Understanding drug addiction: a neuropsychological perspective

Increasing the smoking cessation success rate by enhancing improvement of self-control through sleep-amplified memory consolidation: protocol of a randomized controlled, functional magnetic resonance study

BACKGROUND

Tobacco use disorder (TUD) remains a global health crisis characterized by high relapse rates despite extensive cessation efforts. This study aims to enhance treatment outcomes by addressing the cognitive and neural imbalances associated with habitual and goal-directed behaviours among individuals with TUD. We hypothesise that by integrating high-intensity interval training (HIIT), cognitive remediation treatment (CRT) via app-based chess training and a standard smoking cessation program (SCP) for cognitive control and sleep quality will be improved, thereby facilitating smoking cessation.

METHODS

The study will enrol 140 treatment-seeking smokers aged 18-65 years who meet the DSM-5 criteria for TUD. The participants will be randomly assigned to four groups: CRT + HIIT in the morning, CRT + HIIT in the evening, HIIT alone in the morning, and HIIT alone in the evening. Assessments will be conducted at baseline (T1), postintervention (T2), and at a three-month follow-up (T3) at the Central Institute of Mental Health in Mannheim, Germany. The primary outcomes include abstinence days or amount of alcohol consumed in cases of relapse, as well as craving reduction. Secondary outcomes include improvements in cognitive functions (working memory, response inhibition, and cognitive control), measured through neuropsychological tasks, functional magnetic resonance imaging (fMRI), polysomnography, and self-report questionnaires. The repeated-measures design allows for within-subject comparisons to evaluate intervention effectiveness.

DISCUSSION

This study aims to provide insights into the mechanisms through which combined CRT and evening HIIT, alongside improvements in sleep quality, can enhance smoking cessation outcomes. The hypothesised benefits on cognitive control and neural activity changes are expected to support better treatment adherence and reduced relapse rates among individuals with TUD. Addressing potential challenges such as high dropout rates through comprehensive participant support is crucial for the study's success. Findings from this research could inform future therapeutic strategies for TUD, potentially advancing addiction treatment approaches. The integration of novel interventions with established cessation programs underscores the study's significance in exploring holistic approaches to improving public health outcomes related to tobacco addiction.

TRIAL REGISTRATION

Registered at clinicaltrials.gov/ct2/show/NCT05726045 (Date 04.04.2024).

Neuropsychological parameters in male offenders with substance use disorders

Introduction

The impact of cognitive functions on treatment outcomes in forensic psychiatric patients with substance use disorders is not well understood. This study investigates whether neuropsychological deficits, such as in attention, executive functions, and social-emotional cognition, are associated with impulsivity and criminal history.

Methods

109 male patients with substance use disorders at the Clinic for Forensic Psychiatry in Rostock were screened using inclusion and exclusion criteria, with 30 consenting to participate. The tests included the Cambridge Neuropsychological Test Automated Battery (CANTAB) to assess cognitive functions in the areas of attention, psychomotor speed, social and emotional perception, and executive functions, with a particular focus on decision making, planning and problem solving. The Barratt Impulsiveness Scale (BIS-11) was used to measure impulsiveness.

Results

Participants displayed significantly higher impulsivity levels on the BIS-11 compared to the general population and showed marked deficits in attention, psychomotor speed, and executive functions. There was a minimal correlation between impulsivity and cognitive performance, suggesting that impulsivity does not directly predict cognitive impairments. Notably, extensive criminal histories correlated with poorer cognitive performance, particularly in tasks requiring planning and problem-solving.

Discussion

We found mixed support for the hypothesized associations between neuropsychological functions and criminal histories among patients with substance use disorders. While tasks related to planning and sustained attention showed clearer links, broader cognitive functions displayed inconsistent correlations. These findings emphasize the complexity of the relationship between cognitive deficits, impulsivity, and criminal history, highlighting the necessity for tailored assessments and rehabilitation strategies to enhance outcomes. Future research should focus on larger, longitudinal studies to validate these findings and refine therapeutic approaches.

Neurodevelopmental Impairments in Adult Psychosomatic Patients

Background/Objectives: Neuropsychological, neurodevelopmental, or minimal cerebral dysfunctions (MCD) can be found in many patients with mental disorders. They can be masked by other symptoms, impair the course of the illness, and impair work and social participation. Despite a long history of research, there is still a lack of data on the spectrum, prevalence, and consequences of these dysfunctions in patients with chronic illness. In this study, we compared patients with and without a history of neurocognitive problems in childhood for present neuropsychological dysfunctions. Methods: A convenience sample of 1453 psychosomatic inpatients completed the MCD scale, assessing neurodevelopmental issues in childhood and current neuropsychological dysfunctions. Additional assessments were the Attention Deficit Hyperactivity Self Rating Scale (ADHS-SB) and the Symptom Checklist 90 (SCL-90). Results: Significant early neurodevelopmental problems were reported by 8.87% of the patients. This group also reported a significantly higher rate of MCD symptoms and general psychosomatic symptoms (SCL-90) as compared with other patients. Conclusions: There is a notable prevalence of neuropsychological dysfunctions in psychosomatic patients in general, and especially in those with early neurodevelopmental problems. To adequately address specific potentially participation-relevant impairments, a broader diagnostic approach is necessary, including exploration of MCD history and present neuropsychological dysfunctions.

Identifying the role of (dis)inhibition in the vicious cycle of substance use through ecological momentary assessment and resting-state fMRI

Functional inhibition is known to improve treatment outcomes in substance use disorder (SUD), potentially through craving management enabled by underlying cerebral integrity. Whereas treatment is challenged by a multitude of substances that patients often use, no study has yet unraveled if inhibition and related cerebral integrity could prevent relapse from multiples substances, that is, one's primary drug of choice and secondary ones. Individuals with primary alcohol, cannabis, or tobacco use disorders completed intensive Ecological Momentary Assessment (EMA) coupled with resting-state functional MRI (rs-fMRI) to characterize the extent to which inhibition and cerebral substrates interact with craving and use of primary and any substances. Participants were 64 patients with SUD and 35 healthy controls who completed one week EMA using Smartphones to report 5 times daily their craving intensity and substance use and to complete Stroop inhibition testing twice daily. Subsamples of 40 patients with SUD and 34 control individuals underwent rs-fMRI. Mixed Model Analysis revealed that reported use of any substance by SUD individuals predicted later use of any and primary substance, whereas use of the primary substance only predicted higher use of that same substances. Craving and inhibition level independently predicted later use but did not significantly interact. Preserved inhibition performance additionally influenced use indirectly by mediating the link between subsequent uses and by being linked to rs-fMRI connectivity strength in fronto-frontal and cerebello-occipital connections. As hypothesized, preserved inhibition performance, reinforced by the integrity of inhibitory neurofunctional substrates, may partake in breaking an unhealthy substance use pattern for a primary substance but may not generalize to non-target substances or to craving management.

Successful word retraining, maintenance and transference of practice to everyday activities: A single case experimental design in early onset alcohol-induced brain damage

Word retraining programs have been shown to improve naming ability post-stroke and in progressive aphasias. Here, we investigated benefits for a 22-year-old Danish man (DJ), whose difficulties followed brain damage from heavy alcohol misuse. Using a multiple baseline-across-behaviours design (target behaviour: retrieval of word list items), DJ completed a 4-week "Look, Listen, Repeat" program on a computer. Ninety personally relevant target words were selected to create three matched lists. List 1 was trained for 10 sessions over 2 weeks, followed by 9 sessions for List 2 over 2 weeks, while the third list remained untrained. Naming performance was evaluated at baseline, during the intervention, and at 1 and 4 months post-training. Naming improved following each intervention block (p < .001), with only one data point overlapping between the baseline and treatment phases for trained items. Untrained words remained unchanged (p = 1.00), with 50% of data points non-overlapping across baseline to treatment phases. Performance was maintained over time, and appeared to generalize, with DJ naming more trained objects in their natural setting (85%) than untrained items (64%). While more evidence is needed, brief (20-minute), intensive (5-day/week) word retraining programs may assist word retrieval for people with brain damage associated with alcohol misuse.

Predictors of cognitive functioning in presentations to a community-based specialist addiction neuropsychology service

INTRODUCTION

Cognitive impairment is common in individuals presenting to alcohol and other drug (AOD) settings and the presence of biopsychosocial complexity and health inequities can complicate the experience of symptoms and access to treatment services. A challenge for neuropsychologists in these settings is to evaluate the likely individual contribution of these factors to cognition when providing an opinion regarding diagnoses such as acquired brain injury (ABI). This study therefore aimed to identify predictors of cognitive functioning in AOD clients attending for neuropsychological assessment.

METHODS

Clinical data from 200 clients with AOD histories who attended for assessment between 2014 and 2018 were analysed and a series of multiple regressions were conducted to explore predictors of cognitive impairment including demographic, diagnostic, substance use, medication, and mental health variables.

RESULTS

Regression modelling identified age, gender, years of education, age of first use, days of abstinence, sedative load, emotional distress and diagnoses of ABI and developmental disorders as contributing to aspects of neuropsychological functioning. Significant models were obtained for verbal intellectual functioning (Adj R2 = 0.19), nonverbal intellectual functioning (Adj R2 = 0.10), information processing speed (Adj R2 = 0.20), working memory (Adj R2 = 0.05), verbal recall (Adj R2 = 0.08), visual recall (Adj R2 = 0.22), divided attention (Adj R2 = 0.14), and cognitive inhibition (Adj R2 = 0.07).

CONCLUSIONS

These findings highlight the importance of careful provision of diagnoses in clients with AOD histories who have high levels of unmet clinical needs. They demonstrate the interaction of premorbid and potentially modifiable comorbid factors such as emotional distress and prescription medication on cognition. Ensuring that modifiable risk factors for cognitive impairment are managed may reduce experiences of cognitive impairment and improve diagnostic clarity.

Impulsivity as a Risk Factor for Addictive Disorder Severity during the COVID-19 Lockdown: Results from a Mixed Quantitative and Qualitative Study

Interindividual differences in personality traits, especially impulsivity traits, are robust risk factors for addictive disorders. However, their impact on addictive disorders during the COVID-19 lockdown remains unknown. This study assessed patients being followed for addictive disorders before the lockdown. We aimed to determine whether impulsivity traits (i.e., negative- and positive urgency) were associated with addictive disorders severity during the lockdowns. We also explored the patients' subjective experiences, focusing on high versus low impulsivity. The quantitative study assessed 44 outpatients consulting for addictive disorders, for impulsivity, emotion regulation, anxiety/depression, and their addictive disorder characteristics, using self-administered questionnaires. In the qualitative study, six patients from the quantitative study were assessed using guided interviews. We observed that higher negative and positive urgencies were associated with addictive disorder severity. The subjective experiences of patients during the lockdowns differed according to their emotion-related impulsivity: high versus low. Low impulsive patients used online technologies more effectively to maintain follow-up, with more positive reappraisal. In contrast, highly impulsive patients reverted more frequently to self-medication with substances and/or behaviors, more social isolation, and found coping with negative emotions more challenging. Overall, the patient's ability to cope with stressful events, like the COVID-19 lockdown, depended on their emotion-related impulsivity.

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).

Substance-induced psychosis and cognitive functioning: A systematic review

Longitudinal studies of substance-induced psychosis (SIP) suggest that approximately 11-46% of persons will progress to schizophrenia with differential risk of progression depending on the type of substance used. The findings suggest SIP may be a distinct variant of a psychotic disorder, yet SIP is understudied and the disease expression is not well characterized, particularly the cognitive phenotype. There is some evidence for cognitive dysfunction in SIP, but a synthesis of this literature has not been undertaken. We systematically reviewed all empirical research (up to December 31, 2020) that examined cognition in SIP using clinical neuropsychological measures. The cognitive outcomes are summarized by type of SIP (methamphetamine, other stimulants, alcohol, cannabis, undifferentiated). There was evidence for global and domain-specific cognitive dysfunction in SIP compared to controls and non-psychotic persons who use substances. Impairments were of similar magnitude compared to persons with schizophrenia. Delineation of a specific cognitive profile in SIP was precluded by lack of literature with comparable study designs and outcomes. Variation in visual-based cognition may be a distinct feature of SIP, but this requires further investigation. More rigorously controlled studies of cognition in SIP are needed to inform differential diagnosis and identify the unique clinical needs of this population.

Cocaine use in university students: relationships with demographics, mental health, risky sexual practices, and trait impulsivity

BACKGROUND

Cocaine is increasingly used on a recreational basis by the general population with potential implications for mental health. The aim of this study was to assess how common cocaine use is, and its mental health associations, in a large sample of university students.

METHODS

Approximately 10 000 university students were invited to take part in an online survey, which assessed the use of cocaine (ever or past year), alcohol and drug use, mental health issues, and impulsive and compulsive tendencies. Group differences in demographic and clinical characteristics were characterized.

RESULTS

A total of 3520 university students (57.7% female) completed the survey. Of these, 110 students (3.1%) reported using cocaine in the preceding year, and a further 163 students (4.6%) reported historical use more than a year ago. Cocaine use was associated with more years as a student, lower grade point averages, more use of other drugs, riskier sexual practices, post-traumatic stress disorder, attention deficit hyperactivity disorder, treatment for psychological/emotional problems (including taking prescribed medication), and trait impulsivity. Of these associations, the link with trait impulsivity had the largest effect size.

CONCLUSION

History of cocaine use appears relatively common in university students; and has a number of untoward associations in terms of mental health, use of other substances, and risky sexual practices. The most marked finding (in terms of effect size) was the link between cocaine use and trait impulsivity, supporting the importance of this construct in seeking out candidate vulnerability markers for use of cocaine and other drugs. Future work should use longitudinal designs to further characterize the nature of these associations.

The Effects of Combined Physical and Cognitive Training on Inhibitory Control: A Systematic Review and Meta-Analysis

While strong inhibitory control is critical for health and wellbeing, there are no broadly applicable effective behavioural interventions that enhance it. This meta-analysis examined the neurocognitive rationale for combined physical and cognitive training and synthesised the rapidly growing body of evidence examining combined paradigms to enhance inhibitory control. Across the research to date, there was a small positive effect (n studies = 16, n participants = 832) of combined training on improving inhibitory control. Sub-group analyses showed small-moderate positive effects when the physical component of the combined training was moderately intense, as opposed to low or vigorous intensities; moderate positive effects were found in older adults, as compared to adolescents and adults; and healthy individuals and those with vascular cognitive impairment, as compared to ADHD, ASD, mild cognitive impairment and cancer survivors. This is the first meta-analysis to provide evidence that combined physical, specifically when moderately intense, and cognitive training has the capacity to improve inhibitory control, particularly when delivered to healthy individuals and those experiencing age-related decline.

Cannabis and Illicit Drug Use During Neurodevelopment and the Associated Structural, Functional and Cognitive Outcomes: Protocol for a Systematic Review

Background

High rates of cannabis and illicit drug use are experienced by young people during the final stages of neurodevelopment (aged 15-24 years), a period characterized by high neuroplasticity. Frequent drug use during this time may interfere with neurophysiological and neuropsychological development pathways, potentially leading to ongoing unfavorable neuroadaptations. The dose-response relationship between illicit drug use, exposure, and individual neurodevelopmental variation is unknown but salient with global shifts in the legal landscape and increasingly liberal attitudes and perceptions of the harm caused by cannabis and illicit drugs.

Objective

This systematic review aims to synthesize longitudinal studies that investigate the effects of illicit drug use on structural, functional, and cognitive brain domains in individuals under the neural age of adulthood (25 years). This protocol outlines prospective methods that will facilitate an exhaustive review of the literature exploring pre- and post-drug use brain abnormalities arising during neurodevelopment.

Methods

Five electronic databases (Medline, Embase, PsycINFO, ProQuest Central, and Web of Science) will be systematically searched between 1990 and 2019. The search terms will be a combination of MeSH (Medical Subject Headings), with keywords adapted to each database. Study reporting will follow the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, and if relevant, study quality will be assessed using the Grades of Recommendation, Assessment, Development, and Evaluation (GRADE) approach. Eligible studies are those that sampled youth exposed to cannabis or illicit drugs and employed neurophysiological or neuropsychological assessment techniques. Studies will be excluded if participants had been clinically diagnosed with any psychiatric, neurological, or pharmacological condition.

Results

This is an ongoing review. As of February 2020, papers are in full-text screening, with results predicted to be complete by July 2020.

Conclusions

Integrating data collected on the three brain domains will enable an assessment of the links between structural, functional, and cognitive brain health across individuals and may support the early detection and prevention of neurodevelopmental harm.

Trial Registration

PROSPERO CRD42020151442; https://www.crd.york.ac.uk/prospero/display_record.php?RecordID=151442

International Registered Report Identifier (IRRID)

PRR1-10.2196/18349

Improving SBIRT in a nurse-managed clinic serving homeless patients with substance use disorder

A nurse-managed clinic in Northeast Tennessee that mainly serves unstably housed patients launched a process improvement project to evaluate Screening, Brief Intervention, and Referral to Treatment (SBIRT) implementation and use. These findings could guide future SBIRT efforts among vulnerable groups.

Cognitive Training for the Treatment of Addictions Mediated by Information and Communication Technologies (ICT)

This work constitutes a narrative review of the state of knowledge and advances in the intervention and treatment of addictions through the use of information and communication technologies, considering the growing demand for virtuality-mediated strategies that facilitate the approach of problems of public health such as addictions, which increase considerably year after year. To this end, the reader will be provided with a current overview of the drug use trend; subsequently, a conceptualization of the concept of addiction and its understanding from a neurobiological perspective and, finally, the progress in terms of intervention processes and therapeutic approach will be presented; which will imply an approach to the concept of e-health and rehabilitation mediated by information and communication technologies (ICT).

Brain Structure Alterations in Poly-Drug Use: Reduced Cortical Thickness and White Matter Impairments in Regions Associated With Affective, Cognitive, and Motor Functions

Substance use disorders (SUDs) are defined by obsessive and uncontrolled consumption, which is related to neurobiological changes. Based on previous work, this study investigated potential alterations in brain structure in poly-drug use disordered (PUD) patients in comparison to controls from the normal population. This study involved a sample of 153 right-handed men aged between 18 and 41 years, comprising a clinical group of 78 PUD and a group of 75 healthy controls. Group differences in gray matter (GM) and white matter (WM), as well as cortical thickness (CT), were investigated by means of diffusion tensor imaging using automated fiber quantification (AFQ) and voxel-based morphometry. We observed significant WM impairments in PUD, especially in the bilateral corticospinal tracts and the inferior longitudinal fasciculi. Furthermore, we found reduced CT in the PUD group especially in the left insular and left lateral orbitofrontal cortex. There were no group differences in GM. In addition, PUD exhibited a higher amount of psychiatric symptoms (Brief Symptom Inventory) and impairments in cognitive functions (Wonderlic Personnel Test). In line with previous research, this study revealed substantial impairments in brain structure in the PUD group in areas linked with affective, cognitive, and motor functions. We therefore hypothesize a neurologically informed treatment approach for SUD. Future studies should consequently explore a potential positive neuroplasticity in relation to a better therapeutic outcome.

A comparison of implicit and explicit reward learning in low risk alcohol users versus people who binge drink and people with alcohol dependence

Chronic alcohol use leads to specific neurobiological alterations in the dopaminergic brain reward system, which probably are leading to a reward deficiency syndrome in alcohol dependence. The purpose of our study was to examine the effects of such hypothesized neurobiological alterations on the behavioral level, and more precisely on the implicit and explicit reward learning. Alcohol users were classified as dependent drinkers (using the DSM-IV criteria), binge drinkers (using criteria of the USA National Institute on Alcohol Abuse and Alcoholism) or low-risk drinkers (following recommendations of the Scientific board of trustees of the German Health Ministry). The final sample (n = 94) consisted of 36 low-risk alcohol users, 37 binge drinkers and 21 abstinent alcohol dependent patients. Participants were administered a probabilistic implicit reward learning task and an explicit reward- and punishment-based trial-and-error-learning task. Alcohol dependent patients showed a lower performance in implicit and explicit reward learning than low risk drinkers. Binge drinkers learned less than low-risk drinkers in the implicit learning task. The results support the assumption that binge drinking and alcohol dependence are related to a chronic reward deficit. Binge drinking accompanied by implicit reward learning deficits could increase the risk for the development of an alcohol dependence.

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Alcohol dependent patients were impaired in implicit and explicit reward learning.

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Alcohol dependence may lead to implicit and explicit reward learning deficits.

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Binge drinkers learned less than low-risk drinkers in the implicit learning task.

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Binge drinking is related to implicit reward learning deficits.

Predicting Alcohol Misuse Among Australian 19-Year-Olds from Adolescent Drinking Trajectories

BACKGROUND

Alcohol use in adolescence predicts future alcohol misuse. However, the extent to which different patterns of adolescent use present risk remains unclear.

OBJECTIVES

This study investigated how adolescent trajectories of alcohol consumption during the school years predict alcohol misuse at age 19 years.

METHODS

Data were drawn from 707 students from Victoria, Australia, longitudinally followed for 7 years. Five alcohol use trajectories were identified based on the frequency of alcohol use from Grade 6 (age 12 years) to Grade 11 (age 17 years). At age 19 years, participants completed measures indicating Heavy Episodic Drinking (HED), dependency - Alcohol Use Disorders Identification Test (AUDIT) and social harms.

RESULTS

At 19 years of age, 64% of participants reported HED, 42% high AUDIT scores (8+), and 23% social harms. Participants belonging to a steep escalator trajectory during adolescence had twice the odds at 19 years of age of high AUDIT scores and social harms, and three times greater odds of HED than participants whose alcohol use slowly increased. Stable moderate consumption was also associated with an increased risk of HED compared to slowly increasing use. Abstinence predicted a reduced likelihood of all forms of misuse at 19 years of age compared to slowly increased alcohol use.

CONCLUSIONS

Trajectories of drinking frequency during adolescence predict alcohol misuse at age 19 years. Although rapid increasing use presents the greatest risk, even slowly increasing drinking predicts increased risk compared to abstinence. The findings indicate that alcohol policies should recommend nonuse and reduced frequency of use during adolescence.

Life History Theory and Recovery From Substance Use Disorder

Recovery has emerged as an important paradigm in addictions treatment but the field has yet to achieve consensus on how it should be defined and measured. The recovery construct has been extended beyond sustained reductions in use or abstinence to enhancements in global health/well-being and also prosocial community reintegration. However, few studies have included these broader domains in their measurement of recovery and few scientific theories have been advanced to explain why reductions in substance use occasion these broader life changes. This article applies life history theory to recovery for the first time to help define recovery, advance recovery measurement, and explain why broad change across multiple life domains should facilitate sustained recovery progress. We conclude with a discussion of future directions and challenges for future research informed by our life history framework for recovery.

The neuropsychopharmacology of cannabis: A review of human imaging studies

The laws governing cannabis are evolving worldwide and associated with changing patterns of use. The main psychoactive drug in cannabis is Δ⁹-tetrahydrocannabinol (THC), a partial agonist at the endocannabinoid CB₁ receptor. Acutely, cannabis and THC produce a range of effects on several neurocognitive and pharmacological systems. These include effects on executive, emotional, reward and memory processing via direct interactions with the endocannabinoid system and indirect effects on the glutamatergic, GABAergic and dopaminergic systems. Cannabidiol, a non-intoxicating cannabinoid found in some forms of cannabis, may offset some of these acute effects. Heavy repeated cannabis use, particularly during adolescence, has been associated with adverse effects on these systems, which increase the risk of mental illnesses including addiction and psychosis. Here, we provide a comprehensive state of the art review on the acute and chronic neuropsychopharmacology of cannabis by synthesizing the available neuroimaging research in humans. We describe the effects of drug exposure during development, implications for understanding psychosis and cannabis use disorder, and methodological considerations. Greater understanding of the precise mechanisms underlying the effects of cannabis may also give rise to new treatment targets.

Neuropsychiatric characterization of individuals with inhalant use disorder and polysubstance use according to latent profiles of executive functioning

BACKGROUND

Inhalant use disorder (IUD) is associated with deficits in executive functions (EFs). We described latent profiles of EFs and distribution of neuropsychiatric disorders and patterns of severity of use across these profiles.

METHODS

Individuals with IUD were recruited at community-based residential facilities for substance use treatment in Mexico City. Latent profile analysis was conducted with the following tasks: self-ordered pointing, Stroop, Iowa gambling, Wisconsin Card Sorting and Tower of Hanoi.

RESULTS

Three latent profiles were extracted from n = 165: lowest performances of inhibition of response and processing speed; lowest performance of self-monitoring, intermediate performance of inhibition of response and relatively spared processing speed; and intermediate performance of processing speed and self-monitoring, and relatively spared inhibition of response.

CONCLUSION

Between-group differences were observed mainly for antisocial personality disorder and lifetime suicidal. Findings remark the need for identifying distinct profiles of EFs within these populations to better understand the transdiagnostic heterogeneity of EFs.

Regional cerebral blood flow in opiate dependence relates to substance use and neuropsychological performance

Neuroimaging of opiate-dependent individuals indicates both altered brain structure and function. Magnetic resonance-based arterial spin labeling has been used to measure noninvasively cerebral blood flow (i.e. perfusion) in alcohol, tobacco and stimulant dependence; only one arterial spin labeling paper in opiate-dependent individuals demonstrated frontal and parietal perfusion deficits. Additional research on regional brain perfusion in opiate dependence and its relationship to cognition and self-regulation (impulsivity, risk taking and decision making) may inform treatment approaches for opiate-dependent individuals. Continuous arterial spin labeling magnetic resonance imaging at 4 T and neuropsychological measures assessed absolute brain perfusion levels, cognition and self-regulation in 18 cigarette smoking opiate-dependent individuals (sODI) stable on buprenorphine maintenance therapy. The sODI were compared with 20 abstinent smoking alcohol-dependent individuals (a substance-dependent control group), 35 smoking controls and 29 nonsmoking controls. sODI had lower perfusion in several cortical and subcortical regions including regions within the brain reward/executive oversight system compared with smoking alcohol-dependent individuals and nonsmoking controls. Perfusion was increased in anterior cingulate cortex and globus pallidus of sODI. Compared with all other groups, sODI had greater age-related declines in perfusion in most brain reward/executive oversight system and some other regions. In sODI, lower regional perfusion related to greater substance use, higher impulsivity and weaker visuospatial skills. Overall, sODI showed cortical and subcortical hypoperfusion and hyperperfusion. Relating to neuropsychological performance and substance use quantities, the frontal perfusion alterations are clinically relevant and constitute potential targets for pharmacological and cognitive-based therapeutic interventions to improve treatment outcome in opiate dependence.

Intellectual Functioning in In-Patients with Substance Use Disorders: Preliminary Results from a Clinical Mediation Study of Factors Contributing to IQ Variance

AIMS

To investigate the direct effect of different childhood difficulties on adult intelligence coefficient (IQ) and their possible indirect effect through the mediating pathways of education and severity substance use.

PARTICIPANTS

Ninety in-patients aged 19-64. The participants had abstained from substance use for at least 6 weeks and had different substance use profiles.

MEASUREMENTS

Substance use disorder (SUD) and psychiatric illnesses were diagnosed according to the International Classification of Diseases 10th edition criteria. IQ was measured with the Wechsler Adult Intelligence Scale, 4th edition. Childhood difficulties, severity of substance use and level of education were assessed through a self-report questionnaire.

FINDINGS

Mean full scale IQ for the studied population was 87.3. Learning and attention deficit/hyperactivity difficulties in childhood were directly related to adult IQ. Education had a mediating effect between childhood learning difficulties/conduct problems and the verbal comprehension index. There was no significant difference in IQ due to the specific substance used or severity of substance use.

CONCLUSION

IQ variance in in-treatment individuals with SUD was related to childhood functioning alone or through the mediator of education. Substance-related factors did not contribute to IQ variance. The results fit a normal theory of IQ development with commonly known risk factors and no disturbing effect of substance use.

Loewenstein Occupational Therapy Cognitive Assessment to Evaluate People with Addictions

Background

The LOTCA (Loewenstein Occupational Therapy Cognitive Assessment) battery is a cognitive screening test which is widely used in occupational health. However, no work has been found that explores its use in addiction treatment.

Objectives of Study

To explore the convergent validity of LOTCA with neuropsychological tests that assess related cerebral functional areas.

Methods

The LOTCA, along with a battery of neuropsychological tests, was administered to a sample of 48 subjects who start a treatment by substance or gambling addictions.

Findings

A correlational pattern was observed of a considerable magnitude between the effects of the LOTCA scales and those of some neuropsychological tests, but not with others. There is barely any convergence in measures with memory and executive function tests.

Relevance to Clinical Practice

There is a lack of research applying test of occupational assessment to populations of patients treated by addictive behaviors. The LOTCA seems to be a reliable and valid test for preliminary screening of function in certain cognitive areas, easy, and quick to use (around 30 minutes). However, it must be supplemented with other tests for a full and ecological assessment of patients.

Limitations

An incident, small-size sample.

Recommendations for Further Research

New studies are needed to explore the applicability, diagnostic validity, and whole psychometric quality of the test in addiction-related treatment.

EMDR Interventions in Addiction

The use of tobacco, alcohol, and illicit drugs is widespread and has significant negative consequences for the individual, their families, and the communities to which they belong. A substantial number of users develop an addiction disorder. Cure-oriented addiction treatment is challenging regarding treatment retention and relapse rates. Here, we discuss the potential of eye movement desensitization and reprocessing (EMDR) therapy to aid addiction treatment. Two approaches are distinguished: trauma-focused and addiction-focused EMDR therapy. Existing adapted EMDR protocols and research on both approaches is critically reviewed. Despite 20 years of development and research, the feasibility and efficacy of addiction-focused EMDR therapy is still largely uninvestigated. Exciting new possibilities, offered by research on working memory theory, are discussed. An overview of all resourcing and EMDR therapy interventions in addiction is presented: the palette of EMDR interventions in addiction (PEIA). The article finishes with recommendations for further research in this field.

Examining the interaction between cognitive control and reward sensitivity in substance use dependence

BACKGROUND

Drug dependence is characterized by altered reward processing and poor cognitive control, expressed as a preference for immediate rewards and impaired inhibitory control, respectively. To examine the interaction between reward processing (via the presence or absence of reward) and mechanisms of inhibitory control in drug dependence, the current study used the Monetary Incentive Control Task (MICT) to examine whether a group of opiate dependent persons demonstrated greater difficulty exerting control over immediate rewards compared to neutral stimuli.

METHODS

The MICT is a Go/Stop paradigm that examines inhibitory control over immediate rewards. Performance of 32 opiate dependent individuals was compared to 29 healthy controls.

RESULTS

Opiate users demonstrated poorer inhibitory performance than controls, irrespective of cues signaling immediate reward. Whereas control participants' responses were modulated by probability cues, the opiate group did not show a capacity to up-regulate their cognitive control performance.

CONCLUSIONS

The present results suggest a general decrease in cognitive control in opiate dependence, accompanied by a reduced ability to optimally modulate behavior in accordance with external cues. Opiate users and controls did not differ in the interaction between cognitive control and reward. The study highlights important issues for future research to consider when further examining this interaction in drug dependence.

Ecological momentary assessment of working memory under conditions of simultaneous marijuana and tobacco use

BACKGROUND AND AIMS

The neuropsychological correlates of simultaneous marijuana and tobacco use are largely unknown, which is surprising as both substances have similar neural substrates and have opposing influences on working memory (WM). This study examined the effects of marijuana alone, tobacco alone and simultaneous marijuana and tobacco use on WM.

DESIGN

Primary aims were tested using a within-subject design, controlling for multiple subject- and momentary-level confounds via ecological momentary assessment (EMA).

SETTING

Data collection occurred in the Chicago, USA area in participants' natural environments.

PARTICIPANTS

Participants were 287 community young adults from a larger natural history study, oversampled for ever smoking, all of whom event-recorded at least one substance use occasion during the study week.

MEASUREMENTS

Momentary tobacco, marijuana and alcohol use were recorded during multiple EMA across 1 week of data capture. WM was assessed at the end of each EMA assessment. Contextual variables that may influence WM were recorded via EMA.

FINDINGS

There were main effects for marijuana and tobacco: WM was poorer with marijuana [odds ratio (OR) = 0.91, 95% confidence interval (CI) = 0.84-0.99] and better with tobacco (OR = 1.11, 95% CI = 1.04-1.18). These effects were not qualified by an interaction (OR = 1.03, 95% CI = 0.84-1.26). Alcohol also reduced WM (OR = 0.87, 95% CI = 0.79-0.95), and the tobacco × alcohol interaction was significant (OR = 0.81, 95% CI = 0.66-0.99), indicating that the facilitative effect of tobacco disappeared with concurrent alcohol use.

CONCLUSIONS

Relative to when individuals did not use these substances, working memory decreased with acute marijuana and alcohol use and increased with acute tobacco use. However, the putative effect of marijuana on working memory and the facilitative effect of tobacco on working memory were no longer present when used simultaneously with tobacco and alcohol, respectively. Data suggest that tobacco use may compensate for working memory decrements from marijuana among young adults and highlight the importance of investigating further the negative impact of alcohol use on cognition.

The Role of Cannabinoids in Neuroanatomic Alterations in Cannabis Users

The past few decades have seen a marked change in the composition of commonly smoked cannabis. These changes primarily involve an increase of the psychoactive compound ∆(9)-tetrahydrocannabinol (THC) and a decrease of the potentially therapeutic compound cannabidiol (CBD). This altered composition of cannabis may be linked to persistent neuroanatomic alterations typically seen in regular cannabis users. In this review, we summarize recent findings from human structural neuroimaging investigations. We examine whether neuroanatomic alterations are 1) consistently observed in samples of regular cannabis users, particularly in cannabinoid receptor-high areas, which are vulnerable to the effects of high circulating levels of THC, and 2) associated either with greater levels of cannabis use (e.g., higher dosage, longer duration, and earlier age of onset) or with distinct cannabinoid compounds (i.e., THC and CBD). Across the 31 studies selected for inclusion in this review, neuroanatomic alterations emerged across regions that are high in cannabinoid receptors (i.e., hippocampus, prefrontal cortex, amygdala, cerebellum). Greater dose and earlier age of onset were associated with these alterations. Preliminary evidence shows that THC exacerbates, whereas CBD protects from, such harmful effects. Methodologic differences in the quantification of levels of cannabis use prevent accurate assessment of cannabis exposure and direct comparison of findings across studies. Consequently, the field lacks large "consortium-style" data sets that can be used to develop reliable neurobiological models of cannabis-related harm, recovery, and protection. To move the field forward, we encourage a coordinated approach and suggest the urgent development of consensus-based guidelines to accurately and comprehensively quantify cannabis use and exposure in human studies.

Adolescent Life History Strategy in the Intergenerational Transmission and Developmental Stability of Substance Use

Research suggests that fast life history strategy (LHS) may be a primary driver of substance use among young adults. However, a recent study reported that (a) young adult fast LHS did not subsume all theorized indicators of LHS during this period and (b) fast LHS among parents did not predict young adult fast LHS or liability for use of common substances. In this study, we used structural equations and national data to test whether these findings generalized to adolescence. In addition, given that LHS and substance use share genetic and neuropsychological bases, we examined whether fast LHS could explain the developmental stability of substance use. Overall, our results extend the findings discussed above and suggest that fast LHS fully explains the developmental stability of substance use among youth. We discuss implications for life history models, research applying life history theory and substance use, and substance abuse prevention and treatment.

Emotion regulation in heavy smokers: experiential, expressive and physiological consequences of cognitive reappraisal

Emotion regulation dysfunctions are assumed to contribute to the development of tobacco addiction and relapses among smokers attempting to quit. To further examine this hypothesis, the present study compared heavy smokers with non-smokers (NS) in a reappraisal task. Specifically, we investigated whether non-deprived smokers (NDS) and deprived smokers (DS) differ from non-smokers in cognitive emotion regulation and whether there is an association between the outcome of emotion regulation and the cigarette craving. Sixty-five participants (23 non-smokers, 22 NDS, and 20 DS) were instructed to down-regulate emotions by reappraising negative or positive pictorial scenarios. Self-ratings of valence, arousal, and cigarette craving as well as facial electromyography and electroencephalograph activities were measured. Ratings, facial electromyography, and electroencephalograph data indicated that both NDS and DS performed comparably to nonsmokers in regulating emotional responses via reappraisal, irrespective of the valence of pictorial stimuli. Interestingly, changes in cigarette craving were positively associated with regulation of emotional arousal irrespective of emotional valence. These results suggest that heavy smokers are capable to regulate emotion via deliberate reappraisal and smokers’ cigarette craving is associated with emotional arousal rather than emotional valence. This study provides preliminary support for the therapeutic use of reappraisal to replace maladaptive emotion-regulation strategies in nicotine addicts.

Bayesian neural adjustment of inhibitory control predicts emergence of problem stimulant use

Bayesian ideal observer models quantify individuals' context- and experience-dependent beliefs and expectations about their environment, which provides a powerful approach (i) to link basic behavioural mechanisms to neural processing; and (ii) to generate clinical predictors for patient populations. Here, we focus on (ii) and determine whether individual differences in the neural representation of the need to stop in an inhibitory task can predict the development of problem use (i.e. abuse or dependence) in individuals experimenting with stimulants. One hundred and fifty-seven non-dependent occasional stimulant users, aged 18-24, completed a stop-signal task while undergoing functional magnetic resonance imaging. These individuals were prospectively followed for 3 years and evaluated for stimulant use and abuse/dependence symptoms. At follow-up, 38 occasional stimulant users met criteria for a stimulant use disorder (problem stimulant users), while 50 had discontinued use (desisted stimulant users). We found that those individuals who showed greater neural responses associated with Bayesian prediction errors, i.e. the difference between actual and expected need to stop on a given trial, in right medial prefrontal cortex/anterior cingulate cortex, caudate, anterior insula, and thalamus were more likely to exhibit problem use 3 years later. Importantly, these computationally based neural predictors outperformed clinical measures and non-model based neural variables in predicting clinical status. In conclusion, young adults who show exaggerated brain processing underlying whether to 'stop' or to 'go' are more likely to develop stimulant abuse. Thus, Bayesian cognitive models provide both a computational explanation and potential predictive biomarkers of belief processing deficits in individuals at risk for stimulant addiction.

Chronic cannabis use and ERP correlates of visual selective attention during the performance of a flanker go/nogo task

The aim of the study was to investigate the relationship between chronic cannabis use and visual selective attention by examining event-related potentials (ERPs) during the performance of a flanker go/nogo task. Male participants were 15 chronic cannabis users (minimum two years use, at least once per week) and 15 drug naive controls. Cannabis users showed longer reaction times compared to controls with equivalent accuracy. Cannabis users also showed a reduction in the N2 'nogo effect' at frontal sites, particularly for incongruent stimuli, and particularly in the right hemisphere. This suggests differences between chronic cannabis users and controls in terms of inhibitory processing within the executive control network, and may implicate the right inferior frontal cortex. There was also preliminary evidence for differences in early selective attention, with controls but not cannabis users showing modulation of N1 amplitude by flanker congruency. Further investigation is required to examine the potential reversibility of these residual effects after long-term abstinence and to examine the role of early selective attention mechanisms in more detail.

Topiramate impairs cognitive function in methadone-maintained individuals with concurrent cocaine dependence

Topiramate is being investigated as a potential pharmacotherapy for the treatment of addictive disorders. However, its cognitive side effects raise concerns about its use, especially in populations with cognitive impairment, such as persons with chronic substance use disorders. This study investigated topiramate's cognitive effects in individuals dually dependent on cocaine and opioids as part of a double-blind, randomized, controlled trial of topiramate for cocaine dependence treatment. After 5 weeks of stabilization on daily oral methadone (M = 96 mg), participants were randomized to topiramate (n = 18) or placebo (n = 22). Cognitive testing took place at 2 time points: study weeks 4 through 5 to assess baseline performance and 10 to 13 weeks later to assess performance during stable dosing (300 mg topiramate or placebo). All participants were maintained on methadone at both testing times, and testing occurred 2 hours after the daily methadone plus topiramate/placebo administration. The topiramate and placebo groups did not differ on sex, level of education, premorbid intelligence, methadone dose, or illicit drug use. Topiramate slowed psychomotor and information processing speed, worsened divided attention, reduced n-back working memory accuracy, and increased the false alarm rate in recognition memory. Topiramate had no effects on visual processing, other measures of psychomotor function, risk-taking, self-control, Sternberg working memory, free recall, and metamemory. These findings indicate that topiramate may cause cognitive impairment in this population. This effect may limit its acceptability and use as a treatment in individuals with chronic opioid and cocaine use disorders, among whom preexisting cognitive impairments are common. (PsycINFO Database Record

Life History Strategy and Young Adult Substance Use

This study tested whether life history strategy (LHS) and its intergenerational transmission could explain young adult use of common psychoactive substances. We tested a sequential structural equation model using data from the National Longitudinal Survey of Youth. During young adulthood, fast LHS explained 61% of the variance in overall liability for substance use. Faster parent LHS predicted poorer health and lesser alcohol use, greater neuroticism and cigarette smoking, but did not predict fast LHS or overall liability for substance use among young adults. Young adult neuroticism was independent of substance use controlling for fast LHS. The surprising finding of independence between parent and child LHS casts some uncertainty upon the identity of the parent and child LHS variables. Fast LHS may be the primary driver of young adult use of common psychoactive substances. However, it is possible that the young adult fast LHS variable is better defined as young adult mating competition. We discuss our findings in depth, chart out some intriguing new directions for life history research that may clarify the dimensionality of LHS and its mediation of the intergenerational transmission of substance use, and discuss implications for substance abuse prevention and treatment.

Alcohol and Relatively Pure Cannabis Use, but Not Schizotypy, are Associated with Cognitive Attenuations

Elevated schizotypy relates to similar cognitive attenuations as seen in psychosis and cannabis/polydrug use. Also, in schizotypal populations cannabis and polydrug (including licit drug) use are enhanced. These cognitive attenuations may therefore either be a behavioral marker of psychotic (-like) symptoms or the consequence of enhanced drug use in schizotypal populations. To elucidate this, we investigated the link between cognitive attenuation and cannabis use in largely pure cannabis users (35) and non-using controls (48), accounting for the potential additional influence of both schizotypy and licit drug use (alcohol, nicotine). Cognitive attenuations commonly seen in psychosis were associated with cannabis and alcohol use, but not schizotypy. Future studies should therefore consider (i) non-excessive licit substance use (e.g., alcohol) in studies investigating the effect of cannabis use on cognition and (ii) both enhanced illicit and licit substance use in studies investigating cognition in schizotypal populations.

[Life-threatening fentanyl and propofol addiction: interview with a survivor]

Anesthesiologists have a well-known increased risk of substance abuse including the intravenous administration of opioids and propofol. However, katamnestic reports from the point of view of propofol-addicted anesthesiologists themselves are missing which would aid a better understanding of the dynamics and progress of addiction. This article presents an interview with a formerly addicted female anesthesiologist who after long-term abuse with oral tilidine combined with naloxone switched to intravenous administration of fentanyl and later on propofol. Several life-threatening incidents occurred but after some severe setbacks occupational rehabilitation outside the field of anesthesiology was successful following inpatient treatment. This case shows exemplarily in accordance with the current literature that warning signs in addicted physicians are often ignored by colleagues and supervisors and rehabilitation is possible under professional therapy and continuous surveillance. Additionally, this case emphasizes the necessity of controlling the distribution of propofol to reduce the life-threatening professional risk to anesthesiologists.

An FMRI study of the influence of a history of substance abuse on working memory-related brain activation in schizophrenia

There has been little investigation of the effects of past substance abuse (SA) on working memory (WM) impairments in schizophrenia. This study examined the behavioral and neurobiological impact of past SA (6 months or longer abstinence period) on WM in schizophrenia. Thirty-seven schizophrenia patients (17 with past SA and 20 without) and 32 controls (12 with past SA and 20 without) completed two versions of a two-back WM task during fMRI scanning on separate days. Analyses focused on regions whose patterns of activation replicated across both n-back tasks. Schizophrenia patients were significantly less accurate than controls on both n-back tasks. No main effects or interactions with past SA on WM performance were observed. However, several fronto-parietal-thalamic regions showed an interaction between diagnostic group and past SA. These regions were significantly more active in controls with past SA compared to controls without past SA. Schizophrenia patients with or without past SA either showed no significant differences, or patients with past SA showed somewhat less activation compared to patients without past SA during WM. These results suggest robust effects of past SA on WM brain functioning in controls, but less impact of past SA in schizophrenia. This is consistent with previous literature indicating less impaired neurocognition in schizophrenia with SA.