(PS7-C64) The Impact of the Six Core ACT Processes on Treatment Outcomes in Intensive Exposure Therapy for OCD

Background:  Exposure and response prevention (ERP) is considered the gold-standard treatment for obsessive-compulsive disorder (OCD). However, many individuals with OCD do not fully respond to this treatment. Based on emerging research implementing ERP from an Acceptance and Commitment Therapy (ACT) framework (Twohig et al., 2015), this study sought to explore how changes in the six core ACT processes influence ERP outcomes throughout treatment in a naturalistic intensive/residential treatment program.

Methods:  Participants (N = 280) with OCD and related disorders (mean Y-BOCS scores ranging from severe to extreme) provided daily ratings of their engagement with the six core ACT processes underlying the Hexaflex model of psychological flexibility (Hayes, Strosahl & Wilson, 1999, 2011). Obsessive–compulsive and depressive symptom severity as well as quality of life ratings were also assessed weekly. Linear mixed-effects modeling was used to assess the impact of engagement with these ACT processes on treatment outcomes across each week of treatment.

Results:  With the exception of values (B = -.031, p = .12), higher engagement with each of the ACT processes was significantly associated with lower Y-BOCS scores, including acceptance (B = -.034, p < .001), cognitive defusion (B = -.022, p < .001), present-moment awareness (B = -.033, p < .001), self-as-context (B = -.023, p < .001), and committed action (B = -.035, p = .001). Similarly, higher engagement with all six ACT processes was significantly associated with lower HAMD scores, including acceptance (B = -.021, p < .05), cognitive defusion (B = -.014, p < .05), values (B = -.020, p < .05), present-moment awareness (B = -.030, p < .001), self-as-context (B = -.021, p < .001), and committed action (B = -.030, p < .05). Finally, greater engagement with present-moment awareness (B = .031, p < .05) and self-as-context (B = .017, p < .05) were significantly associated with higher quality of life ratings (QLES).

Conclusions: Engaging with ACT processes during exposures appears to result in successful treatment outcomes as evidenced by significant changes in patients’ ratings on not only symptom specific measures (i.e., Y-BOCS, HAMD) but also on more global measures of wellbeing and functioning (i.e., QLES). These findings suggest the potential benefit of targeting ACT-related mechanisms of change in ERP and suggest further research examining the role of both ACT processes and ACT-related outcomes in OCD treatment.