HIGHS AND LOWS: PSYCHOLOGICAL FLEXIBILITY AS AN EXPLANATION FOR THE CANNABIS USE-MENTAL HEALTH RELATIONSHIP

Background: Cannabis use (CU) has rapidly grown worldwide.Cannabis use disorder (CUD) is associated with a three-fold increase in internalizing disorders such as depression and anxiety.Psychological flexibility (PF) encompasses an individual's ability to be open and accepting of emotional experiences (openness to experience; OE), and to adjust their behaviours (behavioural awareness; BA) to be in line with their personal values (valued action; VA).PF can be targeted and improved through Acceptance and Commitment Therapy (ACT), which has been shown to be effective for addressing depression and anxiety symptoms; however, the role of PF in substance use is less explored and mechanisms underlying the comorbidity remain unclear.Rationale: The aim of this study was to examine the mediating role of PF in the relationship between CU patterns (i.e., daily use, disordered use), and internalizing symptoms.Method: Individuals from an Atlantic Canadian University, the general population, and Prolific (N = 525) completed measures assessing CU patterns (meeting criteria for DSM-5 CUD, daily use), anxiety and depressive symptoms, and PF.Results: Daily CU was positively associated with depressive and anxiety symptoms.CUD symptoms were also positively associated with depressive and anxiety symptoms.Daily CU was negatively associated with PF total and with two PF dimensions (OE, BA).As expected, CUD symptoms were negatively associated with PF and with all three PF dimensions.Six mediation models were tested, with daily CU/CUD symptoms entered as independent variables, depression and anxiety as the dependent variables, and total PF or its dimensions as mediators.The three dimensions of PF (OE, BA, VA), and PF total partially explained the relationship between CUD symptoms, and both depressive and anxiety symptoms.The same was found for the relationship between daily CU and depression but only the dimensions of OE and BA mediated the relationship between daily cannabis use and anxiety symptoms.Conclusions/Impact: Problematic cannabis users appear lower in PF, which may partly explain why they experience more internalizing symptoms.Interventions aiming to increase PF, such as ACT, may be appropriate for such individuals.