A web-based episodic specificity and future thinking session modulates delay discounting in cannabis users

Positive autobiographical memory recall does not influence temporal discounting: an internal meta-analysis of experimental studies

People tend to discount the value of future rewards as the delay to receiving them increases. This phenomenon, known as temporal discounting, may underlie many impulsive behaviors, such as drug abuse and overeating. Given the potential role of temporal discounting in maladaptive behaviors, many efforts have been made to find experimental manipulations that reduce temporal discounting. One class of manipulations that has held some promise involves recalling positive autobiographical memories prior to making intertemporal choices. Just as imagining positive future events has been shown to reduce temporal discounting, a few studies have shown that recalling positive past events reduces temporal discounting, especially if memory retrieval evokes positive affective states, such as gratitude and nostalgia. However, we failed to replicate these findings. Here we present an internal meta-analysis combining data from 14 studies (n = 758) that involved within-subjects positive memory recall-based manipulations. In each study, temporal discounting was assessed using a monetary intertemporal choice task. The average effect size was not significantly different from zero. This finding helps elucidate the neurocognitive mechanisms of temporal discounting; whereas engaging the episodic memory system to imagine future events might promote more patience, engaging the episodic memory system to imagine past events does not.

Effectiveness and feasibility of the self-administered and repeated episodic future thinking exercises in smoking cessation

Delay discounting (DD) is associated with smoking behavior and relapses. Episodic future thinking (EFT) is one of the leading interventions shown to reduce DD. The 1-month follow-up study with 60 participants that employed EFT as active intervention and episodic recent thinking (ERT) as control intervention was conducted in participants receiving smoking cessation treatment. In EFT group, there was significant decrease in DD rates from pre-intervention to post-intervention (p = 0.009), whereas no significant change was observed in ERT group (p = 0.497). DD rates in EFT group did not change significantly over 1 month (p = 0.059), while decrease was detected in ERT group (p = 0.011). Smoking cessation rates between groups were similar (p = 0.486). Adherence with completing follow-up evaluation forms and performing relevant exercises was higher in EFT group (p = 0.038, p = 0.006). Adding EFT to usual smoking cessation treatment did not increase smoking cessation rates, however feasibility of the self-administered exercises needs to be improved to clarify clinical effects.

Art-delivered episodic future thinking reduces delay discounting: A phase IIa proof-of-concept trial

INTRODUCTION

High rates of delay discounting (DD), or the preference for immediate rewards over delayed rewards, is associated with substance use disorder (SUD). Lower rates of DD predict better treatment outcomes, and thus strategies that reduce DD may support SUD recovery. The process of vividly imagining a future event, known as episodic future thinking (EFT), may be a particularly viable approach to reduce DD. Some limited research has examined delivery of EFT in treatment settings, using verbal prompts that are typical of studies in non-treatment settings. We propose that the creation of visual art represents a unique alignment of the purpose of EFT with an innovative delivery modality in treatment settings.

METHODS

This single arm, proof-of-concept trial evaluated art-delivered EFT (ArtEFT) to reduce DD in a sample of women (N = 39) in a residential SUD treatment center. Participants engaged in a single, 1-h ArtEFT session during which they engaged in EFT and created a visual representation using art materials. The study collected DD measures for hypothetical money ($50 and $1000 magnitude conditions) before and after ArtEFT.

RESULTS

Using area-under-the-curve (AUCord) as the index of DD, the study observed predicted changes following the ArtEFT session. The ANOVA revealed statistically significant main effects of both magnitude [F(1,38) = 11.184, p = .002] and time [F(1. 38) = 4.731, p = .036], with a non-significant interaction [F(1,38) = 3.821, p = .058].

CONCLUSION

This study reveals promising preliminary indicators that art may be an effective modality to deliver EFT, with particular advantages for implementation given the popularity of art programming in SUD treatment programs.

Imagining the future can shape the present: A systematic review of the impact of episodic future thinking on substance use outcomes

OBJECTIVE

The combination of the high prevalence of problematic substance use and substance use disorders (SUD) with the low rates of spontaneous remission continues to generate interest in the development of novel and efficacious interventions. Theoretically, episodic future thinking (EFT) is capable of targeting various underlying psychological and neurobiological substrates of SUD by traversing various research domain criteria systems.

METHOD

The systematic review examines EFT as a potentially efficacious intervention for problematic substance use and SUD. The review follows the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. We examined 46 full-text studies (from 1,238 total records obtained from APA PsycInfo and Pubmed databases and reference list search), which yielded a final sample of 16 studies.

RESULTS

The studies showed heterogeneity in their risk of bias, EFT protocols, and control conditions. Overall, EFT showed benefits in reducing self-reported or task-based substance use-related outcomes.

CONCLUSIONS

Future research directions include establishing the feasibility of EFT, examining the generalizability in decreasing real-world substance use, identifying mediators and moderators of EFT outcomes, and determining the sustainability of EFT effects over time. EFT has high potential for dissemination. Limitations and potential for future research are discussed. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

Patients with cocaine use disorder exhibit reductions in delay discounting with episodic future thinking cues regardless of incarceration history

Research examining episodic future thinking (EFT; i.e., imagining oneself in future contexts) in community samples has demonstrated reduced discounting of delayed rewards when personalized event cues are included to prompt EFT related to reward latencies. While this EFT effect was recently demonstrated in individuals with substance use disorders, it is not yet known if it manifests similarly in individuals with and without a significant incarceration history-the latter being at elevated risk for negative outcomes including criminal recidivism. Individuals with cocaine use disorder (n = 35) identified personally-relevant future events and participated in a computerized delay discounting task, involving decisions between smaller immediate rewards or larger delayed rewards with and without EFT cues. Individuals with (n = 19) and without (n = 16) a significant history of incarceration were identified using the Addiction Severity Index-Lite. A significant reduction in discounting rates was observed when event cues were included to promote EFT (p = 0.02); however, there was no main effect of incarceration history on discounting behavior, or interaction between episodic future thinking condition and incarceration history. Results suggest personalized cues included to evoke EFT reduce discounting behavior in individuals with cocaine use disorder, regardless of incarceration history. EFT-based interventions may therefore have promise to reduce impulsive decision-making in individuals with cocaine use disorder with and without a significant history of incarceration, potentially supporting improved outcomes with respect to both substance use and future criminality.

The hidden-zero effect in male individuals with opioid use disorder

Background: Explicitly expressing the hidden opportunity cost in intertemporal choice significantly reduces healthy participants' delay discounting - a phenomenon named the "hidden-zero effect," which is undetermined in individuals with substance use disorder (SUD).Objectives: This study aimed to determine whether the hidden-zero effect occurs among individuals with opioid use disorder (OUD) and the degree to which this effect differs between the OUD group and healthy controls.Methods: In two different experiments, Exp#1) 29 male individuals with OUD (13.5 ± 6.0 months abstinence) and 29 male controls performed an intertemporal choice task (ICT); Exp#2) 28 male individuals with OUD (17.5 ± 5.6 months abstinence) and 27 male controls performed a delay discounting task (DDT). The OUD group was recruited from a mandatory treatment, and controls from WeChat. There were two choice conditions in both two tasks: the hidden-zero (H0) condition (standard), and the explicit-zero (E0) condition (explicitly expressing opportunity cost).Results: Compared with the H0 condition, all participants' delay discounting was significantly decreased in the E0 condition (ps < .05, ηp2 = 0.254, 0.110). There was no significant difference in the changed degree between these two groups in either experiment (ps > .05). The delay discounting of the OUD group was significantly higher than that of controls only in Experiment 2 (p < .001, ηp2 = 0.376).Conclusion: This study extended the population in which the hidden-zero effect occurs to individuals with OUD. With respect to delay discounting, the hidden-zero effect benefit did not differ in OUD and control participants.

Initial evaluation of domain-specific episodic future thinking on delay discounting and cannabis use

Episodic Future Thinking (EFT), mental simulation of personally relevant and positive future events, may modulate delay discounting (DD) in cannabis users. Whether EFT impacts cannabis use, whether DD mediates this effect, and whether EFT can be enhanced by prompting future events across specific life domains is unknown. Active, adult cannabis users (n = 90) recruited from Amazon mTurk and Qualtrics Panels were administered an Episodic Specificity Induction (ESI) to enhance quality of imagined events before being randomized to EFT, domain-specific-EFT (DS-EFT), or Episodic Recent Thinking (ERT). All participants created four, positive life events; DS-EFT participants imagined social, leisure, health, and financial events. Event-quality ratings were assessed (e.g., enjoyment). DD was assessed at baseline (Day 1), post-intervention (Days 2-4), and follow-up (Days 9-12). Cannabis use was assessed at baseline and follow-up. Differences in change in days and grams of cannabis use between conditions and mediation of changes in use by DD were examined. No differences in DD were observed between conditions. DS-EFT, but not EFT, showed significantly greater reductions in grams (d = .54) and days of cannabis use (d = .50) than ERT. DS-EFT and EFT demonstrated significantly greater event-quality ratings than ERT (ds > .55). EFT-based interventions showed potential for reducing cannabis use. Unexpectedly, effects on DD did not mediate this effect. Further testing with larger samples of cannabis users is needed to better understand EFT's mechanisms of action and determine optimal implementation strategies. (PsycInfo Database Record (c) 2022 APA, all rights reserved).

(Non-) impact of task experience on behavioral economic decision-making

Behavioral economic research has been widely conducted via crowdsourcing resources to evaluate novel task designs or pilot interventions. One under recognized and yet-to-be tested concern is the impact of non-naïvety (i.e., prior task exposure) on behavioral economic task performance. We evaluated the influence of non-naïvety on task performance in two popular areas of behavioral economic research: behavioral economic demand and delay discounting. Participants (N = 485) recruited using Amazon Mechanical Turk (mTurk) completed alcohol and soda purchase tasks and delay discounting tasks for monetary and alcohol outcomes. Equivalence of responding and effect sizes with clinical variables were compared based on prior task experience. Over one quarter of participants reported demand task experience (26.9%) and nearly half endorsed delay discounting task experience (48.6%). Statistically equivalent responding was observed for alcohol purchase task data with less-than-small effect size differences based on task experience (d = 0.01-0.13). Similar results were observed for a soda purchase task thereby supporting generalization to a non-alcohol commodity. Measures of convergent and discriminant validity for behavioral economic demand indicated medium-to-large and stimulus-specific effect sizes with little variation based on prior task exposure. Delay discounting for money and alcohol showed some sensitivity to prior task experience (i.e., less steep discounting for non-naïve participants), however these effects were attenuated after accounting for group differences in alcohol use. These findings support the fidelity of behavioral economic task outcomes and emphasize that participant non-naïvety in crowdsourcing settings may minimally impact performance on behavioral economic assays commonly used in behavioral and addiction science. (PsycInfo Database Record (c) 2022 APA, all rights reserved).

How do cannabis users mentally travel in time? Evidence from an fMRI study of episodic future thinking

RATIONALE

Episodic future thinking (EFT) is a cognitive function that allows individuals to imagine novel experiences that may happen in the future. Prior studies show that EFT is impaired in different groups of substance users. However, there is no evidence regarding the neurobiological mechanisms of EFT in cannabis users.

OBJECTIVES

We aimed to compare brain activations of regular cannabis users and non-using controls during an EFT fMRI task. Exploratory analyses were also conducted to investigate the association between EFT and cannabis use variables (e.g., duration of use, age onset, frequency of use).

METHODS

Twenty current cannabis users and 22 drug-naïve controls underwent an fMRI scanning session while completing a task involving envisioning future-related events and retrieval of past memories as a control condition. The EFT fMRI task was adapted from the autobiographical interview and composed of 20 auditory cue sentences (10 cues for past and 10 cues for future events). Participants were asked to recall a past or generate a future event, in response to the cues, and then rate their vividness after each response.

RESULTS

We found that cannabis users compared to non-user controls had lower activation within the cerebellum, medial and superior temporal gyrus, lateral occipital cortex, and occipital fusiform gyrus while envisioning future events. Cannabis users rated the vividness of past events significantly lower than non-users (P < 0.005). There were marginal group differences for rating the vividness of future events (P = 0.052). Significant correlations were also found between the medial and superior temporal gyrus activities and behavioral measures of EFT and episodic memory.

CONCLUSIONS

Cannabis users, compared to drug-naïve controls, have lower brain activation in EFT relevant regions. Thus, any attempts to improve aberrant EFT performance in cannabis users may benefit from EFT training.

Effects of episodic future thinking on reinforcement pathology during smoking cessation treatment among individuals with substance use disorders

RATIONALE

Reinforcer pathology (RP) is a theoretical model based on two processes: delay discounting (DD) and drug demand. Given that RP has been shown to have a predictive value on smoking behaviors, several studies have explored which interventions can reduce RP. Consistent with the RP framework, episodic future thinking (EFT) has shown effects on treatment outcomes and RP processes. The vast majority of studies that assess the effects of EFT on RP consist of experimental studies, and no previous research has tested these effects in a clinical sample of smokers.

OBJECTIVES

The primary aim of this study was to assess the effects of EFT on RP throughout the course of a smoking cessation intervention in smokers with substance use disorders (SUDs).

METHODS

Participants were randomized to cognitive behavior therapy (CBT) + EFT (n = 39) or CBT + EFT + contingency management (n = 33). Cotinine, frequency of EFT practices, cigarette purchase task (CPT), and DD were evaluated in treatment sessions. Mixed-effects model repeated measures analysis was used to explore DD and CPT in-treatment changes as a function of EFT practices and cotinine levels.

RESULTS

Greater practice of the EFT component significantly reduced cigarette demand (p < .020) as well as DD (p = .003). Additionally, a greater reduction in cotinine levels coupled with greater EFT practice led to a greater decrease in cigarette demand (p < .014).

CONCLUSIONS

EFT reduced the two facets of RP in treatment-seeking smokers with SUDs.

Development of Goal Management Training+ for Methamphetamine Use Disorder Through Collaborative Design

BACKGROUND

Methamphetamine use disorder (MUD) is associated with executive dysfunctions, which are linked with poorer treatment outcomes including earlier drop out and relapse. However, current treatments for MUD do not address executive functions. Goal Management Training (GMT) is an evidence-based cognitive remediation program for executive dysfunction, although required modifications to enhance its relevance and application within addiction treatment settings. This study aimed to (1) tailor GMT to the key cognitive deficits and typical treatment duration of MUD; (2) explore consumers' (people with MUD) engagement with the revised program; (3) implement a prototype of the program with consumers; and (4) present the manualized standard administration to clinical service providers.

METHODS

We followed the Medical Research Council Complex Interventions Framework and employed an evidence- and person-based intervention development process. We used a four-phased approach and collaborated with neuropsychology experts, design researchers in healthcare, consumers with MUD, and clinical service providers. Each aim was addressed in a separate study phase; including content refinement and review with neuropsychology experts (phase 1), intervention design and collaboration with consumers (phase 2), prototype development and review with consumers (phase 3), and final program modifications and review with clinical stakeholders (phase 4).

RESULTS

Findings from phase 1 indicated support for targeting four cognitive processes (attention, impulse control, goal setting, and decision-making). Key feedback included the need to help habitualize cognitive strategies and to guide consumers in applying these strategies in emotionally salient situations. Findings from phases 2 and 3 indicated consumer support for the program strategies and materials but highlighted the need to further enhance the personal relevance of specific content and journal activities. Findings from phase 4 provided clinicians support for the revised program but indicated an opportunity to minimize unintended effects. We present the intervention materials for the final revised program, Goal Management Training⁺ (GMT⁺), in line with TIDieR guidelines.

CONCLUSIONS

GMT⁺ targets key cognitive processes and is sensitive to the clinical needs of people with MUD. Our intervention development process was important for informing the active ingredients and materials for GMT⁺, and indicated initial consumer and provider acceptability prior to conducting a clinical trial.

A meta-analysis of the effects of episodic future thinking on delay discounting

Delay discounting (DD) refers to the phenomenon in which the subjective value of future rewards is reduced over time. There are individual differences in the DD rate, and increased discounting has been observed in those with various psychiatric disorders. Episodic future thinking (EFT) is the act of vividly imagining events that may happen in the future. Studies have shown that EFT could reduce DD, although inconsistent results have been reported. The aim of this meta-analysis was to clarify the efficacy with which EFT reduces DD and to identify potential moderators. Forty-seven studies (including 63 contrasts) were included in the final analysis. EFT was found to significantly reduce DD (Hedges' g = 0.52). Moderator analysis showed that positive EFT (g = 0.64) was more effective in reducing DD than EFT with the valence not specifically mentioned (g = 0.28) and EFT with neutral or negative valence (g = -0.03). In addition, several factors related to the control task and DD task were related to the efficacy of EFT to reduce DD. These findings have implications for using EFT to reduce DD in the future.

Brief Negative Affect Focused Functional Imagery Training Abolishes Stress-Induced Alcohol Choice in Hazardous Student Drinkers

Introduction

Imagery-based stress management therapies are effective at reducing alcohol use. To explore the therapeutic mechanism, the current study tested whether brief functional imagery training linked to personal negative affect drinking triggers would attenuate sensitivity to noise stress-induced alcohol seeking behaviour in a laboratory model.

Methods

Participants were UK-based hazardous student drinkers (N = 61, 80.3% women, aged 18–25) who reported drinking to cope with negative affect. Participants in the active intervention group (n = 31) were briefly trained to respond to personal negative drinking triggers by retrieving an adaptive strategy to mitigate negative affect, whereas participants in the control group (n = 30) received risk information about binge drinking at university. The relative value of alcohol was then measured by preference to view alcohol versus food pictures in two-alternative choice trials, before (baseline) and during noise stress induction.

Results

There was a significant two-way interaction (p < .04) where the control group increased their alcohol picture choice from baseline to the noise stress test (p < .001), whereas the active intervention group did not (p=.33), and the control group chose alcohol more frequently than the active group in the stress test (p=.03), but not at baseline (p=.16).

Conclusions

These findings indicate that imagery-based mood management can protect against the increase in the relative value of alcohol motivated by acute stress in hazardous negative affect drinkers, suggesting this mechanism could underpin the therapeutic effect of mood management on drinking outcomes.

Voluntary exercise as a treatment for incubated and expanded drug craving leading to relapse to addiction: Animal models

Drug addiction is a chronic relapsing disorder, as more than 80% of former drug users relapse within a year after quit attempts have ended. This review examines incubated craving that develops over long periods of weeks to months after addictive drug use ends, when rats are given a small priming exposure to the formerly used drug, and a large amount of drug seeking occurs, reflecting large increases in craving over time. Expanded craving occurs when not only the recently-used drug, but other related or unrelated drugs of abuse elicit drug seeking that leads to relapse behavior, including common drugs like caffeine or nicotine, Thus, expanded craving is an increase in the conditions that elicit relapse, such as, a variety of drugs, and it persists weeks after drug use ends. Incubated and expanded craving occur with several drugs of abuse, and these forms of craving, can last for weeks to months and end in relapse. Voluntary physical exercise, blocked incubated cocaine craving, and expanded heroin craving elicited by multiple conditions was reduced in female and male rats. This review examines voluntary physical exercise as a long-term, self-initiated, and self-sustainable treatment that reduces long-term drug craving leading to relapse.

Episodic future thinking for smoking cessation in individuals with substance use disorder: Treatment feasibility and acceptability

BACKGROUND

Smokers with substance use disorders (SUD) smoke approximately four times more than the general population. Current efforts are focused on improving smoking cessation treatments for this population. Episodic future thinking (EFT), a novel intervention aimed at decreasing impulsive choice, has shown promising results for reducing cigarette demand in experimental settings. This feasibility study sought to examine the feasibility and preliminary EFT effects on delay discounting (DD) and nicotine intake reductions throughout treatment.

METHOD

Smokers in substance use treatment (N = 29; 75.9% males) received an 8-week cognitive-behavioral treatment (CBT) + EFT for smoking cessation. The study assessed feasibility through successful recruitment rates, retention, and adherence to treatment. Participants' satisfaction acted as our acceptability measure. We computed nonparametric range tests to analyze changes in continuous variables.

RESULTS

Among interested individuals, 42 (43.75%) met the inclusion criteria, and 29 entered the treatment program. Rate of treatment completion was 65.5% (19/29). Mean (SD) sessions attended were 7(1.11), and mean patient satisfaction rating with treatment was 8.83/10. The study observed low compliance with EFT, with 15.8% (3/19) of patients practicing at least 50% of the requested times.

CONCLUSIONS

CBT + EFT is acceptable for the SUD population. However, future studies should implement some adjustments to improve the adherence and feasibility of EFT, such as reducing the number of practices and temporal intervals in EFT events. Given the small sample size, and the absence of a control group, future larger scale trials are needed to elucidate EFT effects on DD and smoking cessation.

Evaluating effects of episodic future thinking on valuation of delayed reward in cocaine use disorder: a pilot study

Background: Episodic future thinking (EFT; i.e., envisioning oneself in future contexts) has been demonstrated to reduce discounting of future reward in healthy adults. While this approach has the potential to support future-oriented decision-making in substance use recovery, the impact of EFT on discounting behavior in illicit stimulant users has not yet been evaluated.Objectives: This pilot study aimed to (1) assess the feasibility of utilizing EFT methods in individuals with cocaine use disorder (CUD) and (2) conduct preliminary measurement of the EFT effect on discounting behavior in this population.Methods: Eighteen treatment-seeking individuals with CUD (17 males) were interviewed about positive and neutral events expected to occur at a range of future latencies. Future event information identified by participants was subsequently included on a subset of trials in an intertemporal choice task to promote EFT; within-subject differences in discounting between standard and EFT conditions were evaluated.Results: Participants identified relevant events and demonstrated decreased discounting of future reward when event descriptors were included (relative to discounting without event descriptors; p = .039). It was further noted that most events identified by participants were goals, rather than plans or significant dates.Conclusion: While methods previously used to study the effect of EFT on discounting behavior in healthy individuals are also effective in individuals with CUD, methodological factors - including types of events identified - should be carefully considered in future work. These preliminary findings suggest that EFT can reduce impulsive decision-making in cocaine use disorder and may therefore have therapeutic value.

The Effects of Cannabis Use Frequency and Episodic Specificity Training on the Recall of Specific and Rewarding Events

Background: Growing evidence implicates subjective episodic memory, the retrieval of detailed, integrated, and personally relevant past events, as a marker of cognitive vulnerability in mental disorders. Frequent and problematic cannabis use is associated with deficits in objective episodic memory (verbal memory), but the relationship between subjective episodic memory deficits and frequency of cannabis use is unknown. Further, whether a brief intervention designed to enhance the specificity of event retrieval, such as the Episodic Specificity Induction (ESI), might effectively target such deficits among regular cannabis users is unexamined. This study was designed to examine subjective episodic memory as a potential marker of cognitive vulnerability among frequent cannabis users. Methods: Active cannabis users (n = 133) recruited from Amazon Mechanical Turk or Qualtrics Panels were randomized to receive an ESI-control or ESI session and were separated into those who used cannabis 1-25 days in the past month (low to moderate frequency group) and those who used 26-30 days (high frequency group), which facilitated a low to moderate use/ESI-control group (n = 78), low to moderate use/ESI group (n =15), high-use/ESI-control group (n = 20), and high-use/ESI group (n = 20). Following the ESI or ESI-control intervention, participants selected four, positive events from the prior day, described the who, what, and where of the events, and rated how specific (vividness) and rewarding (enjoyable, importance, and exciting) each event was on a 0-100 scale. Four two-way ANCOVAs (demographics and problematic cannabis use covariates) were performed to examine the effects of frequency of cannabis use group and ESI group on the specificity and reward ratings. Results: Lower vividness and excitement ratings were reported for those with high relative to low to moderate cannabis use frequency patterns (p < 0.05). Those who received ESI reported greater vividness, excitement, and importance ratings than the ESI-control group (p < 0.01). No significant interactions between frequency and ESI were found. Conclusion: Findings from the current exploratory study provide initial evidence suggesting that more frequent cannabis use may be associated with the retrieval of less specific and rewarding events relative to less frequent users. Further, ESI may improve such deficits. Future studies that recruit larger and more clinically serious samples of cannabis users appear warranted.

Sifting through the weeds: Relationships between cannabis use frequency measures and delay discounting

BACKGROUND

Delay Discounting (DD) relates to more frequent cannabis use, but results are variable, potentially because of variations in whether integrated or single-item measures are used, and whether the timeframe of measures is narrow or broad. Explicating the relationship between DD and cannabis use may result from comparing use indices that vary on these characteristics.

METHODS

This online study of current cannabis users (n = 1,800) assessed DD and three cannabis use frequency items: number of days of use in the past month, times used per day, and weekly-monthly use. A fourth index derived with Latent Class Analysis (LCA) integrated days per month and times per day to try to better characterize frequency patterns. Effect sizes reflecting relations between cannabis use frequency indices and DD were compared.

RESULTS

Three frequency classes emerged from the LCA (Low-Moderate-High). DD was significantly associated with times per day (r = 0.11, d = 0.21), days of use (r = 0.09, d = 0.18), and the LCA index (r = 0.06, d = 0.13), but not weekly-monthly use (r = 0.04, d = 0.09). Times per day was more strongly related to DD than LCA classes (p < 0.01) and weekly-monthly use (p < 0.05), but not days of use (p = 0.66). Days of use exhibited a stronger relationship with DD than weekly-monthly use (p < 0.001), but not LCA classes (p = 0.06).

CONCLUSIONS

Cannabis use frequency measures with narrower timeframes may demonstrate stronger positive relationships to DD. The LCA index did not improve the relationship between frequency and DD, potentially because of shared variance between use days and times per day. Specific characteristics of cannabis use frequency may be particularly indicative of excessive DD.