The effects of cannabis on nicotine use: Integrating human laboratory and ecological momentary assessment methods - PROJECT SUMMARY Co-use of nicotine and cannabis poses a substantial public health risk, including a higher prevalence of health- related, psychiatric, and psychosocial problems, an increased risk for tobacco use disorder (TUD) and cannabis use disorder (CUD), and poorer cessation outcomes for both substances, relative to single-substance use. Over half of young and emerging adults (18-35 years old) who use electronic nicotine delivery systems (ENDS) report using cannabis. Despite the risks and ubiquity of co-use, there is little scientific understanding of how cannabis influences nicotine use. Further, despite well-established sex differences in nicotine and cannabis effects, it is unclear if cannabis differentially affects nicotine use in males and females. The proposed study seeks to fill this gap using a novel combination of human laboratory and ecological momentary assessment (EMA) procedures in young and emerging adults (N=78, 39M, 39F) who use both ENDS and cannabis. First, we will conduct a double-blind, placebo-controlled, within-subject, outpatient design to test the direct effects of vaporized cannabis (0mg,15mg, 35mg D9-tetrahydrocannabinol) on a model of ENDS use behavior. Next, we will examine whether cannabis use acts as a proximal risk factor for naturalistic ENDS use by collecting EMA data for 14 days after the completion of laboratory sessions. Aim 1 of the project will examine how cannabis administration directly impacts ENDS use behavior (i.e., latency, severity), and whether these associations differ by sex, Aim 2 will examine whether cannabis use is associated with naturalistic ENDS use behavior, and whether these associations differ by sex, and Aim 3 will examine whether ENDS use behavior following cannabis administration under controlled laboratory conditions is associated with ENDS use following cannabis use in daily life. This novel, multimodal assessment will identify if and how cannabis interacts with nicotine to influence nicotine use and will thereby help to inform the development of tailored intervention approaches to decrease the public health burden of TUD. The proposal will also train the PI on how to conduct rigorous, placebo-controlled human laboratory studies that she can integrate with her existing expertise in EMA, supporting her long-term goal of becoming an independent substance use researcher.
