Decision Making and Impulsivity in Young Adult Cannabis Users

Alterations in self-reported sensory gating and interoception in individuals frequently using cannabis

Background: Cannabis use is associated with altered processing of external (exteroceptive) and internal (interoceptive) sensory stimuli. However, little research exists on whether subjective experiences of these processes are altered in people who frequently use cannabis. Altered exteroception may influence externally oriented attention, whereas interoceptive differences have implications for intoxication, craving, and withdrawal states.Objectives: The goal of the current study was to investigate subjective experiences of exteroceptive sensory gating and interoception in people frequently using cannabis. We hypothesized subjective impairments in sensory gating and elevations in affect-related interoceptive awareness; furthermore, such deviations would relate to cannabis use patterns.Methods: This cross-sectional study of community adults 18-40 years old included 72 individuals (50% female) who used cannabis at least twice a week (not intoxicated during study) and 78 individuals who did not use cannabis (60% female). Participants completed the Sensory Gating Inventory and the Multidimensional Assessment of Interoceptive Awareness-2 surveys. People using cannabis completed surveys on cannabis use patterns. Analyses tested group differences and associations with cannabis use.Results: People using cannabis reported impaired sensory gating (d = 0.37-0.44; all p values < 0.05) and elevations of interoceptive awareness related to detection and affect (d = 0.21-0.61; all p values < 0.05). Problematic cannabis use was associated with increased sensory gating impairments (r = 0.37, p < .05). Interoceptive awareness was unrelated to cannabis use variables.Conclusion: These findings extend literature on subjective experiences of sensory processing in people using cannabis. Findings may inform inclusion of external attentional tendencies and internal bodily awareness in assessments of risk and novel treatment approaches.

Sex differences in neuroendocrine, sympathetic nervous system, and affect responses to acute stress in cannabis users

RATIONALE

Cannabis is the most widely used illicit substance in the USA and is often reportedly used for stress reduction. Indeed, cannabinoids modulate signaling of the hypothalamic-pituitary-adrenal axis and sympathetic nervous system. However, the role of biological sex in this interaction between cannabis use and stress is poorly understood, despite sex differences in neurobiological stress responsivity, endocannabinoid signaling, and clinical correlates of cannabis use.

OBJECTIVE

The study aims to examine the role of biological sex in multisystem stress responsivity in cannabis users.

METHODS

Frequent cannabis users (> 3 times/week, n = 48, 52% male) and non-users (n = 41, 49% male) participated in an acute psychosocial stress paradigm. Saliva was collected at eight timepoints and analyzed for hypothalamic-pituitary-adrenal (cortisol) and sympathetic (alpha-amylase) indices of stress responsivity, and basal estradiol. Subjective ratings of negative affect, including distress, were collected at three timepoints.

RESULTS

Cannabis users showed blunted pre-to-post-stress cortisol reactivity. Female cannabis users demonstrated greater blunted cortisol reactivity than their male counterparts. Sex moderated the effect of cannabis use on alpha-amylase responsivity over time, wherein female cannabis users showed flattened alpha-amylase responses across the stressor compared to male cannabis users and both non-user groups. Qualitatively, female cannabis users demonstrated the greatest pre-to-post-stress change in subjective distress. Differences in stress responding were not explained by estradiol or distress intolerance.

CONCLUSIONS

Biological sex impacts multisystem stress responding in cannabis users. Paradoxically, female cannabis users showed the least physiological, but greatest subjective, responses to the stressor. Further research into sex differences in the effects of cannabis use is warranted to better understand mechanisms and clinical implications.

Parameters of EMA Compliance and Self-Reported Reactivity in a Longitudinal Study of Young Adult Cannabis and Tobacco Co-Users

Background

Co-use of cannabis and tobacco has become increasingly popular among young adults. Interactive voice response (IVR) based ecological momentary assessment (EMA) allows for measurement of behavior in or near real-time, but has limitations including non-compliance, missing data, and potential for reactivity (e.g., behavior change) from frequent assessments.

Methods

This study examined tobacco and cannabis use characteristics and factors associated with IVR compliance and self-reported reactivity in 97 young adults who reported cannabis and tobacco co-use at baseline and completed daily IVR surveys of co-use behavior at three random times per day for 28 days.

Results

Overall IVR compliance was 55%, with a modal compliance of 60%. Compliance rates did not differ across morning, midday, and evening surveys, but significantly declined over time. The sample was divided into high frequency responders (>70% calls completed, n=35) and low frequency responders (<70%, calls completed n=62). There were no differences between high and low frequency responders on any baseline demographic, tobacco use (nicotine dependence severity), alcohol, or cannabis use characteristics (past 30-day frequency of use). Participants were receptive to IVR-based EMA monitoring and, 16.5% reported purposely decreasing nicotine/tobacco use due to monitoring, while 19.6% reported purposely decreasing cannabis use, which predicted lower cannabis use post-EMA monitoring.

Conclusions

Real-time assessment of co-use behavior among young adults does not appear to be impacted by specific demographics or substance use severity (nicotine dependence, heavy drinking). Data suggest some predictive utility of IVR-based EMA monitoring on short-term behavior change. More intensive approaches are needed to improve compliance among young adult cannabis and tobacco co-users.

Time and risk preferences and the perceived effectiveness of incentives to comply with diabetic retinopathy screening among older adults with type 2 diabetes

Behavioral economics has the potential to inform the design of incentives to improve disease screening programs by accounting for various behavioral biases. We investigate the association between multiple behavioral economics concepts and the perceived effectiveness of incentive strategies for behavioral change among older patients with a chronic disease. This association is examined by focusing on diabetic retinopathy screening, which is recommended but very variably followed by persons living with diabetes. Five time and risk preference concepts (i.e., utility curvature, probability weighting, loss aversion, discount rate, and present-bias) are estimated simultaneously in a structural econometric framework, based on a series of deliberately-designed economic experiments offering real money. We find that higher discount rates and loss aversion and lower probability weighting are significantly associated with lower perceived effectiveness of intervention strategies whereas present-bias and utility curvature have an insignificant association with it. Finally, we also observe strong urban vs. rural heterogeneity in the association between our behavioral economic concepts and the perceived effectiveness of intervention strategies.

Long-Term Outcomes of Adolescent THC Exposure on Translational Cognitive Measures in Adulthood in an Animal Model and Computational Assessment of Human Data

Importance

Although perceived as relatively harmless and nonaddictive, adolescent cannabis use significantly increases the likelihood of developing cannabis use disorder in adulthood, especially for high-potency cannabis. Risky decision-making is associated with chronic cannabis use, but given confounds of human studies, it remains unclear whether adolescent cannabis exposure and Δ9-tetrahydrocannabinol (THC) potency specifically predicts risky decision-making or influences cognitive response to the drug later in life.

Objective

To leverage a human data set of cannabis users and a rat model to evaluate the long-term outcomes of adolescent THC exposure on adult decision-making and impulse control.

Design, Setting, and Participants

This translational rat study tested the link between adolescent THC exposure and adulthood decision-making. A reanalysis of a previously published dataset of human chronic cannabis users was conducted to evaluate decision-making phenotypes. Computational modeling assessed the human and animal results in a single framework. Data were collected from 2017 to 2020 and analyzed from 2020 to 2022.

Main Outcomes and Measures

Decision-making was measured by the Iowa Gambling Task (IGT) and Rat Gambling Task (rGT). Impulse control was assessed in the rat model. Computational modeling was used to determine reward and punishment learning rates and learning strategy used by cannabis users and THC-exposed rats. Cell-specific molecular measures were conducted in the prefrontal cortex and amygdala.

Results

Of 37 participants, 24 (65%) were male, and the mean (SD) age was 33.0 (8.3) years. Chronic cannabis users (n = 22; mean [SE] IGT score, -5.182 [1.262]) showed disadvantageous decision-making compared with controls (n = 15; mean [SE] IGT score, 7.133 [2.687]; Cohen d = 1.436). Risky choice was associated with increased reward learning (mean [SE] IGT score: cannabis user, 0.170 [0.018]; control, 0.046 [0.008]; Cohen d = 1.895) and a strategy favoring exploration vs long-term gains (mean [SE] IGT score: cannabis user, 0.088 [0.012]; control, 0.020 [0.002]; Cohen d = 2.218). Rats exposed to high-dose THC but not low-dose THC during adolescence also showed increased risky decision-making (mean [SE] rGT score: vehicle, 46.17 [7.02]; low-dose THC, 69.45 [6.01]; high-dose THC, 21.97 [11.98]; Cohen d = 0.433) and elevated reward learning rates (mean [SE] rGT score: vehicle, 0.17 [0.01]; low-dose THC, 0.10 [0.01]; high-dose THC, 0.24 [0.06]; Cohen d = 1.541) during task acquisition. These animals were also uniquely susceptible to increased cognitive impairments after reexposure to THC in adulthood, which was correlated with even greater reward learning (r = -0.525; P < .001) and a shift in strategy (r = 0.502; P < .001), similar to results seen in human cannabis users. Molecular studies revealed that adolescent THC dose differentially affected cannabinoid-1 receptor messenger RNA expression in the prelimbic cortex and basolateral amygdala in a layer- and cell-specific manner. Further, astrocyte glial fibrillary acidic protein messenger RNA expression associated with cognitive deficits apparent with adult THC reexposure.

Conclusions and Relevance

In this translational study, high-dose adolescent THC exposure was associated with cognitive vulnerability in adulthood, especially with THC re-exposure. These data also suggest a link between astrocytes and cognition that altogether provides important insights regarding the neurobiological genesis of risky cannabis use that may help promote prevention and treatment efforts.

Adolescent self-administration of the synthetic cannabinoid receptor agonist JWH-018 induces neurobiological and behavioral alterations in adult male mice

RATIONALE

The use of synthetic cannabinoid receptor agonists (SCRAs) is growing among adolescents, posing major medical and psychiatric risks. JWH-018 represents the reference compound of SCRA-containing products.

OBJECTIVES

This study was performed to evaluate the enduring consequences of adolescent voluntary consumption of JWH-018.

METHODS

The reinforcing properties of JWH-018 were characterized in male CD1 adolescent mice by intravenous self-administration (IVSA). Afterwards, behavioral, neurochemical, and molecular evaluations were performed at adulthood.

RESULTS

Adolescent mice acquired operant behavior (lever pressing, Fixed Ratio 1-3; 7.5 µg/kg/inf); this behavior was specifically directed at obtaining JWH-018 since it increased under Progressive Ratio schedule of reinforcement, and was absent in vehicle mice. JWH-018 IVSA was reduced by pretreatment of the CB1-antagonist/inverse agonist AM251. Adolescent exposure to JWH-018 by IVSA increased, at adulthood, both nestlet shredding and marble burying phenotypes, suggesting long-lasting repetitive/compulsive-like behavioral effects. JWH-018 did not affect risk proclivity in the wire-beam bridge task. In adult brains, there was an increase of ionized calcium binding adaptor molecule 1 (IBA-1) positive cells in the caudate-putamen (CPu) and nucleus accumbens (NAc), along with a decrease of glial fibrillary acidic protein (GFAP) immunoreactivity in the CPu. These glial alterations in adult brains were coupled with an increase of the chemokine RANTES and a decrease of the cytokines IL2 and IL13 in the cortex, and an increase of the chemokine MPC1 in the striatum.

CONCLUSIONS

This study suggests for the first time that male mice self-administer the prototypical SCRA JWH-018 during adolescence. The adolescent voluntary consumption of JWH-018 leads to long-lasting behavioral and neurochemical aberrations along with glia-mediated inflammatory responses in adult brains.

Impaired risk avoidance in bipolar disorder and substance use disorders

Comorbid substance use disorders are highly prevalent in bipolar disorder, and research suggests that individuals with the comorbid presentation typically have worse outcomes than individuals with bipolar disorder without this comorbidity. However, psychosocial treatments for the comorbid presentation have not demonstrated effectiveness for both mood and substance use symptom domains, suggesting novel treatments are needed. An alternative path to treatment development is to identify mechanisms that underlie comorbid bipolar disorder and substance use disorders that can subsequently be targeted in treatment. We evaluated neurocognitive markers for impairments in risk avoidance (the tendency to engage in a persistent pattern of problematic behaviors despite negative outcomes resulting from such behaviors) as potential mechanistic variables underlying negative illness outcomes in the comorbid population. Participants with bipolar disorder (n = 45) or comorbid bipolar disorder and substance use disorders (n = 31) in a relatively euthymic mood state completed clinical risk behavior assessments, task-based risk avoidance assessments, and neurocognitive assessments. Results indicated a lack of notable between-group differences in the clinical risk composite score, task-based risk avoidance assessments, and neurocognitive assessments, with the exception of self-reported executive dysfunction which was elevated among the comorbid sample. Collapsing across group, we found that increased discounting of delayed rewards, older age, and an earlier age of (hypo)mania onset predicted an increased clinical risk composite score. These findings underscore the potential importance of delay discounting as a novel mechanistic target for reducing clinical risk behaviors among individuals with bipolar disorder both with and without comorbid substance use disorders.

Examining Risk Factors in the Cannabis–Suicide Link: Considering Trauma and Impulsivity among University Students

Cannabis is a commonly used substance among university students that may have several negative health repercussions, including suicidal ideation (SI) and suicide attempts (SA). The factors that contribute to or help explain this relation remain uncertain. Earlier negative experiences, especially trauma encountered during early life, have been associated with the development of psychopathology upon later stressor encounters. In the current study, we examined the associations between SI and SA with problematic cannabis use among young adults and the role of earlier trauma experiences and trait impulsiveness in understanding this link. Among university students (N = 539), problematic cannabis use was moderately related to lifetime and past-12-months suicidal ideation and attempts. Impulsiveness mediated the relationship between problematic cannabis use and lifetime SI and SA. Moreover, previous life trauma moderated the relationship between problematic cannabis use and SA, such that the association between problematic cannabis use and SA was stronger among those who experienced high levels of trauma. These findings highlight behavioral and environmental factors that could predict suicide ideation and attempts among young cannabis users. Accordingly, trait impulsiveness and early trauma experiences should be considered, alongside problematic cannabis use, in suicide-risk detection and prevention strategies among young adults.

The relationship between cannabis use and taurine: A MRS and metabolomics study

Taurine is an essential amino acid. It has been shown to be neuroprotective including protecting against the neurotoxic effects of glutamate. The goal of the current study was to examine the relationship between CB use and taurine measured in brain using magnetic resonance spectroscopy (MRS), and peripherally from a urine sample. Two experiments are presented. The first is a reanalysis of published data that examined taurine and glutamate in the dorsal anterior cingulate of a CB user group and non-user group using MRS. The second experiment, in a separate CB user group, used metabolomics analysis to measure taurine levels in urine. Because body composition has been associated with the pharmacokinetics of cannabis and taurine levels, a moderation model was examined with body composition included as the covariate. The MRS study found taurine levels were correlated with glutamate in both groups and taurine was correlated with frequency of CB use in the CB user group. The moderation model demonstrated significant effects of CB use and BMI; the interaction was marginally significant with lower BMI individuals showing a positive relationship between CB use and taurine. A similar finding was observed for the urine analysis. Both CB use and weight, as well as the interaction were significant. In this case, individuals with higher weight showed an association between CB use and taurine levels. This study shows the feasibility and potential importance of examining the relationship between taurine and CB use as it may shed light on a mechanism that underlies the neuroprotective effects of CB.

Internet addiction in young adults: The role of impulsivity and codependency

Excessive Internet use has demonstrated comorbidity with other psychological symptoms and psychiatric disorders, as well as impairments in the management of daily life, relationships and emotional stability. Recent findings in the literature have consistently supported the relationship between impulsivity and Internet addiction. The present study hypothesized that, in addition to impulsivity, a further predictor of Internet addiction might be relational co-dependency, which is also associated in the literature with addiction phenomena, but mainly substance addiction. This paper investigates the role and predictive weight of impulsivity and codependency on Internet addiction on a sample of young adult university students (n = 481) by using a hierarchical regression analysis. The participants were administered the UADI-2, the BIS-11 and the SFCDS. In terms of percentage distribution, 38 % of the participants were in the dependency range, while 37.7 % demonstrated Internet abuse behavior. The results confirmed the role of impulsiveness (β = 0.312) and added to the literature by showing the significant role of relational codependency (β = 0.275), gender (β = 0.174) and age (β = 0.196). Thus, male participants were more dependent, more impulsive and more co-dependent, with increasing age in the given range (18-30). The present study shed light to the presence of this issue among young adults and that, as a preventive and restraining measure, there is a need not only for targeted awareness-raising programmes but also for interventions to promote greater emotional control and a more balanced management of personal relationships.