “alcohol use disorder” and “executive function.” A total of 2242 abstracts were identified through the initial search terms. Full texts were reviewed for 61 articles, out of which nine articles met the criteria for inclusion. This systematic review was based on the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. The current systematic review primarily focuses on the following issues: clinical neuropsychological tests of executive dysfunction, specific brain regions most affected by alcohol neurotoxic effects, and alcohol-related dementia. This review concluded that chronic alcohol dependence syndrome causes impairments in several cognitive function domains. Study shows frontal lobe damage is caused by chronic alcohol consumption. A faulty interaction among large-scale networks underlies patients' executive dysfunction in AUD, which is suggested by changes in prefrontal white-matter pathways. The goal of this systematic review is to improve the ability to recognize alcoholics who are particularly at risk of functional impairments to tailor therapeutic therapy to maximize the chance of maintaining abstinence and neuropsychology concerning this complex disease.

Effects of chess-based cognitive remediation training as therapy add-on in alcohol and tobacco use disorders: protocol of a randomised, controlled clinical fMRI trial

BACKGROUND

Alcohol and tobacco use disorders (AUD, TUD) are frequent, both worldwide and in the German population, and cognitive impairments are known to facilitate instances of relapse. Cognitive training has been proposed for enhancing cognitive functioning and possibly improving treatment outcome in mental disorders. However, these effects and underlying neurobiological mechanisms are not yet fully understood regarding AUD and TUD. Examining the effect of chess-based cognitive remediation training (CB-CRT) on neurobiological, neuropsychological and psychosocial aspects as well as treatment outcomes will provide insights into mechanisms underlying relapse and abstinence and might help to improve health behaviour in affected individuals if used as therapy add-on.

METHODS AND ANALYSIS

N=96 individuals with either AUD (N=48) or TUD (N=48) between 18 and 65 years of age will participate in a randomised, controlled clinical functional MRI (fMRI) trial. Two control groups will receive treatment as usual, that is, AUD treatment in a clinic, TUD outpatient treatment. Two therapy add-on groups will receive a 6-week CB-CRT as a therapy add-on. FMRI tasks, neurocognitive tests will be administered before and afterwards. All individuals will be followed up on monthly for 3 months. Endpoints include alterations in neural activation and neuropsychological task performance, psychosocial functioning, and relapse or substance intake. Regarding fMRI analyses, a general linear model will be applied, and t-tests, full factorial models and regression analyses will be conducted on the second level. Behavioural and psychometric data will be analysed using t-tests, regression analyses, repeated measures and one-way analyses of variance.

ETHICS AND DISSEMINATION

This study has been approved by the ethics committee of the medical faculty Mannheim of the University of Heidelberg (2017-647N-MA). The findings of this study will be presented at conferences and published in peer-reviewed journals.

TRIAL REGISTRATION

The study was registered in the Clinical Trials Register (trial identifier: NCT04057534 at clinicaltrials.gov).

Cognitive Profiles of Adolescent Inpatients with Substance Use Disorder

The prevalence of substance abuse is high during adolescence, and several studies have linked the use of alcohol and cannabis in adolescence to different cognitive impairments. To investigate whether specific cognitive deficits can be observed in adolescents with substance use disorder (SUD), we compared the cognitive profiles of inpatient adolescents diagnosed with SUD to a control group matched for sex, age and educational status. The inpatient adolescents received diagnoses of cannabis use disorder, alcohol use disorder or both. We compared the WISC-V profiles of 22 inpatients (45.5% female, M_age: 14.5; SD: 0.8) and the WAIS-IV profiles of 27 inpatients (44.4% female, M_age: 17.1; SD: 0.9) to 49 matched control participants with no diagnosed SUD. At the time of testing, participants were hospitalized for treatment of their SUD and were abstinent for a period of at least 6 weeks. To gain greater power, we jointly analyzed the Verbal Comprehension Index, Working Memory Index, Processing Speed Index and Full Scale IQ as assessed by WISC-V and WAIS-IV. The clinical group performed significantly worse than the control group on all the above indices. When only the group of inpatients was observed, in a model with the factors sex, educational status, presence of a comorbid diagnosis of depression and the number of comorbid diagnoses, only the factor educational status was significantly associated with the Full Scale IQ, whereas the factors sex and a comorbid diagnosis of depression in this group were associated with the Processing Speed Index. The results show that adolescents diagnosed with SUD (cannabis and/or alcohol) display broad cognitive impairments after 6 weeks of abstinence. Future research is required to further explore the role of comorbid diagnoses.