About

Elizabeth R Aston is an Associate Professor (Research) in the Department of Behavioral and Social Sciences at Brown University. She received her Ph.D. in Neuroscience from Wake Forest School of Medicine in 2012, where her research focused on the estimation of breath alcohol concentration and simulated driving behavior among individuals who engage in heavy episodic drinking. Her research interests include examining predictors of cannabis use disorder severity among regular cannabis users and investigating the relative reinforcing value of cannabis through behavioral economic measures. Dr. Aston was awarded a K01 career development award from the National Institute on Drug Abuse to conduct qualitative and quantitative research aimed at modifying and validating a behavioral economic measure of cannabis demand. She joined Brown University to continue this research and to receive training in qualitative methods, laboratory marijuana administration methodology, behavioral economic theory, and advanced data analysis.

Research topics

• Medicine
• Psychiatry
• Clinical psychology
• Psychology
• Environmental health
• Microeconomics
• Biology
• Family medicine
• Economics

Selected publications

• Is toke cheap? Correspondence between cannabis demand and purchase in the laboratory

  Addiction · 2026-01-12

  articleOpen access1st authorCorresponding

  Abstract Background and aims The typical Marijuana Purchase Task (MPT) assesses hypothetical demand (i.e. relative reinforcing value) for cannabis across escalating prices. Cannabis demand has been related to use frequency, craving, cannabis use disorder symptoms and cue‐exposure response, among other outcomes. This study assessed MPT performance for hypothetical consumption in relation to in vivo behavior in the laboratory wherein rewards were actualized. Methods Individuals endorsing cannabis use at least twice weekly ( n = 92) participated in a laboratory cannabis self‐administration study. Participants completed MPTs for Hypothetical and Actual cannabis. One trial (i.e. amount purchased at specified price) was randomly selected from the Actual MPT and participants with non‐zero value trials ( n = 81) were permitted to smoke up to that amount during a 1‐hour session in the laboratory. Results Bivariate Pearson correlations demonstrated that cannabis consumption preferences were highly similar across the Hypothetical and Actual MPT at the price ( r s = 0.45–0.81) and index ( r s = 0.46–0.81) level. However, mean O max (i.e. maximum expenditure), P max (i.e. price at maximum expenditure) and breakpoint (i.e. price suppressing consumption to zero), were statistically significantly higher ( d s = 0.47–0.51), and elasticity (i.e. consumption decline rate relative to price increase) was statistically significantly lower ( d = −0.58) for the Actual MPT compared with the Hypothetical MPT; this was also evident at certain price points. Self‐reported anticipated consumption was statistically significantly related to the amount of cannabis smoked during self‐administration (R 2 = 0.66; P < 0.001) and was not moderated by price of the randomly selected trial. Conclusions High correspondence between Hypothetical and Actual Marijuana Purchase Task (MPT) performance in a laboratory setting suggests that hypothetical versions of the MPT may be broadly valid measures of cannabis demand. The robust relationship between anticipated consumption and actual cannabis quantity smoked in the laboratory suggests individual self‐report accurately predicts subsequent self‐administration, further supporting the construct validity of hypothetical MPTs.

  PublisherOA PDFDOI

• Using prospective mixed methods to investigate the effect of the COVID‐19 pandemic on cannabis demand

  Journal of the Experimental Analysis of Behavior · 2025-02-25

  articleOpen access1st authorCorresponding

  Following the COVID-19 pandemic, it is vital to understand how major global stressors influence substance use, including cannabis-related outcomes. The Marijuana Purchase Task assesses hypothetical cannabis demand (i.e., relative reinforcing value) and can detect contextual alterations. This study paired prospective cannabis demand assessment with qualitative inquiry to explore how COVID-19 impacted cannabis use behavior. Individuals previously enrolled in a laboratory cannabis administration study opted in to a remote follow-up survey (n = 41, 46% female). Participants were categorized as those who did or did not increase use based on self-reported changes in cannabis flower use and provided contextual explanations regarding pandemic-related influences on cannabis outcomes. General linear models with repeated measures examined mean differences in demand by occasion (i.e., before/during COVID-19), group (i.e., those who did/did not increase use), and their interaction. Those who increased use exhibited significantly higher demand during the pandemic; those who did not increase use exhibited similar demand across time revealing a Group × Time interaction. Thematic analysis contextualized quantitative findings, explaining external influences that affect use and demand (e.g., changes in cost, access, environment). COVID-19 differentially impacted cannabis use and demand, with prepandemic use affecting trajectories. Contextual influences (i.e., availability, free time, income) facilitate the escalation of use under conditions of extreme global stress.

  PublisherOA PDFDOI

• Assessing behavioural economic demand for morphine after an acute dose in individuals with- and without childhood trauma: a double-blind, randomised, controlled trial

  Psychopharmacology · 2025-12-04

  articleOpen access

  Abstract Background Childhood trauma is associated with positive subjective responses to acute opioids in the laboratory. Yet, its impact on behavioural economic demand for opioids remains unclear. Because demand can predict future use and misuse, we investigated whether individuals with childhood trauma also display greater demand for opioids in the laboratory. Methods This secondary analysis used data from a double-blind, randomised, controlled, counterbalanced trial. Across two sessions, individuals with ( n = 26) and without ( n = 21) childhood trauma received a high (0.15 mg/kg) and low (0.01 mg/kg) dose of intramuscular morphine 120 min before a hypothetical purchase task. Participants also regularly reported their subjective desire for the study drug. Area under the consumption and expenditure curves, and specific demand indices ( O max , P max , breakpoint , intensity , elasticity ), were analysed with non-parametric mixed models. Results Consumption and expenditure for low dose morphine was lower in the childhood trauma group when compared to high dose morphine in this group, and low dose morphine in the control group ( p s ≤ 0.03). Consistent results were obtained for specific demand indices O max , P max , and breakpoint , but not intensity or elasticity . Positive correlations between subjective desire and consumption and expenditure were only observed in the childhood trauma group ( Tau-c = 0.24–0.34, p s ≤ 0.03). Conclusion Under laboratory conditions, desires to use opioids among individuals with childhood traumas may not manifest in strong intentions to acquire these drugs. Diverging results from psychometric measures of subjective and economic opioid value highlight the need for future research to explore contextual and resilience factors to understand how problematic opioid use emerges after childhood traumas.

  PublisherOA PDFDOI

• Acute Effects of Cannabis on Alcohol Craving and Consumption: A Randomized Controlled Crossover Trial

  American Journal of Psychiatry · 2025-11-19 · 8 citations

  articleOpen access

  OBJECTIVE: Cannabis use is strongly linked with heavy drinking and worse alcohol treatment outcomes; however, it may also contribute to decreased alcohol consumption. To date, no human studies have established a causal effect of cannabis on alcohol motivation. The aim of this double-blind crossover randomized clinical trial was to examine dose-dependent acute effects of delta-9-tetrahydrocannabinol (THC) on alcohol craving and consumption. METHODS: Across three experimental days, 157 participants reporting heavy alcohol use and cannabis use two or more times weekly were randomized to smoke cannabis cigarettes containing 7.2% THC, 3.1% THC, or 0.03% THC (placebo), followed by exposures to neutral and personalized alcohol cues and an alcohol choice task for alcohol self-administration. A total of 138 participants completed two or more experimental sessions (mean age, 25.6 years [SD=5.1]; 35% women; 45% racial/ethnic minorities). Primary outcomes included craving, Alcohol Craving Questionnaire-Short Form, Revised (ACQ-SF-R), and an alcohol urge question; the secondary outcome was percent of total available milliliters of alcohol consumed. RESULTS: There were no significant effects of cannabis on ACQ-SF-R ratings after smoking and during alcohol cue exposure, but 7.2% THC reduced alcohol urge immediately after smoking. Participants consumed significantly less alcohol after smoking cannabis with 3.1% THC and 7.2% THC, reducing consumption by 19% and 27%, respectively. CONCLUSIONS: Following overnight cannabis abstinence, smoking cannabis acutely decreased alcohol consumption compared to placebo. Further controlled research on a variety of cannabinoids is needed to inform clinical alcohol treatment guidelines.

  PublisherOA PDFDOI

• Online conversations on perceived stigma among pregnant individuals who use cannabis

  Drug and Alcohol Dependence Reports · 2025-06-18

  articleOpen access

  Perinatal cannabis use (PCU) is a controversial topic, as it is associated with negative neonatal and maternal outcomes. However, PCU persists, often reported in the context of perceived symptom management, and those who engage in PCU can face significant stigma. Such stigma can deter individuals from discussing their cannabis use with support persons, potentially exacerbating negative health outcomes for the parent and child. The current study explores how PCU stigma manifests and is navigated in online communities, focusing on discussions within an online space for individuals who use cannabis during pregnancy. First, a random sample of 10 threads per month from June 2020 to May 2021 were extracted from a cannabis-focused forum on a pregnancy and parenting website. Next, analyses involved a two-cycle coding process (i.e., topical followed by conceptual) to identify key themes surrounding stigma in the context of PCU. Three primary themes were identified: 1) experiencing stigma (e.g., familial and societal sources of judgment, emotional responses such as guilt and frustration); 2) contradictions in substance stigma, highlighting the contrast between societal attitudes and expectations towards cannabis versus alcohol or tobacco use during pregnancy; and 3) challenging stigma, in which participants actively provide support, share personal experiences, and offer evidence to counteract stigma. Online communities may play a critical role in combating stigma, offering a platform for connection, support, and education. Results emphasize that a nonjudgmental approach to information dissemination may be more effective. Understanding stigma is essential for developing effective interventions and reducing the harms of PCU. • Perinatal cannabis use is increasing, despite known risks to parent and child health. • Stigma around perinatal cannabis use affects access to care and support networks. • Qualitative analysis of online forum with two-cycle coding to identify stigma themes. • Users report stigma from society and peers, reporting guilt and frustration. • Contradictions emerge between societal views on cannabis vs. alcohol/tobacco use.

  PublisherDOI

• Human research methods for studying operant demand

  Elsevier eBooks · 2025-01-01 · 1 citations

  book-chapter
  PublisherDOI

• Day-level negative outcomes of failed control over drinking.

  Journal of Psychopathology and Clinical Science · 2025-12-11

  articleOpen access

  = 203 young adults reporting heavy drinking, 57% female, 74% White) were recruited between 2021 and 2023. Participants completed 28 days of ecological momentary assessment of drinking intentions, alcohol use, blackouts, and other alcohol-related consequences. Daily FC was operationalized as (a) unplanned drinking (i.e., drinking after earlier day denial of intentions to drink), (b) surpassing intended levels of intoxication reported early evening (predrinking), and (c) surpassing intended levels of intoxication reported at first drink. In multilevel models, unplanned (vs. planned) drinking days were related to fewer drinks and lower odds of blackouts. Getting more intoxicated than intended early evening was related to more drinks and higher odds of experiencing 1+ other negative consequences; getting more intoxicated than intended at the first drink was related to all three outcomes: more drinks and higher odds of blackouts/other consequences. Day-level risks of FC depend on how it is operationalized. In this sample, the heaviest and most problematic drinking appears to occur on planned, rather than unplanned, drinking days and when intended intoxication levels are exceeded. Efforts to reduce heavy drinking and negative outcomes may benefit from incorporating skills to facilitate adherence to predefined plans for desired intoxication levels. (PsycInfo Database Record (c) 2026 APA, all rights reserved).

  PublisherDOI

• Social context and impaired control over alcohol use during naturally occurring drinking episodes

  Psychopharmacology · 2025-10-15 · 1 citations

  articleOpen access
  PublisherOA PDFDOI

• Contributors

  Elsevier eBooks · 2025-01-01

  book-chapter
  PublisherDOI

• Pass the Keys: Using Behavioral Economics to Explore Driving After Cannabis Use

  Substance Use &amp Addiction Journal · 2025-08-10 · 1 citations

  article

  Background: Controlled studies show cannabis impairs driving performance and may increase crash risk. Recent approaches in behavioral economics have used marijuana purchase tasks (MPTs) to understand driving after cannabis use (DACU). One factor that may influence DACU is the latency between smoking and having to drive. Method: A crowdsourced sample of adults who smoke cannabis at least monthly (n = 167; 77% White; 45% women; mean age = 38.55) completed 4 MPTs in the context of different instructional vignettes with different smoked cannabis use and driving latencies (non-driving; 20 minutes, 1 hour, and 6 hours). Participants reported frequency and perceived dangerousness of DACU. Demand indices included intensity (consumption when free), breakpoint (last price with any consumption), O max (maximum expenditure), and P max (price at O max ). Results: Repeated measures analysis of variance revealed main effects of latency on all demand indices (ps <0.001), attributed to lower demand in each of the DACU conditions relative to the non-driving condition (ps <0.015; ds = 0.09-1.52). Demand increased in a linear fashion as latency increased. Participants with a history of DACU showed a blunted reduction in demand (except breakpoint) at each latency compared to participants with no DACU history (ps <0.043; η p 2 = 0.008-0.043). Perceived dangerousness was inversely correlated with demand (except breakpoint; r s −0.29 to −0.62, ps <0.05). Conclusions: Cannabis demand is sensitive to specific parameters surrounding driving contingencies, and risk perceptions may contribute to these associations. Future research is needed to extend these findings and identify other factors impacting DACU, such as different routes of administration or road conditions.

  PublisherDOI

Recent grants

• Behavioral Economic Analysis of Demand for Marijuana

  NIH · $902k · 2015–2021

• Administrative Core

  NIH · $34.9M · 2019–2029

Frequent coauthors

• Jane Metrik

  Rutgers, The State University of New Jersey

  128 shared

• James MacKillop

  St. Joseph’s Healthcare Hamilton

  70 shared

• Samantha G. Farris

  Rutgers, The State University of New Jersey

  58 shared

• Jasjit S. Ahluwalia

  Providence College

  30 shared

• Ana M. Abrantes

  24 shared

• Christopher W. Kahler

  Brown University

  23 shared

• Michael Amlung

  University of Kansas

  21 shared

• Jennifer E. Merrill

  20 shared

Education

• Ph.D.

  Wake Forest University

  2012

Awards & honors

• K01 career development award from the National Institute on…