How is intolerance of uncertainty related to negative affect in individuals with substance use disorders? The role of the inability to control behaviors when experiencing emotional distress.

We used structural equation modeling to assess the role of impaired emotional awareness and clarity (Impaired Awareness/Clarity) and inability to control behaviors when experiencing emotional distress (Inability to Control Behaviors) as an account for the relationship between intolerance of uncertainty (IU) and negative affect (NA) in individuals with Substance Use Disorders (SUDs) and healthy controls (HCs) used for comparison. One-hundred and thirty-one individuals with SUDs (42.75% female; mean age = 39.74 ± 11.83) and 131 sex-matched HCs (mean age = 40.02 ± 12.34) entered the study. Participants completed questionnaires assessing the constructs of interest. Single-group analyses aimed to identify a baseline model for each group and test the hypothesized direct/indirect relations' overall significance. Then, a multigroup analysis tested the invariance of model parameters between SUD and HC groups. The model in which IU had both direct and indirect relationships with NA through Impaired Awareness/Clarity and Inability to Control Behaviors was a good fit to the data. The indirect relationship of IU with NA through Inability to Control Behaviors was significant and moderate-sized. The relationship involving Impaired Awareness/Clarity and Inability to Control Behaviors was small-sized and significant in single group analysis only. The multigroup analysis supported the association of IU with NA through Inability to Control Behaviors in the SUD group. Overall, our study highlights the crucial role of the Inability to Control Behaviors in SUDs and suggests that its association with IU might fuel NA in this population.