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

Area of Science:

• Addiction research
• Psychopharmacology
• Behavioral science

Background:

• Simultaneous alcohol and cannabis use is linked to adverse outcomes.
• Motivations for combined substance use, particularly early subjective effects, are poorly understood.
• Early substance experiences may drive complementary or replacement use patterns.

Purpose of the Study:

• To investigate whether subjective effects of initial alcohol or cannabis use predict the likelihood of simultaneous use.
• To examine if the order of substance administration moderates the influence of subjective effects on combined use decisions.

Main Methods:

• A hypothetical decision-making task was administered to 486 college students.
• Participants rated their likelihood of simultaneous use across eight scenarios varying in alcohol/cannabis subjective effects (positive/negative, high/low arousal).
• Multilevel modeling analyzed the relationship between subjective effects, substance order, and simultaneous use likelihood.

Main Results:

• Task-based simultaneous use likelihood correlated with self-reported combined use, validating the task.
• Positive subjective effects (high/low arousal) increased the likelihood of simultaneous use.
• Negative subjective effects (high/low arousal) decreased the likelihood of simultaneous use.
• Substance order significantly moderated the effects of certain subjective experiences on simultaneous use decisions.

Conclusions:

• Early subjective effects of alcohol and cannabis are significant predictors of simultaneous use.
• Interventions targeting the sequence and subjective nature of substance use experiences may help reduce combined use.
• Findings highlight the importance of event-level factors in understanding polysubstance use patterns.