What Role Does Cannabis Use Have in Anxiety? The Moderating Effect of Sensitivity to Unpredictable Threat

It is critical to understand the comorbidity between anxiety disorders (ADs) and cannabis use disorder (CUD) as this comorbidity is associated with costly social and economic consequences. Ecological momentary assessment (EMA) is a method that can help elucidate the temporal relationship between anxiety and cannabis use as it captures subtle variations in mood and behavior as they occur. Prior EMA studies largely focused on the relationship between broad negative affect and cannabis use and have rarely investigated the potential separable and independent effects of state anxiety and state sadness. The handful of EMA studies focused on anxiety and cannabis use have been mixed, however, and had several important limitations. Moreover, there are likely specific individual difference factors that impact the association between anxiety and cannabis use. Heightened sensitivity to unpredictable threat (SUT) is one such individual difference factor as it connotes vulnerability for ADs and is also likely to play a role in cannabis use. The present study therefore tested (1) the directional relationship between cannabis use and anxiety, (2) whether trait SUT moderates the temporal relationships between state anxiety and cannabis use, and (3) whether these relationships are independent of state sadness in a community sample of 34 moderate cannabis users (1 - 5 cannabis use days per week) over a 2-week EMA period consisting of both signal and event contingent assessments. Results indicated that momentary state anxiety predicted increased likelihood of subsequent cannabis use, but not after accounting for momentary state sadness. Cannabis use predicted reductions in subsequent state anxiety independent of momentary state sadness, tobacco use, and alcohol use. For those high in SUT, momentary state anxiety predicted increased likelihood of subsequent cannabis use and momentary cannabis use predicted reductions in subsequent state anxiety independent of momentary state sadness, tobacco use, and alcohol use. In sum, anxiety may temporally precede cannabis use and the anxiolytic effects of cannabis use may negatively reinforce further use, especially for those high in trait SUT. Existing AD treatments may therefore benefit by targeting the mechanisms underlying SUT to prevent onset of CUD.