Triple network resting-state functional connectivity patterns of alcohol heavy drinking.

AIMS: Previous neuroimaging research in alcohol use disorder (AUD) has found altered functional connectivity in the brain's salience, default mode, and central executive (CEN) networks (i.e. the triple network model), though their specific associations with AUD severity and heavy drinking remains unclear. This study utilized resting-state fMRI to examine functional connectivity in these networks and measures of alcohol misuse. METHODS: Seventy-six adult heavy drinkers completed a 7-min resting-state functional MRI scan during visual fixation. Linear regression models tested if connectivity in the three target networks was associated with past 12-month AUD symptoms and number of heavy drinking days in the past 30 days. Exploratory analyses examined correlations between connectivity clusters and impulsivity and psychopathology measures. RESULTS: Functional connectivity within the CEN network (right and left lateral prefrontal cortex [LPFC] seeds co-activating with 13 and 15 clusters, respectively) was significantly associated with AUD symptoms (right LPFC: ß = .337, p-FDR = .016; left LPFC: ß = .291, p-FDR = .028) but not heavy drinking (p-FDR > .749). Post-hoc tests revealed six clusters co-activating with the CEN network were associated with AUD symptoms-right middle frontal gyrus, right inferior parietal gyrus, left middle temporal gyrus, and left and right cerebellum. Neither the default mode nor the salience network was significantly associated with alcohol variables. Connectivity in the left LPFC was correlated with monetary delay discounting (r = .25, p = .03). CONCLUSIONS: These findings support previous associations between connectivity within the CEN network and AUD severity, providing additional specificity to the relevance of the triple network model to AUD.

Identifying Substitute Activities for Alcohol Consumption: A Preliminary Analysis.

Individuals with alcohol use disorder may excessively value alcohol reinforcement over other types of rewards and may seek out environments supportive of alcohol consumption despite negative consequences. Therefore, examining ways to increase engagement in substance-free activities may be useful in treating alcohol use disorder. Past research has focused on preference and frequency of engagement in alcohol-related versus alcohol-free activities. However, no study to-date has examine the incompatibility of such activities with alcohol consumption, an important step in preventing possible adverse consequences during treatment for alcohol use disorder and for ensuring that activities do not function in a complementary fashion with alcohol consumption. The present study was a preliminary analysis comparing a modified activity reinforcement survey with the inclusion of a suitability question to determine the incompatibility of common survey activities with alcohol consumption. Participants recruited from Amazon's Mechanical Turk (N=146) were administered an established activity reinforcement survey, questions regarding the incompatibility of the activities with alcohol consumption, and measures of alcohol-related problems. We found that activity surveys may identify activities that are enjoyable without alcohol, but that some of these activities were still compatible with alcohol. For many of the activities examined, participants who rated those activities as suitable with alcohol also reported higher alcohol severity, with the largest effect size differences for physical activity, school or work, and religious activities. The results of this study are an important preliminary analysis for determining how activities may function as substitutes, and may hold implications for harm reduction interventions and public policy.

Neuroanatomical foundations of delayed reward discounting decision making II: Evaluation of sulcal morphology and fractal dimensionality.

Delayed reward discounting (DRD) is a form of decision-making reflecting valuation of smaller immediate rewards versus larger delayed rewards, and high DRD has been linked to several health behaviors, including substance use disorders, attention-deficit/hyperactivity disorder, and obesity. Elucidating the underlying neuroanatomical factors may offer important insights into the etiology of these conditions. We used structural MRI scans of 1038 Human Connectome Project participants (Mage = 28.86, 54.7% female) to explore two novel measures of neuroanatomy related to DRD: 1) sulcal morphology (SM; depth and width) and 2) fractal dimensionality (FD), or cortical morphometric complexity, of parcellated cortical and subcortical regions. To ascertain unique contributions to DRD preferences, indicators that displayed significant partial correlations with DRD after family-wise error correction were entered into iterative mixed-effect models guided by the association magnitude. When considering only SM indicators, the depth of the right inferior and width of the left central sulci were uniquely associated with DRD preferences. When considering only FD indicators, the FD of the left middle temporal gyrus, right lateral orbitofrontal cortex, and left lateral occipital and entorhinal cortices uniquely contributed DRD. When considering SM and FD indicators simultaneously, the right inferior frontal sulcus depth and left central sulcus width; and the FD of the left middle temporal gyrus, lateral occipital cortex and entorhinal cortex were uniquely associated with DRD. These results implicate SM and FD as features of the brain that underlie variation in the DRD decision-making phenotype and as promising candidates for understanding DRD as a biobehavioral disease process.

Dissociative symptomatology mediates the relation between posttraumatic stress disorder severity and alcohol-related problems.

BACKGROUND: Up to 50% of individuals with posttraumatic stress disorder (PTSD) endorse problematic alcohol use. Typically, these individuals present with more complex and often more severe PTSD symptoms than those who do not report problematic alcohol use. Emerging literature suggests that heightened symptoms of dissociation are likewise associated with greater PTSD symptom severity. Despite this knowledge, the role of dissociation in the relation between PTSD severity and alcohol-related problems has yet to be examined. Here, we explore the mediating role of dissociative symptomatology on the association between PTSD severity and alcohol-related problems within a PTSD treatment-seeking sample. METHODS: Structural equation modeling was used to test the mediating role of dissociative symptomatology between PTSD severity and alcohol-related problems. Participants [N = 334; mean age (SD) = 44.29 (9.77), 50% female] were drawn from a clinical intake battery database for PTSD in-patient treatment services at Homewood Health Care, Guelph, ON, Canada. A subset of battery measures assessing PTSD severity, dissociative symptomatology, and alcohol-related problems were submitted to analysis. RESULTS: A significant positive association emerged between PTSD severity and alcohol-related problems (ß = 0.127, p < 0.05) in the absence of dissociative symptomatology. Critically, however, when added to this model, dissociative symptomatology (six unique facets of dissociation assessed by the Multiscale Dissociation Inventory) mediated the relation between PTSD severity and alcohol-related problems. Specifically, greater PTSD severity was associated with greater dissociative symptomatology (ß = 0.566, p < 0.0001), which was in turn associated with greater alcohol-related problems (ß = 0.184, p < 0.05). CONCLUSIONS: These results suggest that dissociative symptomatology plays a key role in explaining the relation between PTSD severity and alcohol-related problems. Future studies should examine the impact of targeting dissociative symptomatology specifically in treating individuals with PTSD who endorse alcohol-related problems.

Pathologies of precision: A Bayesian account of goals, habits, and episodic foresight in addiction.

The brain is thought to implement two decision-making systems: a goal-directed system in which decisions are made through planning on the basis of action-outcome relationships, and a habitual system in which behaviour reflects stimulus-response associations. A prominent theory of addiction sees it as arising due to an extreme dominance of habit over goal-directed action. The balance between these systems is thought to be arbitrated by the relative precision of their separate predictions of reward. In this paper, we argue that various factors in addiction create hyper-precise reward predictions in the habitual system and hypo-precise reward predictions in the goal-directed system, shifting the balance of behavioural control in favour of habit. Based on this, we offer a theoretical account of the utility of episodic future thinking in addiction, interpreting it as increasing the precision of reward estimates in the goal-directed system, thereby enhancing the control of this system over behaviour.

Delayed Reward Discounting as a Prognostic Factor for Smoking Cessation Treatment Outcome: A Systematic Review.

INTRODUCTION: While large proportions of smokers attempt to quit, rates of relapse remain high and identification of valid prognostic markers is of high priority. Delayed reward discounting (DRD) is a behavioral economic index of impulsivity that has been associated with smoking cessation, albeit inconsistently. This systematic review sought to synthesize the empirical findings on DRD as a predictor of smoking cessation treatment outcome, to critically appraise the quality of the literature, and to propose directions for future research. AIMS AND METHODS: A total of 734 articles were identified, yielding k = 14 studies that met the eligibility criteria. The Quality in Prognosis Studies (QUIPS) tool was used to assess methodological quality of the included studies. RESULTS: Individual study methods were highly heterogeneous, including substantial variation in research design, DRD task, clinical subpopulation, and treatment format. The predominant finding was that steeper DRD (higher impulsivity) was associated with significantly worse smoking cessation outcomes (10/14 studies). Negative results tended to be in pregnant and adolescent subpopulations. The QUIPS results suggested low risk of bias across studies; 11/14 studies were rated as low risk of bias for 5/6 QUIPS domains. CONCLUSIONS: This review revealed consistent low-bias evidence for impulsive DRD as a negative prognostic predictor of smoking cessation treatment outcome in adults. However, methodological heterogeneity was high, precluding meta-analysis and formal tests of small study bias. The prospects of targeting impulsive DRD as a potentially modifiable risk factor or providing targeted treatment for smokers exhibiting high levels of discounting are discussed. IMPLICATIONS: These findings indicate consistent evidence for DRD as a negative prognostic factor for smoking cessation outcome in adults. As such, DRD may be a useful as a novel treatment target or for identifying high-risk populations requiring more intensive treatment.

Posttraumatic Stress Disorder Symptomatology and Substance Use in an Outpatient Concurrent Disorders Sample.

OBJECTIVE: Posttraumatic stress disorder (PTSD) and substance use disorders (SUDs) present a complex and often severe clinical presentation within a concurrent disorders context. The objective of this study was to examine associations between PTSD symptoms and SUD outcomes to better understand the clinical phenomenon of comorbid PTSD and SUD. Multivariate statistical methods were used to test the hypothesis that elevated PTSD symptoms, both at the level of global severity and specific PTSD symptom clusters, are associated with greater substance use and related problems. METHODS: Data were collected from an intake assessment battery within a specialized concurrent disorders outpatient service in Hamilton, ON. The sample comprised 326 participants (mean age = 37.19, 45.4% female). Structural equation models examined associations between PTSD and alcohol, cannabis, and substance use frequency and problems, controlling for age and sex. Alcohol was ultimately dropped from the model due to non-significant bivariate associations. RESULTS: Higher global PTSD symptomatology was significantly associated with higher cannabis and other substance use frequency and related problems. Analyses using PTSD cluster scores showed higher scores for alterations in arousal were positively associated with cannabis-related problems, drug-related problems, and cannabis and other substance use frequency. Avoidance was significantly associated with cannabis frequency and cannabis-related problems. In general, effect sizes were small in magnitude, accounting for between 9% and 25% of variance. CONCLUSION: Significant cluster-level associations indicate the importance of specific PTSD symptoms (hyperarousal, avoidance) in relation to substance use when identifying therapeutic targets among individuals presenting with comorbid PTSD-SUD. This multivariate approach provides a higher resolution and potentially more clinically informative representation of the complex clinical presentation of PTSD and SUD in a concurrent disorder population and could guide the development of more effective treatment paths.

Latent Profile Analysis of Heavy Episodic Drinking in Emerging Adults: A Reinforcer Pathology Approach.

BACKGROUND: Heavy episodic drinking (HED) is a major public health problem among emerging adults (individuals 18 to 25), but with considerable heterogeneity in concurrent substance use and psychopathology. The current study used latent profile analysis (LPA) to detect discrete subgroups of HED based on alcohol, other drug severity, and concurrent psychopathology. A reinforcer pathology approach was used to understand motivational differences among the latent subgroups. METHODS: Participants were 2 samples of emerging adults reporting regular HED, 1 Canadian (n = 730) and 1 American (n = 602). Indicators for the LPA were validated dimensional self-report assessments of alcohol severity, cannabis severity, other drug severity, nicotine dependence, depression, anxiety, posttraumatic stress disorder, and attention-deficit/hyperactivity disorder. Reinforcer pathology indicators were measures of alcohol demand, proportionate substance-related reinforcement, and discounting of future rewards. RESULTS: The LPA yielded parallel 3-class solutions in both samples. The largest subgroup was characterized by comparatively low substance severity and psychopathology (Low overall severity). The second largest subgroup was characterized by comparatively high alcohol and other drug severity (excluding tobacco) and high levels of psychopathology (Heavy alcohol & high psychiatric severity). The third subgroup exhibited high alcohol, smoking and intermediate levels of other substance use and psychopathology (Heavy alcohol, smoking, & intermediate psychiatric severity). The Heavy alcohol & high psychiatric severity and Heavy alcohol, smoking, & intermediate psychiatric severity subgroups exhibited significantly higher alcohol demand, greater proportionate substance-related reinforcement, and steeper delay discounting. CONCLUSIONS: Parallel latent subgroups of emerging adults engaging in HED were present in both samples, and the high-risk subgroups were significantly differentiated by the reinforcer pathology indicators. These latent profiles may ultimately inform heterogeneity in the longitudinal course of HED in emerging adults.

Cannabis involvement and neuropsychological performance: findings from the Human Connectome Project

Background: There is evidence that heavy cannabis use is associated with decrements in cognitive performance, but findings are mixed and studies are often limited by small sample sizes and narrow adjustment for potential confounding variables. In a comparatively large sample, the current study examined associations between multiple indicators of cannabis use in relation to performance on a variety of neuropsychological tasks. Methods: Participants were 1121 adults (54% female) enrolled in the Human Connectome Project. Cannabis involvement comprised recent cannabis use (positive tetrahydrocannabinol screen), total number of lifetime uses, cannabis use disorder and age at first use. The neuropsychological battery comprised performance in episodic memory, fluid intelligence, attention, working memory, executive function, impulsive decision-making, processing speed and psychomotor dexterity. Covariates were age, sex, income, family structure and alcohol and tobacco use. Results: Positive urinary tetrahydrocannabinol status was associated with worse performance in episodic memory and processing speed, and positive cannabis use disorder status was associated with lower fluid intelligence (all p < 0.005). No other significant associations were present. Limitations: The sample was limited to young adults aged 22­36 years. The measures of cannabis involvement were relatively coarse. Conclusion: Beyond an array of potential confounders, recent cannabis use was associated with deficits in memory and psychomotor performance, and cannabis use disorder was associated with lower overall cognitive functioning in a large normative sample of adults. The findings pertaining to recent use have particular relevance for occupational settings.

Associations Between Drinking and Cortical Thickness in Younger Adult Drinkers: Findings From the Human Connectome Project.

BACKGROUND: Previous neuroimaging studies examining relations between alcohol misuse and cortical thickness have revealed that increased drinking quantity and alcohol-related problems are associated with thinner cortex. Although conflicting regional effects are often observed, associations are generally localized to frontal regions (e.g., dorsolateral prefrontal cortex [DLPFC], inferior frontal gyrus [IFG], and anterior cingulate cortex). Inconsistent findings may be attributed to methodological differences, modest sample sizes, and limited consideration of sex differences. METHODS: This study examined neuroanatomical correlates of drinking quantity and heavy episodic drinking in a large sample of younger adults (N = 706; Mage  = 28.8; 51% female) using magnetic resonance imaging data from the Human Connectome Project. Exploratory analyses examined neuroanatomical correlates of executive function (flanker task) and working memory (list sorting). RESULTS: Hierarchical linear regression models (controlling for age, sex, education, income, smoking, drug use, twin status, and intracranial volume) revealed significant inverse associations between drinks in past week and frequency of heavy drinking and cortical thickness in a majority of regions examined. The largest effect sizes were found for frontal regions (DLPFC, IFG, and the precentral gyrus). Follow-up regression models revealed that the left DLPFC was uniquely associated with both drinking variables. Sex differences were also observed, with significant effects largely specific to men. CONCLUSIONS: This study adds to the understanding of brain correlates of alcohol use in a large, gender-balanced sample of younger adults. Although the cross-sectional methodology precludes causal inferences, these findings provide a foundation for rigorous hypothesis testing in future longitudinal investigations.

Technological advances in the assessment of impulse control in offenders: A systematic review.

Deficits in impulse control have been linked to criminal offending, risk of recidivism, and other maladaptive behaviours relevant to the criminal justice system (e.g. substance use). Impulse control can be conceptualized as encompassing the broad domains of response inhibition and impulsive/risky decision-making. Advancements in technology have led to the development of computerized behavioural measures to assess performance in these domains, such as go/no-go and delay discounting tasks. Despite a relatively large literature examining these tasks in offenders, findings are not universally consistent. This systematic review aims to synthesize the literature using computerized neurocognitive tasks to assess two domains of impulse control in offenders: response inhibition and impulsive/risky decision-making. The review included 28 studies from diverse geographic locations, settings, and offender populations. The results largely support the general conclusion that offenders exhibit deficits in impulse control compared with non-offenders, with studies of response inhibition more consistently reporting differences than studies using impulsive and risky decision-making tasks. Findings are discussed in the context of contemporary neuroimaging research emphasizing dysfunction in prefrontal cortex as a key contributor to impulse control deficits in offenders.

Neuroanatomical foundations of delayed reward discounting decision making.

Resolving tradeoffs between smaller immediate rewards and larger delayed rewards is ubiquitous in daily life and steep discounting of future rewards is associated with several psychiatric conditions. This form of decision-making is referred to as delayed reward discounting (DRD) and the features of brain structure associated with DRD are not well understood. The current study characterized the relationship between gray matter volume (GMV) and DRD in a sample of 1038 healthy adults (54.7% female) using cortical parcellation, subcortical segmentation, and voxelwise cortical surface-based group analyses. The results indicate that steeper DRD was significantly associated with lower total cortical GMV, but not subcortical GMV. In parcellation analyses, less GMV in 20 discrete cortical regions was associated with steeper DRD. Of these regions, only GMV in the middle temporal gyrus (MTG) and entorhinal cortex (EC) were uniquely associated with DRD. Voxelwise surface-based analyses corroborated these findings, again revealing significant associations between steeper DRD and less GMV in the MTG and EC. To inform the roles of MTG and EC in DRD, connectivity analysis of resting state data (N = 1003) using seed regions from the structural findings was conducted. This revealed that spontaneous activity in the MTG and EC was correlated with activation in the ventromedial prefrontal cortex, posterior cingulate cortex, and inferior parietal lobule, regions associated with the default mode network, which involves prospection, self-reflective thinking and mental simulation. Furthermore, meta-analytic co-activation analysis using Neurosynth revealed a similar pattern across 11,406 task-fMRI studies. Collectively, these findings provide robust evidence that morphometric characteristics of the temporal lobe are associated with DRD preferences and suggest it may be because of their role in mental activities in common with default mode activity.

Association between overall rate of change in rising breath alcohol concentration and the magnitude of acute tolerance of subjective intoxication via the Mellanby method.

OBJECTIVE: The magnitude of acute tolerance is a strong predictor of the development of longer-term chronic tolerance and plays a decisive role in risky decisions (e.g., driving after drinking). Therefore, it is important to identify factors that increase the magnitude of this adaptive process. This study explored whether acute tolerance magnitude varied as a function of the overall rate of increase in breath alcohol concentration (BrAC). METHODS: Twenty-nine young adult social drinkers (M age = 22.55, SD = 3.10; 62.1% women) consumed a moderate dose of alcohol (men: 0.86 g/kg, women: 0.75 g/kg) in a controlled laboratory setting. Subjective intoxication was assessed at matched BrACs (~0.060 g/dl) on each limb of the BrAC curve. RESULTS: Hierarchical regression results indicated that faster overall increases in BrAC on the ascending limb were associated with greater acute tolerance for subjective intoxication ratings (p < .01, R2  = .29). CONCLUSIONS: These results present some of the first evidence that faster increases in BrAC may be associated with greater acute tolerance, as indicated by greater reduction in subjective intoxication across the limbs of the BrAC curve. This greater reduction may, in turn, promote heavier drinking and/or engagement in behaviors for which one is unfit (e.g., driving after drinking).

Automating Scoring of Delay Discounting for the 21- and 27-Item Monetary Choice Questionnaires.

Delay discounting describes the process wherein rewards lose value as a function of their delayed receipt; how quickly rewards lose value is termed the rate of delay discounting. Rates of delay discounting are robust predictors of much behavior of societal importance. One efficient approach to obtaining a human subject's rate of delay discounting is via the 21- and 27-item Monetary Choice Questionnaires, brief dichotomous choice tasks that assess preference between small immediate and larger delayed monetary outcomes. Unfortunately, the scoring procedures for the Monetary Choice Questionnaires are rather complex, which may serve as a barrier to their use. This report details a freely available Excel-based spreadsheet tool that automatically scores Monetary Choice Questionnaire response sets, using both traditional and contemporary/advanced approaches. An overview of the Monetary Choice Questionnaire and its scoring algorithm is provided. We conclude with general considerations for using the spreadsheet tool.

Understanding the effects of stress and alcohol cues on motivation for alcohol via behavioral economics.

BACKGROUND: Psychological stress and alcohol cues are common antecedents of both ongoing drinking and relapse. One candidate mechanism of risk from these factors is acute increases in craving, but experimental support for this hypothesis is mixed. Furthermore, the combination of stress and cues has been largely unstudied. The current study employed a behavioral economic approach to investigate the combined roles of psychosocial stress and alcohol cues on motivation for alcohol. METHODS: In a sample of 84 adult heavy drinkers, we examined the effects of an acute laboratory stress induction and an alcohol cue exposure on subjective craving and stress, arousal, and behavioral economic decision making. Primary dependent measures included an intertemporal cross-commodity multiple-choice procedure (ICCMCP), incorporating both price and delay elements, an alcohol purchase task (APT), measuring alcohol demand, and a monetary delay discounting task, measuring intertemporal choice. RESULTS: The stress induction significantly increased stress, craving, and the incentive value of alcohol on the ICCMCP and APT. Stress-related increases in value on the ICCMCP were mediated by increased alcohol demand. Exposure to alcohol cues only significantly affected craving, APT breakpoint, and arousal. Delay discounting was not affected by either stress or cues. CONCLUSIONS: These results reveal unique behavioral economic dimensions of motivation for alcohol following acute stress and an alcohol cue exposure. More broadly, as the first application of this approach to understanding the role of stress in drug motivation, these findings support its utility and potential in future applications.

Left-digit price effects on smoking cessation motivation.

BACKGROUND: Cigarette price increases have been associated with increases in smoking cessation, but relatively little is known about this relationship at the level of individual smokers. To address this and to inform tax policy, the goal of this study was to apply a behavioural economic approach to the relationship between the price of cigarettes and the probability of attempting smoking cessation. METHODS: Adult daily smokers (n=1074; ie, 5+ cigarettes/day; 18+ years old; ≥8th grade education) completed in-person descriptive survey assessments. Assessments included estimated probability of making a smoking cessation attempt across a range of cigarette prices, demographics and nicotine dependence. RESULTS: As price increases, probability of making a smoking cessation attempt exhibited an orderly increase, with the form of the relationship being similar to an inverted demand curve. The largest effect size increases in motivation to make a quit attempt were in the form of 'left-digit effects,' (ie, maximal sensitivity across pack price whole-number changes; eg, US$5.80-6/pack). Significant differences were also observed among the left-digit effects, suggesting the most substantial effects were for price changes that were most market relevant. Severity of nicotine dependence was significantly associated with price sensitivity, but not for all indices. CONCLUSIONS: These data reveal the clear and robust relationship between the price of cigarettes and an individual's motivation to attempt smoking cessation. Furthermore, the current study indicates the importance of left-digit price transitions in this relationship, suggesting policymakers should consider relative price positions in the context of tax changes.

Dissociable brain signatures of choice conflict and immediate reward preferences in alcohol use disorders.

Impulsive delayed reward discounting (DRD) is an important behavioral process in alcohol use disorders (AUDs), reflecting incapacity to delay gratification. Recent work in neuroeconomics has begun to unravel the neural mechanisms supporting DRD, but applications of neuroeconomics in relation to AUDs have been limited. This study examined the neural mechanisms of DRD preferences in AUDs, with emphasis on dissociating activation patterns based on DRD choice type and level of cognitive conflict. Heavy drinking adult men with (n = 13) and without (n = 12) a diagnosis of an AUD completed a monetary DRD task during a functional magnetic resonance imaging scan. Participant responses were coded based on choice type (impulsive versus restrained) and level of cognitive conflict (easy versus hard). AUD+ participants exhibited significantly more impulsive DRD decision-making. Significant activation during DRD was found in several decision-making regions, including dorsolateral prefrontal cortex (DLPFC), insula, posterior parietal cortex (PPC), and posterior cingulate. An axis of cognitive conflict was also observed, with hard choices associated with anterior cingulate cortex and easy choices associated with activation in supplementary motor area. AUD+ individuals exhibited significant hyperactivity in regions associated with cognitive control (DLPFC) and prospective thought (PPC) and exhibited less task-related deactivation of areas associated with the brain's default network during DRD decisions. This study provides further clarification of the brain systems supporting DRD in general and in relation to AUDs.

Perceptions and Attitudes Related to Driving after Cannabis Use in Canadian and US Adults.

BACKGROUND: This study examined the risk perceptions related to driving after cannabis use (DACU) among Canadian and US adults who used cannabis in the past six months. METHODS: Perceptions of danger, normative beliefs, perceived likelihood of negative consequences, and other driving-related variables were collected via online surveys in Canadian (n = 158; 50.0% female, 84.8% White, mean age = 32.73 years [SD = 10.61]) and US participants (n = 678; 50.9% female, 73.6% White, mean age = 33.85 years [SD = 10.12]). Driving cognitions and DACU quantity/frequency were compared between samples using univariate analyses of variance, and Spearman's (ρ) correlations were performed to examine associations between driving cognitions and DACU quantity/frequency. RESULTS: The two samples did not significantly differ in self-reported level of cannabis use, lifetime quantity of DACU, or the number of times they drove within two hours of cannabis use in the past three months (Ps > .12). Compared to US participants, Canadians perceived driving within two hours of cannabis use as more dangerous (P < 0.001, ηp2 = 0.013) and reported more of their friends would disapprove of DACU (P = 0.03, ηp2 = 0.006). There were no differences in the number of friends who would refuse to ride with a driver who had used cannabis (P = 0.15) or the perceived likelihood of negative consequences (Ps > 0.07). More favorable perceptions were significantly correlated with greater lifetime DACU and driving within two hours of use (ρ = 0.25-0.53, Ps < 0.01). CONCLUSIONS: These findings reveal differences in distal risk factors for DACU between Canada and the US and may inform prevention efforts focusing on perceptions of risk and social acceptance of DACU.

Early substance use and the school environment: A multilevel latent class analysis.

Background: Early substance use is associated with increased risks for mental health and substance use problems which are compounded when using several substances (i.e., polysubstance use). A notable increase in substance use occurs when adolescents transition from elementary to secondary schooling. Objective: This study seeks to characterize student and school classes of substance use. Methods: A cross-sectional multilevel latent class analysis and regression was conducted on a representative sample of 19,130 grade 6-8 students from 180 elementary schools in Ontario, Canada to: 1) identify distinct classes of student substance use; 2) identify classes of schools based on student classes; and 3) explore correlates of these classes, including mental health, school climate, belonging, safety, and extracurricular participation. Results: Two student and two school classes were identified. 4.1% of students were assigned to the high probability of early polysubstance use class while the remaining 95.9% were in the low probability class. Students experiencing depressive and externalizing symptoms had higher odds of being in the early polysubstance use class (Odds Ratio [OR]s=1.1-1.25). At the school level, 19% of schools had higher proportions of students endorsing polysubstance use. Perceptions of positive school climate, belonging, and safety increased the odds of students being in the low probability of early polysubstance use student-level class (ORs=0.85-0.93) and lower probability of early polysubstance use school-level class. Associations related to extracurricular participation were largely not statistically significant. Conclusions: Student and school substance use classes may serve as targets for tailored prevention and early interventions. Results support examining school-based interventions targeting school climate, belonging, and safety.

Contexte: L'utilisation précoce de substances est associée à des risques accrus pour la santé mentale et les problèmes liés à l'utilisation de substances qui sont aggravés lorsque plusieurs substances sont utilisées (c.-à-d. utilisation de polysubstances). Une augmentation notable de l'utilisation de substances se produit quand les adolescents passent du cours primaire au cours secondaire. Objectif: La présente étude cherche à caractériser l'utilisation de substances chez les classes d'élèves et d'écoles. Méthodes: Une analyse transversale et une régression des classes latentes multi-niveaux ont été menées sur un échantillon représentatif de 19 130 élèves de la 6e à la 8e année de 180 écoles primaires de l'Ontario, Canada, pour: 1) identifier les classes d'élèves distinctes utilisant des substances; 2) identifier les classes d'écoles d'après les classes d'élèves; et 3) explorer les corrélats de ces classes, notamment la santé mentale, le climat scolaire, l'appartenance, la sécurité, et la participation extrascolaire. Résultats: Deux classes d'élèves et deux classes d'écoles ont été identifiées. Des élèves au nombre de 4,1 % ont été assignés à la classe probabilité élevée d'une utilisation précoce de polysubstances alors que les 95,9 % restants étaient dans la classe probabilité faible. Les élèves souffrant de dépression et de symptômes externalisants avaient des probabilités plus élevées d'être dans la classe utilisation précoce de polysubstances (Rapport de cotes [RC] = 1,1­1,25). Au niveau des écoles, 19 % d'entre elles avaient des proportions plus élevées d'élèves approuvant l'utilisation de polysubstances. Les perceptions positives du climat scolaire, de l'appartenance et de la sécurité accroissaient les probabilités d'élèves étant dans la classe d'élèves faible probabilité d'utilisation précoce de polysubstances (RC = 0,85­0,93) et une probabilité plus faible de la classe d'écoles ayant une utilisation précoce de polysubstances. Les associations liées à une participation extrascolaire étaient largement non significatives statistiquement. Conclusions: Les classes d'utilisation de substances d'élèves et d'écoles peuvent servir de cibles pour une prévention adaptée et des interventions précoces. Les résultats soutiennent l'examen des interventions en milieu scolaire qui ciblent le climat scolaire, l'appartenance et la sécurité.

Adaptation of commodity purchase tasks to identify substitutable substance-free alternative activities for alcohol use.

Behavioral economic frameworks emphasize the importance of contextual influences on alcohol use; therefore, identifying relative demand for alcohol versus other commodities is of importance. Cross-commodity purchase tasks allow participants to make choices across multiple concurrently available commodities and can thereby pinpoint interactions among those commodities. These tasks may help identify relevant substance-free alternative activities to target in alcohol treatment by determining whether the activity functions as a substitute for alcohol use. While substance-free activity promotion is a promising behavioral component of alcohol interventions, no research to-date has used behavioral economic methods to assess the substitutability of alternative activities for alcohol use. The present studies were preliminary assessments of novel single- and cross-commodity purchase tasks of various alternative activities (e.g., exercise, hobbies, civic involvement). Participants in Study 1 recruited from Amazon's Mechanical Turk (n = 110) were administered a series of novel activity purchase tasks and an alcohol purchase task. Results showed excellent fit of the exponential demand equation to activity purchase task data and provided initial support for adaptation of purchase task methodology to alternative activity demand. In Study 2, participants recruited from Amazon's Mechanical Turk (n = 108) were administered both single-commodity and cross-commodity purchase tasks of alcohol and exercise. While most participants demonstrate independent consumption of alcohol and exercise, a subset of participants substituted exercise for alcohol as indicated by quantitative cross-price elasticity indices. These response patterns highlight the importance of individual differences and hold implications for recovery efforts that promote alternative activity engagement and public policy. (PsycInfo Database Record (c) 2024 APA, all rights reserved).