Subjective responses to simultaneous alcohol and cannabis use relative to alcohol-only use and cannabis-only use: An ecological momentary assessment investigation.

Abstract

Background: Few studies have examined subjective responses to simultaneous alcohol and cannabis use in naturalistic settings. The current study used ecological momentary assessment (EMA) to compare subjective responses between simultaneous use and both alcohol-only use and cannabis-only use sessions, while also examining the moderating role of quantities of alcohol and cannabis consumed at both the session and person levels.

Methods: Young adults (N = 149, 59.73% women) reporting recent simultaneous use completed three 21-day EMA bursts, spaced 6 months apart. Participants completed a survey each time they initiated a new session of alcohol or cannabis use, along with two hourly follow-up surveys. Surveys assessed alcohol use (quantities), cannabis use (quantities, forms of cannabis), and current acute subjective responses.

Results: At the session level, simultaneous use (vs. alcohol-only use) was associated with greater peak sedation and intoxication, with the latter association strengthened during sessions involving relatively lighter drinking. Simultaneous use sessions also involved greater peak liking ratings relative to alcohol-only use sessions, though only among participants who reported relatively lower average alcohol consumption. In addition, relative to cannabis-only use sessions, simultaneous use sessions were associated with greater peak energized and liking ratings, with the former association strengthened during sessions involving relatively heavier cannabis concentrate use. Simultaneous use sessions also involved lower peak sedated and anxious ratings relative to cannabis-only use sessions, though only among participants who reported relatively lighter average cannabis consumption.

Conclusions: Overall, simultaneous use was experienced as more impairing (i.e., greater intoxication and sedation) than alcohol-only use and as more reinforcing (i.e., greater stimulation and liking) than cannabis-only use. Some differences in subjective responses between simultaneous use and single-substance use sessions depended on session-level or person-level consumption amounts, which may inform tailored interventions for simultaneous use.