The effects of perceived quality on the behavioural economics of alcohol, amphetamine, cannabis, cocaine, and ecstasy purchases

Contextual and psychosocial factors influencing drug reward in humans: The importance of non-drug reinforcement

The reinforcing efficacy, or behavior-strengthening effect, of a substance is a critical determinant of substance use typically quantified by measuring behavioral allocation to the substance under schedules of reinforcement with escalating response requirements. Although responses on these tasks are often used to indicate stable reinforcing effects or trait-level abuse potential for an individual, task designs often demonstrate within-person variability across varying degrees of a constraint within experimental procedures. As a result, quantifying behavioral allocation is an effective approach for measuring the impact of contextual and psychosocial factors on substance reward. We review studies using laboratory self-administration, behavioral economic purchase tasks, and ambulatory assessments to quantify the impact of various contextual and psychosocial factors on behavioral allocation toward consumption of a substance. We selected these assessment approaches because they cover the translational spectrum from experimental control to ecological relevance, with consistent support across these approaches representing greater confidence in the effect. Conceptually, we organized factors that influence substance value into two broad categories: factors that influence the cost/benefit ratio of the substance (social context, stress and affect, cue exposure), and factors that influence the cost/benefit ratio of an alternative (alternative non-drug reinforcers, alternative drug reinforcers, and opportunity costs). We conclude with an overview of future research directions and considerations for clinical application.

Drivers of purchase decisions for cannabis products among consumers in a legalized market: a qualitative study

Background

Cannabis was legalized in Canada for non-medical use in 2018. The goal of legalization was to improve health and safety by creating access to regulated products, with accurate product labels and warnings and no risk of contamination. However, more than 2 years post-legalization, a large proportion of purchases are still suspected to be through unlicensed retailers. This study sought to identify the factors that influenced the purchase decisions of cannabis consumers in Newfoundland and Labrador (NL).

Methods

Semi-structured focus groups and interviews were conducted in NL with individuals who were > 19 and had purchased cannabis within the last 12 months. All sessions were conducted virtually, audio-recorded, and transcribed. A thematic analysis was conducted, and two members of the research team coded the data using NVivo. A combination of deductive and inductive coding was carried out, themes from the literature were identified, and new themes from the transcripts were discovered. A final coding template of the data was agreed upon by the team through discussion and consensus.

Results

A total of 23 individuals (30% women) participated, with 83% coming from urban areas. While all cannabis product types were discussed, the conversation naturally focused on dried flower products. Participants discussed a variety of considerations when making purchase decisions categorized around five broad themes: 1) price, 2) quality, 3) packaging and warnings, 4) the source of the cannabis, and 5) social influences. The price difference between licensed and un-licensed sources was commonly discussed as a factor that influenced purchase decisions. Product quality characteristics (e.g. size, color, moisture content) and social influences were also considered in purchase decisions. Participants were generally indifferent to packaging and warning labels but expressed concern about the excessive packaging required for regulated products.

Conclusion

This study explores the many attributes that influence purchase decisions for dried leaf cannabis. Understanding the drivers of purchase decisions can help inform policy reforms to make regulated cannabis products more appealing to consumers. Further research is needed to measure the effect of each attribute on cannabis purchase decisions.

Characteristics that influence purchase choice for cannabis products: a systematic review

Introduction

When non-medical cannabis use became legal, government regulators implemented policies to encourage safer consumption through access to a regulated market. While this market is growing, sales still occur through unregulated channels. This systematic review identifies factors influencing cannabis purchasing to help policymakers understand why consumers still purchase illicit market cannabis (registered with PROSPERO CRD42020176079).

Methods

A comprehensive search strategy included databases in health, business, and social science fields (inception to June 2020). Studies were eligible for inclusion if they were conducted with persons who purchase cannabis and examine at least one attribute that would influence purchase choice and were published in the English language. Studies could be of any methodological design. Two independent reviewers completed two levels of screening, and all extraction was verified by a second reviewer. A qualitative synthesis of the findings was completed. The quality of the included studies was assessed using the Mixed Methods Appraisal Tool.

Results

Of the 4839 citations screened, 96 were eligible for full-text review and 35 were included in the final synthesis. Aspects of price were the most common factors (27 studies). Twenty studies measured price elasticity; most studies found that demand was price inelastic. Many other attributes were identified (e.g., product quality, route of administration, product recommendations, packaging), but none were explored in depth. Eleven studies addressed aspects of product quality including demand elasticity based on quality, potency, and aroma. Studies also explored consumer-perceived “quality” but provided no definition; differences in quality appeared to impact consumer choice. Smoking cannabis appeared to be the preferred route of administration but was only examined in three studies. There was insufficient data to understand in the impact of other attributes on choice. There appeared to be preference heterogeneity for different attributes based on the consumer’s experience, reason for use, and gender.

Conclusion

While price influences choices, demand is relatively inelastic. This suggests that consumers may be seeking lowest-cost, unregulated cannabis to avoid reducing consumption. Beyond price, there is a significant gap in our understanding of consumer choices. Perceived quality does appear to impact choice; however, more research is needed due to the lack of a recognized definition for cannabis quality.

Supplementary Information

The online version contains supplementary material available at 10.1186/s42238-022-00117-0.

Does cannabis complement or substitute alcohol consumption? A systematic review of human and animal studies

BACKGROUND

Whether alcohol and cannabis complement or substitute each other has been studied for over two decades. In the changing cannabis policy landscape, debates are moving rapidly and spill-over effects on other substances are of interest.

AIMS

update and extend a previous systematic review, by: (a) identifying new human behavioural studies reporting on substitution and/or complementarity of alcohol and cannabis, and (b) additionally including animal studies.

METHODS

We replicated the search strategy of an earlier systematic review, supplemented with a new search for animal studies. Search results were crossed checked against the earlier review and reference lists were hand searched. Findings were synthesised using a narrative synthesis.

RESULTS

Sixty-five articles were included (64 in humans, one in animals). We synthesised findings into categories: patterns of use, substitution practices, economic relationship, substance use disorders, policy evaluation, others and animal studies. Overall, 30 studies found evidence for substitution, 17 for complementarity, 14 did not find evidence for either, and four found evidence for both.

CONCLUSIONS

Overall, the evidence regarding complementarity and substitution of cannabis and alcohol is mixed. We identified stronger support for substitution than complementarity, though evidence indicates different effects in different populations and to some extent across different study designs. The quality of studies varied and few were designed specifically to address this question. Dedicated high-quality research is warranted.

One Is Not Enough: Understanding and Modeling Polysubstance Use

Substance use disorder (SUD) is a chronic, relapsing disease with a highly multifaceted pathology that includes (but is not limited to) sensitivity to drug-associated cues, negative affect, and motivation to maintain drug consumption. SUDs are highly prevalent, with 35 million people meeting criteria for SUD. While drug use and addiction are highly studied, most investigations of SUDs examine drug use in isolation, rather than in the more prevalent context of comorbid substance histories. Indeed, 11.3% of individuals diagnosed with a SUD have concurrent alcohol and illicit drug use disorders. Furthermore, having a SUD with one substance increases susceptibility to developing dependence on additional substances. For example, the increased risk of developing heroin dependence is twofold for alcohol misusers, threefold for cannabis users, 15-fold for cocaine users, and 40-fold for prescription misusers. Given the prevalence and risk associated with polysubstance use and current public health crises, examining these disorders through the lens of co-use is essential for translatability and improved treatment efficacy. The escalating economic and social costs and continued rise in drug use has spurred interest in developing preclinical models that effectively model this phenomenon. Here, we review the current state of the field in understanding the behavioral and neural circuitry in the context of co-use with common pairings of alcohol, nicotine, cannabis, and other addictive substances. Moreover, we outline key considerations when developing polysubstance models, including challenges to developing preclinical models to provide insights and improve treatment outcomes.

The drug purity discounting task: Ecstasy use likelihood is reduced by probabilistic impurity according to harmfulness of adulterants

BACKGROUND

Ecstasy typically contains adulterants in addition to, or in lieu of, MDMA which may pose a greater risk to users than MDMA itself. The current study aimed to evaluate the effectiveness of adulterant-related informational prompts in reducing Ecstasy use using a novel probability discounting task.

METHODS

An online sample of past-month Ecstasy users (N = 278) were randomized to one of four different framing prompt conditions: no prompt; a prompt describing MDMA's effects; a prompt describing adulterants as inert "filler"; or a prompt describing adulterants as pharmacologically-active, potentially-harmful compounds. Each prompt contained general, potential public-health information that was not specifically related to subsequent behavioral tasks. All participants then completed an identical Drug Purity Discounting Task, in which they indicated the likelihood of using a sample of Ecstasy across different probabilities of the sample being impure, and then completed a hypothetical Ecstasy purchasing task.

RESULTS

Likelihood of Ecstasy use decreased as impurity probability increased across conditions. Ecstasy use likelihood was highest in the "inert" prompt condition, whereas pharmacologically-active adulterant or adulterant-nonspecific prompts resulted in comparably low likelihood of use. Ecstasy-use likelihood did not differ among conditions when the likelihood of sample impurity was 0. Ecstasy purchasing did not differ among groups. Inelastic purchasing was associated with greater likelihood of using potentially-impure Ecstasy.

CONCLUSIONS

Altogether, these data highlight the necessity of education regarding pharmacologically-active, rather than inert, adulterants in Ecstasy, and suggest that increased access to drug checking kits and services may mitigate some of the harms associated with Ecstasy use.

Variation in cannabis potency and prices in a newly legal market: evidence from 30 million cannabis sales in Washington state

AIMS

To (1) assess trends and variation in the market share of product types and potency sold in a legal cannabis retail market and (2) estimate how potency and purchase quantity influence price variation for cannabis flower.

DESIGN

Secondary analysis of publicly available data from Washington State's cannabis traceability system spanning 7 July 2014 to 30 September 2016. Descriptive statistics and linear regressions assessed variation and trends in cannabis product variety and potency. Hedonic regressions estimated how purchase quantity and potency influence cannabis flower price variation.

SETTING

Washington State, USA.

PARTICIPANTS

(1) A total of 44 482 176 million cannabis purchases, including (2) 31 052 123 cannabis flower purchases after trimming price and quantity outliers.

MEASUREMENTS

Primary outcome measures were (1) monthly expenditures on cannabis, total delta-9-tetrahydrocannabinol (THC) concentration and cannabidiol (CBD) concentration by product type and (2) excise tax-inclusive price per gram of cannabis flower. Key covariates for the hedonic price regressions included quantity purchased, THC and CBD.

FINDINGS

Traditional cannabis flowers still account for the majority of spending (66.6%), but the market share of extracts for inhalation increased by 145.8% between October 2014 and September 2016, now comprising 21.2% of sales. The average THC-level for cannabis extracts is more than triple that for cannabis flowers (68.7% compared to 20.6%). For flower products, there is a statistically significant relationship between price per gram and both THC [coefficient = 0.012; 95% confidence interval (CI) = 0.011-0.013] and CBD (coefficient = 0.017; CI = 0.015-0.019). The estimated discount elasticity is -0.06 (CI = -0.07 to -0.05).

CONCLUSIONS

In the state of Washington, USA, the legal cannabis market is currently dominated by high-THC cannabis flower, and features growing expenditures on extracts. For cannabis flower, both THC and CBD are associated with higher per-gram prices, and there are small but significant quantity discounts.

The effects of perceived quality on behavioral economic demand for marijuana: A web-based experiment

BACKGROUND

Given the growing legalization of recreational marijuana use and related increase in its prevalence in the United States, it is important to understand marijuana's appeal. We used a behavioral economic (BE) approach to examine whether the reinforcing properties of marijuana, including "demand" for marijuana, varied as a function of its perceived quality.

METHODS

Using an innovative, Web-based marijuana purchase task (MPT), a sample of 683 young-adult recreational marijuana users made hypothetical purchases of marijuana across three qualities (low, mid and high grade) at nine escalating prices per joint, ranging from $0/free to $20.

RESULTS

We used nonlinear mixed effects modeling to conduct demand curve analyses, which produced separate demand indices (e.g., P_max, elasticity) for each grade of marijuana. Consistent with previous research, as the price of marijuana increased, marijuana users reduced their purchasing. Demand also was sensitive to quality, with users willing to pay more for higher quality/grade marijuana. In regression analyses, demand indices accounted for significant variance in typical marijuana use.

CONCLUSIONS

This study illustrates the value of applying BE theory to young adult marijuana use. It extends past research by examining how perceived quality affects demand for marijuana and provides support for the validity of a Web-based MPT to examine the appeal of marijuana. Our results have implications for policies to regulate marijuana use, including taxation based on the quality of different marijuana products.

A behavioral economic approach to assessing demand for marijuana

In the United States, marijuana is the most commonly used illicit drug. Its prevalence is growing, particularly among young adults. Behavioral economic indices of the relative reinforcing efficacy (RRE) of substances have been used to examine the appeal of licit (e.g., alcohol) and illicit (e.g., heroin) drugs. The present study is the first to use an experimental, simulated purchasing task to examine the RRE of marijuana. Young-adult (M age = 21.64 years) recreational marijuana users (N = 59) completed a computerized marijuana purchasing task designed to generate demand curves and the related RRE indices (e.g., intensity of demand-purchases at lowest price; Omax-max. spent on marijuana; Pmax-price at which marijuana expenditure is max). Participants "purchased" high-grade marijuana across 16 escalating prices that ranged from $0/free to $160/joint. They also provided 2 weeks of real-time, ecological momentary assessment reports on their marijuana use. The purchasing task generated multiple RRE indices. Consistent with research on other substances, the demand for marijuana was inelastic at lower prices but became elastic at higher prices, suggesting that increases in the price of marijuana could lessen its use. In regression analyses, the intensity of demand, Omax, and Pmax, and elasticity each accounted for significant variance in real-time marijuana use. These results provide support for the validity of a simulated marijuana purchasing task to examine marijuana's reinforcing efficacy. This study highlights the value of applying a behavioral economic framework to young-adult marijuana use and has implications for prevention, treatment, and policies to regulate marijuana use.

Traditional Chinese medicine diagnoses in persons with ketamine abuse

OBJECTIVES

To explore the distribution of TCM patterns in ketamine users and the inter-rater reliability of TCM diagnosis among TCM practitioners.

METHODS

Eighty-four subjects recruited from substance abuse clinics and non-governmental counseling services catering for ketamine abusers were examined by one or two TCM practitioners. The distribution and inter-rater reliability of the TCM diagnoses between the two TCM practitioners were described and measured.

RESULTS

Seven TCM patterns were differentiated. The four most common patterns were the Heart Yin deficiency (29.8%), Kidney Yang deficiency (26.2% Kidney Yin deficiency (19.0%), and Spleen Yang deficiency (14.3%). The agreement between the two TCM practitioners was 59%; the kappa for the three most common patterns was 0.472 (P = 0.003). The proportion of men was lower in the Kidney Yin deficiency group (18.8%), in comparison to the Heart Yin deficiency (60.0%, P = 0.009) and Kidney Yang deficiency group (59.1%, P = 0.013).

CONCLUSION

The differences between the TCM groups in terms of the source of referral and number of drug uses other than ketamine were of borderline significance. Further research should focus on validating diagnostic tools and improving inter-rater reliability in TCM to enhance the quality of clinical trials of TCM treatments for ketamine abuse.