A hypothetical lottery task to assess relative resource allocation toward alcohol and cannabis

Do Subjective Effects from Alcohol and Cannabis Predict Simultaneous Use During a Decision-Making Task?

Background: Simultaneous alcohol and cannabis use is associated with negative outcomes, yet little is known about what motivates the decision of simultaneous use. One possibility is that early-episode subjective effects motivate simultaneous use to complement or replace the first substance's effects. The current study used a hypothetical decision-making task to test this hypothesis. Objectives: College students (N = 486) were presented eight scenarios characterized by alcohol/cannabis subjective effects (i.e., high/low arousal positive [e.g., excited, relaxed], high/low arousal negative [e.g., aggressive, dizzy]) and asked their likelihood of simultaneously using the other substance per scenario. Multilevel modeling tested whether subjective effect scenarios predicted a higher likelihood of simultaneous use and whether ordering moderated this association. Results: Task-based simultaneous use likelihood was associated with self-reported simultaneous use, showing task validity. Scenarios characterized by high/low arousal positive effects were associated with higher likelihood of simultaneous use, whereas high/low arousal negative scenarios were associated with lower likelihood. Alcohol vs. cannabis-first scenarios were associated with higher likelihood of simultaneous use, and significant interactions were observed for high/low arousal positive and high arousal negative effects. High arousal positive scenarios were associated with higher likelihood of simultaneous use when cannabis was used first, low arousal positive scenarios with higher likelihood when alcohol was used first, and high arousal negative scenarios with lower likelihood when cannabis was used first. Conclusions: Beginning-of-episode subjective substance effects may be a promising event-level predictor of simultaneous use, and just-in-time interventions may benefit from targeting the ordering and subjective experiences of alcohol and cannabis use.

Use of preexposure prophylaxis and condom purchasing decisions

Preexposure prophylaxis (PrEP) prevents human immunodeficiency virus (HIV) but not other sexually transmitted infections (STIs). Men who have sex with men (MSM) who take PrEP tend to report reduced condom use, but little is known about the underlying mechanisms. For this study, MSM who take PrEP (i.e., PrEP experienced; n = 88) and MSM who do not (i.e., PrEP naïve; n = 113) completed an online study, including the condom purchase task (CoPT). The CoPT assesses decisions to purchase condoms across escalating prices (range: free-$55) for sex with different types of hypothetical partners: those least likely to have an STD (least STD) and those that participants most want to have sex with (most want sex with). When condoms were free, PrEP-experienced MSM had a lower rate of condom purchasing than did PrEP-naïve MSM. For both partner types, PrEP-experienced MSM reached a price break point (i.e., would not buy condoms) at a lower price than did PrEP-naïve pariticipants. For the most-want-sex-with partner at the price at which participants elected not to buy condoms, only 23% of PrEP-experienced MSM chose to abstain from sex when not purchasing condoms versus 53% among PrEP-naïve MSM. Similar patterns were observed for the least-STD partner. The results support the potential utility of the CoPT in identifying behavioral mechanisms related to condom use and PrEP.

A hypothetical lottery task to assess relative resource allocation toward alcohol and cannabis

OBJECTIVE

Relative spending on substances (vs. alternatives) is predictive of several substance use outcomes, but it can be challenging to assess. We examined a novel method of assessing relative resource allocation through the use of a hypothetical lottery task wherein participants assume they collected $100,000 United States dollars in lottery winnings and were tasked with allocating their winnings across spending categories (e.g., savings, leisure, alcohol, cannabis). We hypothesized relative allocation of funds toward alcohol and cannabis would be positively associated with more use and problems of each substance.

METHOD

College students (N = 479; Mage = 19.9 [SD = 2.2]) reported on their substance use and problems, alcohol and cannabis demand, and the hypothetical lottery task.

RESULTS

Relative resource allocation toward alcohol and cannabis on the lottery task positively correlated with alcohol and cannabis demand indices (intensity, breakpoint, Omax, and elasticity [negatively]), respectively. Using zero-inflated modeling, greater relative allocation toward alcohol positively related to alcohol use and problems in models that controlled for alcohol demand indices. For cannabis, relative resource allocation was also positively associated with cannabis use, but not problems, independently from cannabis demand indices.

CONCLUSIONS

Results provide initial support for the hypothetical lottery task as an indicator of relative resource allocation toward substances. Generally, these results extend previous behavioral economic research demonstrating the utility of relative resource allocation as a unique predictor of clinically relevant outcomes. (PsycInfo Database Record (c) 2023 APA, all rights reserved).