Attentional function and inhibitory control in different substance use disorders

Transdiagnostic factors predicting prescription opioid-use disorder severity: A 12-month prospective study in patients on long-term opioid therapy for chronic pain

BACKGROUND

Research has suggested that transdiagnostic factors related to reward, cognitive, and regulatory processes are involved in addictive behaviors and the experience of pain. However, studies of Prescription Opioid-Use Disorder (POUD) in a chronic pain population are scarce. This study aimed to analyze the predictive power of anticipatory pleasure experience, obsessive-compulsive behavior, cognitive control, emotion dysregulation, and sleep on POUD severity in chronic pain patients on long-term opioid therapy.

METHODS

A three-wave prospective study was conducted in a sample of 67 patients. Individual interviews were held to collect self-reported data on transdiagnostic factors, POUD, and sociodemographic and clinical variables. Statistical analysis included repeated measures multinomial mixed models, unadjusted and covariate-adjusted.

RESULTS

Rates of moderate-severe POUD significantly increased at 6- and 12-month follow-ups compared to initial assessment. The inability to experience anticipatory pleasure (OR [95 %CI] = 0.93 [0.89-0.98]), emotion dysregulation (OR = 1.06 [1.03-1.10]), and poorer sleep quality (OR = 1.25 [1.07-1.45]) predicted moderate-severe POUD even in the adjusted models (p< 0.05). In contrast, obsessive-compulsive behavior (OR = 1.02 [0.99-1.06]) was no longer significant after adjustment for covariates (p> 0.05). In addition, cognitive control was the only factor that predicted both mild (OR = 0.96 [0.93-0.99]) and moderate-severe (OR = 0.94 [0.90-0.98]) disorder (p< 0.05). Furthermore, when all transdiagnostic factors were included in a single model, cognitive control and anticipatory pleasure experience emerged as the strongest predictors of POUD severity, respectively (p< 0.05).

CONCLUSIONS

The identification of key transdiagnostic factors related to POUD severity allows for a more specific profiling of patients at increased risk, potentially leading to improved treatment targets for chronic pain population on opioid therapy.

Regular cannabis use modulates gamma activity in brain regions serving motor control

BACKGROUND

People who regularly use cannabis exhibit altered brain dynamics during cognitive control tasks, though the impact of regular cannabis use on the neural dynamics serving motor control remains less understood.

AIMS

We sought to investigate how regular cannabis use modulates the neural dynamics serving motor control.

METHODS

Thirty-four people who regularly use cannabis (cannabis+) and 33 nonusers (cannabis-) underwent structured interviews about their substance use history and performed the Eriksen flanker task to map the neural dynamics serving motor control during high-density magnetoencephalography (MEG). The resulting neural data were transformed into the time-frequency domain to examine oscillatory activity and were imaged using a beamforming approach.

RESULTS

MEG sensor-level analyses revealed robust beta (16-24 Hz) and gamma oscillations (66-74 Hz) during motor planning and execution, which were imaged using a beamformer. Both responses peaked in the left primary motor cortex and voxel time series were extracted to evaluate the spontaneous and oscillatory dynamics. Our key findings indicated that the cannabis+ group exhibited weaker spontaneous gamma activity in the left primary motor cortex relative to the cannabis- group, which scaled with cannabis use and behavioral metrics. Interestingly, regular cannabis use was not associated with differences in oscillatory beta and gamma activity, and there were no group differences in spontaneous beta activity.

CONCLUSIONS

Our findings suggest that regular cannabis use is associated with suppressed spontaneous gamma activity in the left primary motor cortex, which scales with the degree of cannabis use disorder symptomatology and is coupled to behavioral task performance.

Gender disparities in neuropsychological assessment research in drug abuse populations: A systematic review

Objective: To systematically review the literature on the neurocognitive effects of drug use to determine if there are significant gender differences. Methods: In April 2023, we conducted a broad search in MEDLINE (via PubMed), PsycINFO, and Embase for original research studies that used objective neuropsychological assessment to evaluate neurocognition in persons with drug use. Data extraction was performed in a masked, duplicate fashion. Results: Our initial search returned 22,430 records, of which 273 articles were included in our analysis. We found significant underrepresentation of women as participants in the studies. Twenty-one percent of studies had exclusively male participants; when women were included, they averaged only 23% of the sample. Only 49 studies sufficiently documented an analysis of their results by gender; due to the heterogeneity in study characteristics, no conclusions about cognitive differences between women and men could be made. Conclusions: Women are significantly underrepresented in the research on cognition in drug use. Increased efforts to include more women participants and consistent analysis and reporting of data for potential gender differences will be required to close this gap in knowledge, which may lead to improved substance abuse treatment approaches for women.

Common and Distinct Drug Cue Reactivity Patterns Associated with Cocaine and Heroin: An fMRI Meta-Analysis

Substance use and substance use disorders represent ongoing major public health crises. Specifically, the use of substances such as cocaine and heroin are responsible for over 50,000 drug related deaths combined annually. We used a comparative meta-analysis procedure to contrast activation patterns associated with cocaine and heroin cue reactivity, which may reflect substance use risk for these substances. PubMed and Google Scholar were searched for studies with within-subject whole brain analyses comparing drug to neutral cues for users of cocaine and heroin published between 1995 and 2022. A total of 18 studies were included, 9 in each subgroup. Voxel-based meta-analyses were performed using seed-based d mapping with permuted subject images (SDM-PSI) for subgroup mean analyses and a contrast meta-regression comparing the two substances. Results from our mean analysis indicated that users of heroin showed more widespread activation in the nucleus accumbens, right inferior and left middle temporal gyrus, right thalamus, and right cerebellum. Cocaine use was associated with recruitment of dorsolateral prefrontal cortex during cue reactivity. Direct comparison of cue reactivity studies in heroin relative to cocaine users revealed greater activation in dopaminergic targets for users of heroin compared to users of cocaine. Differential activation patterns between substances may underlie differences in the clinical characteristics observed in users of cocaine and heroin, including seeking emotional blunting in users of heroin. More consistent research methodology is needed to provide adequate studies for stringent meta-analyses examining common and distinct neural activation patterns across substances and moderation by clinically relevant factors.