Between- and Within-Person Effects of Alcohol and Cannabis Co-Use on Subjective Alcohol Response and Problem Drinking - Project Abstract:
The proposed fellowship seeks to identify whether subjective alcohol response (i.e., acute affective and
intoxicating effects) serve as both between-person and within-person mechanisms of risk through which
alcohol and cannabis co-use is related to heavier drinking and negative consequences. The applicant's long-
term career goal is to obtain a tenure-track faculty position with a research program focused on the dynamic
interplay among co-use, subjective response, and impulsivity as predictors of problem drinking. This fellowship
will enable the applicant to gain expertise in subjective response to co-use, advanced quantitative analyses, as
well as Ecological Momentary Assessment (EMA) data management and organization. This fellowship will also
enable the applicant to develop and strengthen fruitful collaborations with leaders in the field of co-use,
subjective response, and EMA methods. The current training plan features a highly skilled mentoring team with
expertise in subjective alcohol response (Dr. William Corbin), advanced quantitative analyses (Dr. Kevin
Grimm), subjective response to cannabis/co-use (Dr. Jane Metrik), and EMA methods of co-use (Drs. Christine
Lee and Timothy Trull). The proposed project will use data from an ongoing EMA study that captures event-
level data on subjective response to moments of co-use (vs. alcohol-only use), as well as same-night drinking
quantity and negative consequences via a novel phone application (TigerAware). The proposed study will test
1) whether co-users (vs. alcohol-only users) endorse heightened between-person levels of subjective response
(i.e., acute affective and intoxicating effects), 2) whether event-level co-use (vs. alcohol-only use) is associated
with heightened within-person levels of subjective response, and 3) whether subjective response mediates the
within-person effect of event-level co-use (vs alcohol-only use) on heavier drinking and negative consequences
aggregated to the day-level. Participants (Current N=115; Target N=130) will come from a 21-day EMA study,
in which they were asked to fill out a morning report, two afternoon reports, and three nightly reports.
Participants were asked to initiate a drink report when drinking, which had follow-up assessments that replaced
concurrent random reports at that time. Co-use of alcohol and cannabis was assessed during drink reports,
acute subjective response was assessed during drink reports, and past-night drinking quantity and negative
consequences were assessed during next-day morning reports. The proposed study will be the first to test both
between-person and within-person differences in subjective response based upon co-use. It will also be the
first to differentiate co-use “subjective intoxication” from several subjective response domains, which is vital to
understand which acute effects are enhanced or exacerbated by co-use. Findings will inform brief interventions
by better understanding 1) between-person risk factors for alcohol misuse to tailor via broad-level
interventions, and 2) within-person risk factors to target via just-in-time interventions seeking to reduce alcohol
misuse on riskier (i.e., co-use) days.
