Project Summary
Simultaneous use of alcohol and marijuana/cannabis (SAM) leads to increased craving, use, and
consequences compared to single use of either alcohol or cannabis. However, there is a dearth of knowledge
regarding the neural, neuroendocrine, and behavioral differences in SAM users that increases risk for these
negative outcomes. The current proposal aims to address this significant gap in knowledge by examining how
stress related neural and neuroendocrine processes may differ in SAM users relative to single substance users
or a control group. A sex-balanced sample of four hundred forty male and female individuals reporting SAM
use, alcohol use only, cannabis use only, or neither binge/heavy alcohol use nor cannabis use will be recruited
to complete a neuroimaging session and three 14-day bursts of ecological momentary assessment (EMA) over
the course of one year. During the neuroimaging session, participants will complete a stress cue reactivity task
while undergoing fMRI and will also have blood drawn to assess stress-induced cortisol response. Participants
will complete a baseline EMA burst that focuses on daily experiences of stress, craving and drug use, and will
complete follow-up bursts at 6- and 12-months post-baseline. This proposal aims to better understand how
stress processes are related to increased risk among SAM users. Specifically this proposal will investigate 1)
how neural and neuroendocrine responses to stress are moderated by group (i.e., SAM, alcohol-only,
cannabis-only, control), sex, and the interaction of group x sex; 2) how group, sex, and group x sex
interactions, and neural/ neuroendocrine responses moderate the momentary relationships between stress and
craving/use in daily life; and 3) how group, sex, and group x sex interactions, and neural/neuroendocrine
responses moderate the trajectory of craving/use over a one-year follow-up period. Broadly, we expect that
while single substance users will have some dysregulation, SAM users will exhibit the greatest stress
dysregulation relative to controls, and females (vs. males) will demonstrate greater dysregulation of
neural/neuroendocrine responses to stress, greater momentary relationships between stress and craving/use,
and steeper trajectories of craving/use. Successful completion of these aims will significantly advance our
understanding of the mechanisms by which SAM use increase risk for substance use disorders and other
negative outcomes, which will be key in guiding future intervention and prevention efforts.