Title:
Examining psychometric properties of distress tolerance and its moderation of mindfulness-based relapse prevention effects on alcohol and other drug use outcomes.

Abstract:
Distress tolerance refers to the degree to which an individual is able to withstand negative psychological and/or physical states. Empirical literature has indicated that lower distress tolerance is associated with a number of negative alcohol and other drug (AOD) use outcomes and psychopathology. Mindfulness meditation focuses on enhancing affect regulation, and may be particularly beneficial for individuals with lower distress tolerance. This secondary analysis evaluated the basic psychometric properties of the Distress Tolerance Scale (DTS) in a clinical sample of individuals with AOD-use disorders and tested whether distress tolerance for negative psychological states moderated treatment effects on AOD outcomes in an initial efficacy trial of mindfulness-based relapse prevention (MBRP). It was hypothesized that participants with lower distress tolerance would report fewer AOD use days over the 4-month follow-up if they received MBRP versus treatment as usual (TAU). Participants (N=168) in the parent RCT were recruited from a private, nonprofit agency providing inpatient and outpatient care for individuals with AOD-use disorders. Assessments of 60-day frequency of AOD use, as measured by the Timeline Followback, were conducted at baseline, immediately postintervention, and 2months and 4months following the intervention. Distress tolerance, as measured by the DTS, was assessed at baseline. Results indicated a one-factor solution, which is consistent with how the DTS has been implemented in other studies. As predicted, DTS was positively associated with all mindfulness subscales, suggesting its convergent validity in this clinical sample. Findings showed the hypothesized time×treatment×distress tolerance interaction, and thereby indicated that participants with lower distress tolerance who received MBRP treatment experienced a greater curvilinear decrease in AOD use days over time than those with lower distress tolerance who received TAU. However, the observed plateau effect suggests that these effects were not maintained at the 4-month follow-up. Findings suggest that distress tolerance is a clinically relevant client characteristic to consider in matching participants to aftercare treatment and that MBRP may be particularly helpful for individuals with lower distress tolerance.