Alcohol Use Disorder, Alcohol Drinking
Conditions
Keywords
Alcohol, Neuroeconomics, Demand, Cues
Brief summary
This study uses techniques from an area of research known as neuroeconomics, which integrates concepts and methods from psychology, neuroscience, and economics to better understand how people make decisions and how these decisions are supported by the brain. One neuroeconomic concept that is especially relevant in the area of addictions is substance demand, or how consumption of a commodity (e.g., alcohol, tobacco, or drugs) is influenced by price and other factors. Previous studies have shown that alcohol demand is related to severity of alcohol misuse, drinking quantity/frequency, and treatment outcomes. In addition, we know that alcohol demand can also fluctuate in response to environmental cues such as alcohol-related stimuli or external contingencies such as important responsibilities the following day. These increase and decreases in consumption and value are clinically significant because they help us understand how people with alcohol use disorders are able to successfully or unsuccessfully modulate their drinking behaviors. This study is examining how the brain responds in these situations and whether these responses differ as a function of severity of alcohol misuse. This study will use functional magnetic resonance imaging (fMRI) to understand brain activity patterns associated with changes in the value of alcohol in the presence of alcohol-related beverage cues relative to neutral-related beverage cue. Participants will be non-treatment-seeking adult heavy drinkers who are recruited from the community to participate in an fMRI scan. During the scan, participants will make decisions about how many alcohol beverages they would consume (hypothetically) at various prices while their brain activity during those decisions is measured. The experimental manipulation involves an in-scanner alcohol cue exposure task in which the drinking decisions will be made after viewing high-quality images of alcoholic (beer/wine/liquor) beverages or neutral (water/juice/soft drinks) beverages.
Detailed description
Neuroeconomics integrates concepts and methods from psychology, economics, and cognitive neuroscience to understand the neurobiological foundations of decision making, and has been increasingly applied to understanding alcohol use disorder (AUD). A novel application of neuroeconomics is the study of alcohol demand, or the value of alcohol as measured by cost-benefit preferences. Alcohol demand paradigms have considerable ecological validity by measuring the impact of internal and external influences on alcohol decision-making, such as price, environmental cues, affective states, or external contingencies. Behaviorally, alcohol demand is elevated among individuals with higher levels of alcohol misuse and predicts treatment response. Alcohol demand also exhibits state-like properties, including increases following exposure to alcohol-related cues. The overall goal of the proposed studies is to characterize the neural activity that subserves these established behavioral findings using a novel functional MRI paradigm. The primary aim is to examine the patterns of neural activation underlying increases in the value of alcohol in response to alcohol cues. The study will use a within-subjects design to identify differences in neural activity associated with demand decisions following a validated in-scanner cue exposure protocol consisting of exposure to neutral beverage cues and exposure to alcohol beverage cues in a sample of adult heavy drinkers. Using a novel neuroeconomics approach, this study combines a highly ecologically-valid alcohol demand paradigm with an experimental manipulation that models clinically-relevant influences on drinking decisions. Studying these contextual influences may help clarify the neural signatures that underlie drinking moderation vs. unconstrained drinking, and how these processes are impacted by AUD. If successful, this study will provide a foundation for examining neural predictors of successful recovery or response to treatment vs. relapse. More broadly, findings from this study have high potential to significantly enhance the clinical relevance of alcohol neuroscience.
Interventions
Participants will undergo a validated in-scanner alcohol cue and neutral cue exposure protocol involving passive viewing of images of alcohol beverages (beer, wine, or liquor) and neutral beverages (water).
Sponsors
Study design
Intervention model description
Participants will undergo a validated cue exposure protocol involving exposure to neutral beverage cues followed by exposure to alcohol beverage cues
Eligibility
Inclusion criteria
* 21-55 years old; * Right-handed; * Fluent English speaker; * Heavy drinker (i.e., on average \> 14/7 drinks per week for males/females in past three months; * Average of 1 heavy drinking episode weekly (heavy drinking episode = 5+/4+ for males/females) over past three months
Exclusion criteria
* Currently receiving treatment, or seeking treatment, for alcohol related problems; * Current Diagnostic and Statistical Manual (DSM-5) substance use disorder other than alcohol or tobacco; * Weekly or more frequent use of recreational drugs; * History of schizophrenia-spectrum disorders, psychotic disorders, bipolar disorder, or PTSD; * History of neurocognitive disorder or impairment; * MRI contraindications (e.g., metal in body, history of seizure, etc.); * History of serious brain injury; * Currently taking psychotropic medications or medications that could affect cerebral blood flow; * Pregnancy (females); * Attending any study session with a positive breath alcohol concentration (BrAC \> 0.00g%)
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Alcohol Demand Intensity | Collected during each of 4 runs of the FMRI Alcohol Purchase Task. Duration of each run was approximately 6 minutes and included 26 trials. | Intensity is defined as the self-consumption in standard drinks at free price. Participants could select between 0-10 standard sized alcohol drinks on the in-scanner alcohol purchase task paradigm. The mean intensity was calculated separately for the two neutral cue runs and the two alcohol cue runs. |
| Alcohol Demand Breakpoint | Collected during each of 4 runs of the FMRI Alcohol Purchase Task. Duration of each run was approximately 6 minutes and included 26 trials. | Breakpoint is defined as the first price on the alcohol purchase task that suppressed consumption to zero drinks. The mean breakpoint was calculated separately for the two neutral cue runs and the two alcohol cue runs. |
| Alcohol Demand Omax | Collected during each of 4 runs of the FMRI Alcohol Purchase Task. Duration of each run was approximately 6 minutes and included 26 trials. | Omax is defined as the maximum total expenditure on alcohol for the in-scanner alcohol purchase task. The mean Omax was calculated separately for the two neutral cue runs and the two alcohol cue runs. |
| Alcohol Demand Elasticity | Collected during each of 4 runs of the FMRI Alcohol Purchase Task. Duration of each run was approximately 6 minutes and included 26 trials. | Elasticity is defined as the change in consumption (in drinks) as a function of increases in price per drink (in dollars). This index was modeled using an exponentiated demand curve model as reported in \[Koffarnus, M. N., Franck, C. T., Stein, J. S., & Bickel, W. K. (2015). A modified exponential behavioral economic demand model to better describe consumption data. Experimental and clinical psychopharmacology, 23(6), 504-512. https://doi.org/10.1037/pha0000045\]. This nonlinear model generates a best fitting value for an alpha parameter, reflecting the rate of change in elasticity over increasing price. Higher alpha values reflect greater elasticity (greater sensitivity in consumption with increases in price). There is no theoretical range as this is a free parameter in the model. Mean alpha values were calculated separately for the two neutral cue runs and the two alcohol cue runs. |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Alcohol Craving | Collected immediately after the first neutral cue exposure and immediately after the first alcohol cue exposure. | Subjective alcohol craving was assessed using three 100-point scales, including how much they want alcohol, crave alcohol, and their urge for alcohol. A score of 0 indicates the lowest level of craving; a score of 100 indicates the highest amount of craving. The three items were averaged into a composite craving score. |
Countries
Canada
Participant flow
Participants by arm
| Arm | Count |
|---|---|
| Alcohol Cue Exposure Within subjects assignment to receive complete both an alcohol cue exposure and neutral cue exposure in a sequential order. | 72 |
| Total | 72 |
Baseline characteristics
| Characteristic | Alcohol Cue Exposure |
|---|---|
| 30 Day Timeline Follow-Back Interview | 20.3 Drinks/week STANDARD_DEVIATION 12.9 |
| Age, Categorical <=18 years | 0 Participants |
| Age, Categorical >=65 years | 0 Participants |
| Age, Categorical Between 18 and 65 years | 72 Participants |
| Alcohol Use Disorders Identification Test (AUDIT) | 12.0 units on a scale STANDARD_DEVIATION 5.4 |
| Daily Drinking Questionnaire (DDQ) | 22.3 Drinks/week STANDARD_DEVIATION 13.1 |
| Diagnostic Assessment Research Tool (DART) for DSM-5 Alcohol Use Disorder | 49 Participants |
| Education | 16.3 Years STANDARD_DEVIATION 2 |
| Ethnicity (NIH/OMB) Hispanic or Latino | 1 Participants |
| Ethnicity (NIH/OMB) Not Hispanic or Latino | 71 Participants |
| Ethnicity (NIH/OMB) Unknown or Not Reported | 0 Participants |
| Race (NIH/OMB) American Indian or Alaska Native | 0 Participants |
| Race (NIH/OMB) Asian | 0 Participants |
| Race (NIH/OMB) Black or African American | 0 Participants |
| Race (NIH/OMB) More than one race | 5 Participants |
| Race (NIH/OMB) Native Hawaiian or Other Pacific Islander | 0 Participants |
| Race (NIH/OMB) Unknown or Not Reported | 0 Participants |
| Race (NIH/OMB) White | 67 Participants |
| Sex: Female, Male Female | 37 Participants |
| Sex: Female, Male Male | 35 Participants |
Adverse events
| Event type | EG000 affected / at risk | EG001 affected / at risk |
|---|---|---|
| deaths Total, all-cause mortality | 0 / 72 | 0 / 72 |
| other Total, other adverse events | 0 / 72 | 0 / 72 |
| serious Total, serious adverse events | 0 / 72 | 0 / 72 |
Outcome results
Alcohol Demand Breakpoint
Breakpoint is defined as the first price on the alcohol purchase task that suppressed consumption to zero drinks. The mean breakpoint was calculated separately for the two neutral cue runs and the two alcohol cue runs.
Time frame: Collected during each of 4 runs of the FMRI Alcohol Purchase Task. Duration of each run was approximately 6 minutes and included 26 trials.
| Arm | Measure | Group | Value (MEAN) | Dispersion |
|---|---|---|---|---|
| Alcohol Cue Exposure | Alcohol Demand Breakpoint | Alcohol Cue Exposure | 32.48 Dollars | Standard Error 1.45 |
| Alcohol Cue Exposure | Alcohol Demand Breakpoint | Neutral Cue Exposure | 28.77 Dollars | Standard Error 1.67 |
Alcohol Demand Elasticity
Elasticity is defined as the change in consumption (in drinks) as a function of increases in price per drink (in dollars). This index was modeled using an exponentiated demand curve model as reported in \[Koffarnus, M. N., Franck, C. T., Stein, J. S., & Bickel, W. K. (2015). A modified exponential behavioral economic demand model to better describe consumption data. Experimental and clinical psychopharmacology, 23(6), 504-512. https://doi.org/10.1037/pha0000045\]. This nonlinear model generates a best fitting value for an alpha parameter, reflecting the rate of change in elasticity over increasing price. Higher alpha values reflect greater elasticity (greater sensitivity in consumption with increases in price). There is no theoretical range as this is a free parameter in the model. Mean alpha values were calculated separately for the two neutral cue runs and the two alcohol cue runs.
Time frame: Collected during each of 4 runs of the FMRI Alcohol Purchase Task. Duration of each run was approximately 6 minutes and included 26 trials.
| Arm | Measure | Group | Value (MEAN) | Dispersion |
|---|---|---|---|---|
| Alcohol Cue Exposure | Alcohol Demand Elasticity | Neutral Cue Exposure | 0.006 drinks consumed/price (dollars) | Standard Error 0.001 |
| Alcohol Cue Exposure | Alcohol Demand Elasticity | Alcohol Cue Exposure | 0.003 drinks consumed/price (dollars) | Standard Error 0.001 |
Alcohol Demand Intensity
Intensity is defined as the self-consumption in standard drinks at free price. Participants could select between 0-10 standard sized alcohol drinks on the in-scanner alcohol purchase task paradigm. The mean intensity was calculated separately for the two neutral cue runs and the two alcohol cue runs.
Time frame: Collected during each of 4 runs of the FMRI Alcohol Purchase Task. Duration of each run was approximately 6 minutes and included 26 trials.
| Arm | Measure | Group | Value (MEAN) | Dispersion |
|---|---|---|---|---|
| Alcohol Cue Exposure | Alcohol Demand Intensity | Neutral Cue Exposure | 7.42 Drinks | Standard Error 0.3 |
| Alcohol Cue Exposure | Alcohol Demand Intensity | Alcohol Cue Exposure | 7.85 Drinks | Standard Error 0.27 |
Alcohol Demand Omax
Omax is defined as the maximum total expenditure on alcohol for the in-scanner alcohol purchase task. The mean Omax was calculated separately for the two neutral cue runs and the two alcohol cue runs.
Time frame: Collected during each of 4 runs of the FMRI Alcohol Purchase Task. Duration of each run was approximately 6 minutes and included 26 trials.
| Arm | Measure | Group | Value (MEAN) | Dispersion |
|---|---|---|---|---|
| Alcohol Cue Exposure | Alcohol Demand Omax | Neutral Cue Exposure | 49.54 Dollars | Standard Error 6.32 |
| Alcohol Cue Exposure | Alcohol Demand Omax | Alcohol Cue Exposure | 60.63 Dollars | Standard Error 8.39 |
Alcohol Craving
Subjective alcohol craving was assessed using three 100-point scales, including how much they want alcohol, crave alcohol, and their urge for alcohol. A score of 0 indicates the lowest level of craving; a score of 100 indicates the highest amount of craving. The three items were averaged into a composite craving score.
Time frame: Collected immediately after the first neutral cue exposure and immediately after the first alcohol cue exposure.
| Arm | Measure | Group | Value (MEAN) | Dispersion |
|---|---|---|---|---|
| Alcohol Cue Exposure | Alcohol Craving | alcohol cue exposure | 27.99 Points | Standard Error 2.84 |
| Alcohol Cue Exposure | Alcohol Craving | neutral cue exposure | 19.72 Points | Standard Error 2.49 |