Working memory predicts methamphetamine hair concentration over the course of treatment: moderating effect of impulsivity and implications for dual-systems model

Major Depressive Disorder as a Driver of Dual Systems Model Development During Adolescence and Emerging Adulthood Among Justice-Involved Youth: Is Salience Age-Graded?

The dual systems model is a psychological framework centered on differential development of sensation-seeking and impulse control during adolescence and emerging adulthood with implications for understanding antisocial behavior. However, there is a dearth of research which has examined mental illness as a driver of differential development of these constructs. This study examined major depressive disorder as a risk factor for elevated sensation-seeking and diminished impulse control and tested to determine whether the salience differed by age. The Pathways to Desistance data were analyzed. Mixed effects models examined the direct effect of major depressive disorder on dual systems outcomes and test for moderation by age. Findings indicated that major depressive disorder at baseline was associated with increased sensation-seeking and diminished impulse control. Relationships did not differ in salience based on age. Results suggest that treatment effective for addressing depression may have relevance for mitigating the impact of the disorder on cognition.

Perirhinal to prefrontal circuit in methamphetamine induced recognition memory deficits

Return to methamphetamine (meth) use is part of an overarching addictive disorder hallmarked by cognitive sequela and cortical dysfunction in individuals who use meth chronically. In rats, long access meth self-administration produces object recognition memory deficits due to drug-induced plasticity within the perirhinal cortex (PRH). PRH projections are numerous and include the medial prefrontal cortex (mPFC). To evaluate the role of the PRH-mPFC reciprocal circuit in novel object recognition memory, a rgAAV encoding GFP-tagged Cre recombinase was infused into the PRH or the mPFC and rats were tested for recognition memory. On test day, one group explored both familiar and novel objects. A second group explored only familiar objects. GFP and Fos expression were visualized in the mPFC or PRH. During exploration, PRH neurons receiving input from the mPFC were equally activated by exploration of novel and familiar objects. In contrast, PRH neurons that provide input to the mPFC were disproportionately activated by novel objects. Further, the percent of Fos + cells in the PRH positively correlated with recognition memory. As such, the flow of communication appears to be from the PRH to the mPFC. In agreement with this proposed directionality, chemogenetic inhibition of the PRH-mPFC circuit impaired object recognition memory, whereas chemogenetic activation in animals with a history of long access meth self-administration reversed the meth-induced recognition memory deficit. This finding informs future work aimed at understanding the role of the PRH, mPFC, and their connectivity in meth associated memory deficits. These data suggest a more complex circuitry governing recognition memory than previously indicated with anatomical or lesion studies.

Impaired proactive control in individuals with methamphetamine use disorder: Evidence from ERPs

BACKGROUND

Research suggests that methamphetamine use is associated with impaired cognitive control, which may contribute to impulsive drug use. Cognitive control is dynamically mediated by proactive and reactive control (reflecting various processing stages of cognitive control with different properties), and it is crucial to determine whether methamphetamine use impairs proactive and/or reactive control. To address this issue, we conducted an event-related potential (ERP) study to examine proactive and reactive control in individuals with methamphetamine use disorder (MUD).

METHODS

Abstinent individuals with MUD (n = 25) and healthy controls (HC, n = 27) completed a cued task-switching task while brain electrical activity was recorded. Cue- and target-locked ERP components modulated by task switching were linked to proactive and reactive control, respectively.

RESULTS

No behavioral differences between the groups were found. However, the HC group showed cue-locked switch-positivity (i.e., more positive amplitudes for switch than repeat trials) in both the early and late time windows, although the MUD group only showed late switch-positivity, which was smaller than the HC group. Independent of switch or congruent condition, the MUD group had smaller target-locked positivity than the HC group.

CONCLUSIONS

These findings suggest that individuals with MUD exhibit reduced proactive control and mobilize extra reactive control efforts to compensate. Our study contributes to a better understanding of cognitive control impairment in individuals with MUD and has implications for potential interventions.

Proof-of-concept trial of Goal Management Training+ to improve executive functions and treatment outcomes in methamphetamine use disorder

BACKGROUND

Deficits in executive function are common in methamphetamine use disorder (MUD), likely contributing to difficulties in sustained treatment success. Cognitive remediation interventions are designed to treat such deficits but have not been adapted to the needs of people with MUD. This study presents a proof-of-concept trial to evaluate a new cognitive remediation program for MUD, Goal Management Training⁺ (GMT⁺).

METHODS

This was a cluster-randomised crossover trial comparing GMT⁺ with a psychoeducation-based control (Brain Health Workshop; BHW). GMT⁺ is a therapist-administered group-based cognitive remediation for executive dysfunction comprising four 90-minute weekly sessions and daily journal activities. BHW is a lifestyle psychoeducation program matched to GMT⁺ for therapist involvement, format, and duration. Participants (n = 36; GMT n = 17; BHW n = 19) were recruited from therapeutic communities in Victoria, Australia. Primary outcomes included intervention acceptability, feasibility, and improvements in self-reported executive function. Secondary outcomes included cognitive tests of executive function, severity of methamphetamine dependence, craving, and quality of life. We performed mixed linear modelling and calculated Hedges' g effect sizes.

RESULTS

GMT⁺ participant ratings and program retention indicated high acceptability. There was no difference between GMT⁺ and BHW on self-reported executive function (g = 0.06). Cognitive tasks suggested benefits of GMT⁺ on information gathering (g = 0.88) and delay-discounting (g = 0.80). Severity of methamphetamine dependence decreased more in GMT⁺ (g = 1.47).

CONCLUSIONS

GMT⁺ was well-accepted but did not improve self-reported executive functioning. Secondary outcomes suggested GMT⁺ was beneficial for objective cognitive performance and severity of dependence.

The effect of the NLRP1 inflammasome on methamphetamine-induced cognitive impairment in rats

Methamphetamine (METH) use disorder has been shown to be in high comorbidity with cognitive deficits. METH-induced cognitive deficits are accompanied by neurotoxicity which could result from neuroinflammation. The potential role of NLRP1 inflammasome (NLRP1) and the downstream signalling pathway in METH-induced cognitive impairment was explored in the current study. Cognitive functions and the changes of NLRP1/Caspase-1/GSDMD signalling pathway were firstly determined in rats receiving daily injections of METH. Subsequently, the effects of aspirin-triggered-lipoxin A4 (ATL), a potent anti-inflammatory mediator, and NLRP1 siRNA was investigated were investigated in both METH-treated rats and HT22 cells. METH induces significant cognitive deficits in rats, using the NOR test. METH-induced cognitive impairment was in line with increased activities of NLRP1, cleaved-Caspase-11, IL-1β and TNF-α and the presence of GSDMD-mediated pyroptosis in the hippocampus of rats. NLRP1 inhibition by ATL significantly attenuated METH-induced cognitive impairment, in conjunction with the decreased activities of NLRP1 and cleaved-Caspase-1, IL-1β and TNF-α. ATL and NLRP1 siRNA also prevented the presence of apoptosis in the hippocampus of METH-treated rats and the cell death in METH-treated HT22 cells. These results reveal a novel role of NLRP1 and the downstream signaling pathways in the complex actions of METH-induced cognitive deficits.

Computational models of exploration and exploitation characterise onset and efficacy of treatment in methamphetamine use disorder

People with Methamphetamine Use Disorder (PwMUD) spend substantial time and resources on substance use, which hinders their ability to explore alternate reinforcers. Gold‐standard behavioural treatments attempt to remedy this by encouraging action towards non‐drug reinforcers, but substance use often persists. We aimed to unravel the mechanistic drivers of this behaviour by applying a computational model of explore/exploit behaviour to decision‐making data (Iowa Gambling Task) from 106 PwMUD and 48 controls. We then examined the longitudinal link between explore/exploit mechanisms and changes in methamphetamine use 6 weeks later. Exploitation parameters included reinforcement sensitivity and inverse decay (i.e., number of past outcomes used to guide choices). Exploration parameters included maximum directed exploration value (i.e., value of trying novel actions). The Timeline Follow Back measured changes in methamphetamine use. Compared to controls, PwMUD showed deficits in exploitative decision‐making, characterised by reduced reinforcement sensitivity, U = 3065, p = 0.009, and less use of previous choice outcomes, U = 3062, p = 0.010. This was accompanied by a behavioural pattern of frequent shifting between choices, which appeared consistent with random exploration. Furthermore, PwMUD with greater reductions of methamphetamine use at 6 weeks had increased directed exploration (β = 0.22, p = 0.045); greater use of past choice outcomes (β = −0.39, p = 0.002) and greater choice consistency (β = −0.39, p = 0.002). Therefore, limited computational exploitation and increased behavioural exploration characterise PwMUD's presentation to treatment, while increased directed exploration, use of past choice outcomes and choice consistency predict greater reductions of methamphetamine use.

Relevance of the dual systems model for predicting drug/alcohol dependence in early adulthood among previously adjudicated young adults

BACKGROUND

While the dual system model has been found to have utility for predicting drug use, examinations have yet to extend to the clinically relevant issue of drug/alcohol dependence. This study sought to provide better understanding of how the dual systems model constructs (impulse control and sensation-seeking) predicted risk for drug/alcohol dependence in early adulthood among a sample of young adults who were adjudicated for a serious offense as minors.

METHODS

Data from several waves of the Pathways to Desistance data were used in analyses. Logistic regression was used to model covariate effects on drug/alcohol dependence risk.

RESULTS

Findings indicated that lower impulse control predicted increased odds of meeting criteria for drug/alcohol dependence in early adulthood. Sensation-seeking was not a significant predictor of drug/alcohol dependence risk at follow-up.

CONCLUSIONS

Lower impulse control was predictive of drug/alcohol dependence risk. Prevention programming should seek to boost impulse control during adolescence to mitigate this risk and treatment programming should focus on impulse control training in order to treat drug/alcohol dependence in inpatient and outpatient contexts.

Bidirectional causality between addiction and cognitive deficits

Cognitive deficits are highly comorbid with substance use disorders. Deficits span multiple cognitive domains, are associated with disease severity across substance classes, and persist long after cessation of substance use. Furthermore, recovery of cognitive function during protracted abstinence is highly predictive of treatment adherence, relapse, and overall substance use disorder prognosis, suggesting that addiction may be best characterized as a disease of executive dysfunction. While the association between cognitive deficits and substance use disorders is clear, determining causalities is made difficult by the complex interplay between these variables. Cognitive dysfunction present prior to first drug use can act as a risk factor for substance use initiation, likelihood of pathology, and disease trajectory. At the same time, substance use can directly cause cognitive impairments even in individuals without preexisting deficits. Thus, parsing preexisting risk factors from substance-induced adaptations, and how they may interact, poses significant challenges. Here, focusing on psychostimulants and alcohol, we review evidence from clinical literature implicating cognitive deficits as a risk factor for addiction, a consequence of substance use, and the role the prefrontal cortex plays in these phenomena. We then review corresponding preclinical literature, highlighting the high degree of congruency between animal and human studies, and emphasize the unique opportunity that animal models provide to test causality between cognitive phenotypes and substance use, and to investigate the underlying neurobiology at a cellular and molecular level. Together, we provide an accessible resource for assessing the validity and utility of forward- and reverse-translation between these clinical and preclinical literatures.

Dysfunctional personality beliefs and emotion recognition in individuals with methamphetamine dependence

Previous studies have demonstrated that individuals with methamphetamine dependence have impaired emotion recognition. However, heterogeneity in results from these studies may indicate that individual factors such as personality beliefs moderate emotion recognition deficits. Thus, we aimed to examine the relationship between dimensional estimates of dysfunctional personality beliefs and facial emotion recognition in 86 Australian treatment seekers with methamphetamine dependence. Dysfunctional beliefs were measured using the Personality Beliefs Questionnaire, and emotion recognition was measured with the Ekman's Faces Test. We applied hierarchical regression analyses to test the relationship between beliefs and emotion recognition after accounting for the effects of intelligence. Results indicated that personality beliefs reflecting antisocial and paranoid schemas together accounted for a significant increase in the variance in fear recognition (higher levels of beliefs associated with poorer fear recognition). Further, high levels of passive-aggressive personality beliefs were associated with a tendency to misclassify faces as disgust. Our findings suggest that antisocial, paranoid, and passive-aggressive dysfunctional personality beliefs may underlie inter-individual differences in emotion recognition in methamphetamine dependent individuals. Additional research is required to better understand the relationship between personality and social processing biases, and investigate the direct impact these have on the significant psychosocial impairments present in individuals with methamphetamine dependence.

A Roadmap for Integrating Neuroscience Into Addiction Treatment: A Consensus of the Neuroscience Interest Group of the International Society of Addiction Medicine

Although there is general consensus that altered brain structure and function underpins addictive disorders, clinicians working in addiction treatment rarely incorporate neuroscience-informed approaches into their practice. We recently launched the Neuroscience Interest Group within the International Society of Addiction Medicine (ISAM-NIG) to promote initiatives to bridge this gap. This article summarizes the ISAM-NIG key priorities and strategies to achieve implementation of addiction neuroscience knowledge and tools for the assessment and treatment of substance use disorders. We cover two assessment areas: cognitive assessment and neuroimaging, and two interventional areas: cognitive training/remediation and neuromodulation, where we identify key challenges and proposed solutions. We reason that incorporating cognitive assessment into clinical settings requires the identification of constructs that predict meaningful clinical outcomes. Other requirements are the development of measures that are easily-administered, reliable, and ecologically-valid. Translation of neuroimaging techniques requires the development of diagnostic and prognostic biomarkers and testing the cost-effectiveness of these biomarkers in individualized prediction algorithms for relapse prevention and treatment selection. Integration of cognitive assessments with neuroimaging can provide multilevel targets including neural, cognitive, and behavioral outcomes for neuroscience-informed interventions. Application of neuroscience-informed interventions including cognitive training/remediation and neuromodulation requires clear pathways to design treatments based on multilevel targets, additional evidence from randomized trials and subsequent clinical implementation, including evaluation of cost-effectiveness. We propose to address these challenges by promoting international collaboration between researchers and clinicians, developing harmonized protocols and data management systems, and prioritizing multi-site research that focuses on improving clinical outcomes.

A Newly Designed Mobile-Based Computerized Cognitive Addiction Therapy App for the Improvement of Cognition Impairments and Risk Decision Making in Methamphetamine Use Disorder: Randomized Controlled Trial

Background

Cognitive rehabilitation therapy has been found to improve cognitive deficits and impulse control problems in methamphetamine use disorder (MUD). However, there is limited research regarding this therapy’s feasibility when using mobile-based health technologies in supporting recovery from MUD in China.

Objective

The main aim of this study was to test whether 4 weeks of a newly designed computerized cognitive addiction therapy (CCAT) app can improve cognitive impairments, eliminate drug-related attention bias, and attenuate risk decision-making behaviors in participants with MUD.

Methods

Forty MUD participants were assigned randomly to either the CCAT group (n=20), who received 4 weeks of CCAT plus regular detoxification treatment as usual, or the control group (n=20), who only received the regular detoxification treatment as usual, in drug rehabilitation centers in Shanghai. The CCAT was designed by combine methamphetamine use-related picture stimuli with cognitive training with the aim of improving cognitive function and eliminating drug-related attention bias. The CogState Battery, Delay Discounting Task (DDT), Iowa Gambling Task (IGT), and Balloon Analog Risk Task (BART) were administered face-to-face to all participants before and after CCAT interventions.

Results

Forty male patients were recruited. The mean age was 32.70 (SD 5.27) years in the CCAT group and mean 35.05 (SD 8.02) years in the control group. Compared to the control group, CCAT improved working memory in the CCAT group (P=.01). Group×time interactions were observed among DDT, IGT, and BART tasks, with rates of discounting delayed rewards, IGT, and BART scores (P<.001) being reduced among those who received CCAT, whereas no changes were found in the control group.

Conclusions

The newly designed CCAT can help to improve cognitive impairment and impulsive control in MUD. Further study is needed to understand the underlying brain mechanisms of the cognitive therapy.

Trial Registration

ClinicalTrials.gov NCT03318081; https://clinicaltrials.gov/ct2/show/NCT03318081 (Archived by WebCite at https://clinicaltrials.gov/ct2/show/NCT03318081)