Promoting self-change in cannabis use disorder: Findings from a randomized trial.

Background: A growing body of literature supports the efficacy of cognitive-behavioral therapy (CBT) and motivational interviewing (MI) for the treatment of problematic cannabis use, diagnostically referred to as cannabis use disorder, though most individuals do not access formal treatment. Stepped-care-type models emphasize interventions across a continuum of severity and there is a need for more treatment options across this continuum. This project focused on the evaluation of the least intensive of the individual interventions - promotion of self-directed recovery. Methods: Using a three-arm randomized control trial design, adults (N = 186) with problematic cannabis use and who wished to recover with minimal professional support were recruited from across Canada and randomized to receive a self-directed treatment workbook based on CBT and MI principles (WB; n = 61), the workbook plus a single MI session (WMI; n = 61) or a delayed treatment control (DT; n = 65) condition. Participants completed 3-month and 6-month follow-up assessments. Results: Across conditions, GEE modeling revealed that the baseline to 3-month slopes differed significantly from zero, ps < 0.001. Participants in the WMI condition reduced their frequency of use to a greater extent than the WB alone, p = 0.005, and DT groups, p = 0.02. Chi-square analysis revealed that participants in the WMI condition also showed greater rates of abstinence at 3-months follow-up than participants in the WB or DT condition, p = 0.046. Changes in the frequency of cannabis use between 3-months and 6-months did not differ significantly between groups, ps > 0.05. For quantity of cannabis use, a significant effect of time emerged, p = 0.002. However, no between-group effects were significant from baseline to 3-months, or from 3- to 6-months, ps > 0.06. Conclusion: Overall, results support the utility of a brief self-directed workbook in combination with a single MI session at promoting changes in cannabis use. This self-directed intervention has the potential to fill an important need in that the self-directed intervention can attract individuals who wish to recover with minimal professional support. Clinical trial registration: [https://www.isrctn.com/], identifier [ISRCTN426 32893].

Measuring recent cannabis use across modes of delivery: Development and validation of the Cannabis Engagement Assessment.

Introduction: Methods of cannabis engagement have proliferated in recent years, which many self-report measures do not adequately capture. There is a clear need for self-report measures that capture current patterns of cannabis use across a range of methods, and that can be used to track changes over time. The current study developed the Cannabis Engagement Assessment (CEA), a self-report measure of past month cannabis use across dry flower, concentrate, and edible products. Methods: A sample of 349 participants from the undergraduate student population and broader community were recruited. To examine convergent validity of the CEA, participants completed measures of cannabis engagement, cannabis misuse, and use-related problems. To assess divergent validity, participants also completed measures of depression and alcohol use problems. Criterion and test-retest reliability were examined in a subset of 65 participants who re-completed the CEA and a timeline follow-back interview (TLFB). Results: Indicators of cannabis use frequency and quantity showed good convergence with measures of cannabis use patterns, problematic engagement, and cannabis use-related problems. Divergent validity of the CEA was supported by lower associations with alcohol use problems and depression symptoms. The CEA also showed good test-retest reliability and convergence with estimates of frequency and quantity of cannabis use from the TLFB. Conclusions: The CEA is a viable self-report measure of cannabis use that is representative of current patterns of recreational cannabis engagement. Its focus on cannabis use in the preceding 30 days also lends itself to measuring changes in use over time.

Reward-Related Decision-Making in Current and Past Disordered Gambling: Implications for Impulsive Choice and Risk Preference in the Maintenance of Gambling Disorder.

Impulsive reward-related decision-making (RRDM) is robustly associated with gambling disorder (GD), although its role in the development and perpetuation of GD is still being investigated. This project sought to examine the possible roles of impulsive and risky choice, two aspects of RRDM, in the perpetuation of GD. Additionally, the potential moderating role of comorbid substance misuse was considered. A total of 434 participants with symptoms of current GD and symptoms of concurrent substance use disorder (SUD; n = 105), current GD with past SUD (n = 98), past GD with current SUD (n = 53), or past GD with past substance use disorder (SUD; n = 92), and 96 healthy controls were recruited through MTurk. Participants completed a randomly adjusting delay discounting (a measure of impulsive choice) and probabilistic discounting (a measure of risky choice) task and self-report questionnaires of gambling participation, GD and SUD symptomology, and trait impulsivity. Although control participants showed significantly greater delay discounting compared to individuals with a current or history of GD, no significant group differences emerged between individuals with current GD or a history of GD. Individuals with current GD showed significantly less probabilistic discounting compared to individuals with a history of GD and control participants showed the greatest rates of probabilistic discounting. These effects remained after controlling for lifetime gambling symptom severity and trait impulsivity. Overall, these findings suggest a potential maintaining role of risky choice in gambling disorder, but do not support a maintaining role for impulsive choice.

Predictive utility of the brief Screener for Substance and Behavioral Addictions for identifying self-attributed problems.

BACKGROUND AND AIMS: The Brief Screener for Substance and Behavioral Addictions (SSBAs) was developed to assess a common addiction construct across four substances (alcohol, tobacco, cannabis, and cocaine), and six behaviors (gambling, shopping, videogaming, eating, sexual activity, and working) using a lay epidemiology perspective. This paper extends our previous work by examining the predictive utility of the SSBA to identify self-attributed addiction problems. METHOD: Participants (N = 6,000) were recruited in Canada using quota sampling methods. Receiver Operating Characteristics (ROCs) analyses were conducted, and thresholds established for each target behavior's subscale to predict self-attributed problems with these substances and behaviors. For each substance and behavior, regression models compared overall classification accuracy and model fit when lay epidemiologic indicators assessed using the SSBA were compared with validated screening measures to predict selfattributed problems. RESULTS: ROC analyses indicted moderate to high diagnostic accuracy (Area under the curves (AUCs) 0.73-0.94) across SSBA subscales. Thresholds for identifying self-attributed problems were 3 for six of the subscales (alcohol, tobacco, cannabis, cocaine, shopping, and gaming), and 2 for the remaining four behaviors (gambling, eating, sexual activity, and working). Compared to other instruments assessing addiction problems, models using the SSBA provided equivalent or better model fit, and overall had higher classification accuracy in the prediction of self-attributed problems. DISCUSSION AND CONCLUSIONS: The SSBA is a viable screening tool for problematic engagement across ten potentially addictive behaviors. Where longer screening tools are not appropriate, the SSBA may be used to identify individuals who would benefit from further assessment.

Gambling-related cognitive distortions mediate the relationship between depression and disordered gambling severity.

BACKGROUND AND OBJECTIVES: Symptoms of depression are highly prevalent among individuals with gambling disorder, and severity of depression is associated with severity of gambling problem. Yet, little is known about the psychological mechanisms by which symptoms of depression lead to greater gambling severity. In this study, we tested whether cognitive distortions represent one such mechanism, as cognitive distortions are key characteristics in both depression and gambling disorder and have been shown to be associated with gambling severity. METHODS: A mediation model was tested among 345 treatment-seeking individuals with gambling disorder in Sao Paulo, Brazil. The diagnosis of gambling disorder was made using semi-structured clinical interviews and participants completed psychometrically sound self-report measures of depression symptoms (Beck Depression Inventory-I), gambling-related cognitive distortions (Gamblers' Beliefs Questionnaire), and gambling severity (Gambling Symptom Assessment Scale). RESULTS: As hypothesized, increased symptoms of depression were significantly associated with both increased disordered gambling severity and increased gambling-related cognitive distortions. Further, gambling-related cognitive distortions predicted greater disordered gambling severity when controlling for depression symptomology. Results from the bootstrapping method indicated that the relationship between symptoms of depression and increased disordered gambling severity is mediated by gambling-related cognitive distortions. CONCLUSIONS: Consistent with our predictions, gambling-related cognitive distortions mediated the relationship between depression symptoms and gambling severity among a sample of treatment-seeking disordered gamblers. These results suggest that cognitive distortions may be a key intervention target for the treatment of concurrent depression and gambling disorder.

Obtaining quality data using behavioral measures of impulsivity in gambling research with Amazon's Mechanical Turk.

BACKGROUND AND AIMS: To date, no research has examined the viability of using behavioral tasks typical of cognitive and neuropsychology within addiction populations through online recruitment methods. Therefore, we examined the reliability and validity of three behavioral tasks of impulsivity common in addiction research in a sample of individuals with a current or past history of problem gambling recruited online. METHODS: Using a two-stage recruitment process, a final sample of 110 participants with a history of problem or disordered gambling were recruited through MTurk and completed self-report questionnaires of gambling involvement symptomology, a Delay Discounting Task (DDT), Balloon Analogue Risk Task (BART), Cued Go/No-Go Task, and the UPPS-P. RESULTS: Participants demonstrated logically consistent responding on the DDT. The area under the empirical discounting curve (AUC) ranged from 0.02 to 0.88 (M = 0.23). The BART demonstrated good split-third reliability (ρs = 0.67 to 0.78). The tasks generally showed small correlations with each other (ρs = ±0.06 to 0.19) and with UPPS-P subscales (ρs = ±0.01 to 0.20). DISCUSSION AND CONCLUSIONS: The behavioral tasks demonstrated good divergent validity. Correlation magnitudes between behavioral tasks and UPPS-P scales and mean scores on these measures were generally consistent with the existing literature. Behavioral tasks of impulsivity appear to have utility for use with problem and disordered gambling samples collected online, allowing researchers a cost efficient and rapid avenue for conducting behavioral research with gamblers. We conclude with best-practice recommendations for using behavioral tasks using crowdsourcing samples.

Can one simple questionnaire assess substance-related and behavioural addiction problems? Results of a proposed new screener for community epidemiology.

BACKGROUND AND AIMS: There is currently no well-validated measure that assesses a broad spectrum of substance-related and behavioural addictions in general populations. This study aimed to develop a brief self-attribution Screener for Substance and Behavioural Addictions (SSBA) to screen for four substances and six behaviours, and to compare its performance with established individual-behaviour screening instruments. DESIGN: A small, psychometrically optimal set of items to assess self-attributed indicators of addiction across alcohol, tobacco, cannabis, cocaine, gambling, shopping, videogaming, overeating, sexual activity and overworking were identified from a broader pool that was developed using a lay epidemiology qualitative approach. The suitability of the four-item single-factor solution was tested for each behaviour and scores were compared with those obtained from the sample using individual-behaviour screening instruments. SETTING AND PARTICIPANTS: Participants (n = 6000), broadly representative of the Canadian English-speaking adult population, were recruited through the Ipsos Reid Canadian Online Panel. MEASUREMENTS: Participants completed an item pool of 15 indicators of addiction for each target behaviour and a validation instrument for one randomly assigned behaviour. FINDINGS: A set of four items identified using principal component and confirmatory factor analyses demonstrated good fit and excellent internal consistency (α = 0.87-0.95) across behaviours, and good convergent validity (rs = 0.44-0.8) with extant instruments measuring similar constructs, with only one exception (r = 0.26). CONCLUSIONS: The proposed Screener for Substance and Behavioural Addiction is a reliable and valid measure assessing the lay public's self-attributed indicators of addiction across 10 substances and behaviours.

Perturbations in reward-related decision-making induced by reduced prefrontal cortical GABA transmission: Relevance for psychiatric disorders.

The prefrontal cortex (PFC) is critical for higher-order cognitive functions, including decision-making. In psychiatric conditions such as schizophrenia, prefrontal dysfunction co-occurs with pronounced alterations in decision-making ability. These alterations include a diminished ability to utilize probabilistic reinforcement in guiding future choice, and a reduced willingness to expend effort to receive reward. Among the neurochemical abnormalities observed in the PFC of individuals with schizophrenia are alterations in the production and function of the inhibitory neurotransmitter gamma-aminobutyric acid (GABA). To probe how PFC GABA hypofunction may contribute to alterations in cost/benefit decision-making, we assessed the effects GABAA-receptor antagonist bicuculline (BIC; 50 ng in 0.5 µl saline/hemisphere) infusion in the medial PFC of rats during performance on a series of well-validated cost/benefit decision-making tasks. Intra-PFC BIC reduced risky choice and reward sensitivity during probabilistic discounting and decreased the preference for larger rewards associated with a greater effort cost, similar to the behavioral sequelae observed in schizophrenia. Additional experiments revealed that these treatments did not alter instrumental responding on a progressive ratio schedule, nor did they impair the ability to discriminate between reward and no reward. However, BIC induced a subtle but consistent impairment in preference for larger vs. smaller rewards of equal cost. BIC infusion also increased decision latencies and impaired the ability to "stay on task" as indexed by reduced rates of instrumental responding. Collectively, these results implicate prefrontal GABAergic dysfunction as a key contributing factor to abnormal decision-making observed in schizophrenia and other neuropsychiatric conditions with similar neurobiological and behavioral alterations.