Characterizing Proximal Risk for Depressive Symptoms and Suicidal Ideation with Acute Cannabis Use and Withdrawal Among Adolescents Using Ecological Momentary Assessment - PROJECT SUMMARY/ABSTRACT Adolescence is the period of highest risk for the initiation and escalation of cannabis use and emergence of co- morbid psychopathology, including depression and suicidal ideation (SI). Cross-sectional and prospective studies have found that cannabis co-occurs with depression and SI at alarmingly high rates. However, these distal associations do not explain how changes in cannabis use impact intensity and variability in depressive symptoms and SI over shorter, clinically relevant periods of time (e.g., days, weeks, months), including during intoxication and withdrawal. Understanding these proximal relationships will inform the mechanisms that reinforce cannabis use in adolescents at high risk for depression and suicide, yield actionable information about the specific moments during intoxication and withdrawal when a user will be at highest risk for increased intensity and volatility of negative mood and SI, and guide clinical decision-making on the potential therapeutic effect of sustained cannabis abstinence on depression and SI. We propose to conduct a 10-week, multi- method, randomized study, and will recruit 200 school-based adolescents, ages 12-18 years, with daily or near daily cannabis use, current depression, and past month SI. Participants will complete 2 weeks of real-time, ambulatory smartphone monitoring (ecological momentary assessment; EMA) during baseline cannabis use to quantify the temporal relationship between use and mood and SI, and the within-subject (e.g., concurrent other substance use, social context of use) and between-subject (e.g., average severity of cannabis use, depression and SI) factors that may moderate these linkages. To determine how depression and SI change across short- and longer-term cannabis withdrawal, participants will then be randomized to 8 weeks of monitoring (CB-Mon) or abstinence incentivized via contingency management (CB-Abst), and will complete a 1-week phase of EMA at weeks 1 and 8 post-randomization. The overarching aims of this proposal are to test if negative mood and SI are temporarily relieved and stabilized through acute cannabis use (i.e., cycle of negative reinforcement) and to test if negative mood and SI decrease in overall (mean) levels and variability after cannabis wash-out. These aims can be uniquely achieved using EMA via smartphones, which enables high-resolution, within-subjects data collection, thus allowing for elucidation of the specific temporal relationships between cannabis use/intoxication and withdrawal, and depressive symptoms and SI. This will improve on existing data due to its high ecological validity, prospective reporting, and ability to collect dynamic, time-specific changes in the periods immediately before, during, and after acute cannabis intoxication, as well as across the course of withdrawal. Particularly with widespread cannabis legalization, which will likely bring greater drug availability and enhanced societal acceptance, there is a great need to improve our understanding of whether, when, and among whom cannabis use portends heightened risk for psychiatric illness, and depression and suicidal thoughts and behaviors in particular.
