ACT for Dementia Caregivers: Evaluating Psychological Flexibility as the Mechanism to Improve Psychological Distress

Over 55 million people worldwide have dementia, and in the United States, 80% of people with dementia are cared for at home by family. While family caregivers report positive aspects of their role, many report depressive and anxiety symptoms, and global distress. There is vast heterogeneity in caregivers' experiences, dependent on biopsychosocial risk/contextual factors, and secondary challenges (financial concerns, work disturbances, etc.). While an array of empirically validated interventions can support dementia caregivers, interventions utilizing a transdiagnostic approach can yield improvements in comorbid symptomatology by addressing common underlying mechanisms of chronic or acute conditions, and mechanisms that promote living well with stress.

Acceptance and Commitment Therapy (ACT) is a modern ("third wave") Cognitive Behavioral Therapy (CBT) that addresses clinically significant, or subclinical levels of anxiety, depression, and a myriad of other conditions. The transdiagnostic mechanism in ACT involves increasing psychological flexibility, by changing the impact of negative thoughts and feelings, without having to change the frequency or form of their occurrence. ACT teaches individuals how to engage with painful/stressful experiences and respond with behaviors aligned with their personal values. Across 20 meta-analyses (n=12,477) of ACT clinical trials, ACT is efficacious in improving depression, anxiety, distress, and more. In dementia caregivers, therapist-guided ACT has also yielded improvements in various aspects of psychological distress.

Despite the evidence for ACT improving dementia caregivers' mental health, therapist-delivered interventions are more costly, less convenient, and less "scalable" (i.e. reaching fewer individuals). Online self-guided therapies can be equally effective as face-to-face therapy and are effective for caregivers. In non-caregivers, ACT has been adapted to online, self-guided delivery, demonstrating effective therapeutic results. The investigators' preliminary (Stage I and II) studies provide evidence that ACT is feasible and acceptable in an online, self-guided program tailored to dementia caregivers, and have identified preliminary efficacy in improving the proposed mechanism of change, psychological flexibility, and outcomes of caregiver depression. There is, however, a substantial need to understand if/how psychological flexibility and engagement with ACT for Caregivers work mechanistically to reduce psychological distress for users (with distress defined by the DASS-21 as symptoms of depression, anxiety, and stress). This proposal is responding to the EMBRACE call for mechanism-focused dementia care and caregiver support intervention development, targeting the level of the caregiver. Guided by the Checklist for Investigating Mechanisms in Behavior-change Research (CLIMBR), this Stage II (N=120) waitlist randomized control trial (RCT) will:

1. Determine the efficacy of an online, self-guided ACT for Caregivers program for improving dementia caregiver psychological distress. The investigators hypothesize that treatment-to-waitlist condition will be associated with reductions in psychological distress over time, pre-to-post intervention, where those in the treatment group will show greater improvements in distress compared to those in the waitlist condition. 2. Determine if and how treatment effects explain changes in psychological flexibility and how changes to psychological flexibility account for changes in distress. The investigators hypothesize that caregivers in the treatment group will show improvements in psychological flexibility, above and beyond, those in the control group. Further, the investigators hypothesize that these changes to psychological flexibility will account for changes in distress. 3. Determine if and how user adherence to the program at time 2 (i.e., number of online sessions completed) is associated with the proposed mechanism, psychological flexibility (at time 3). The investigators hypothesize that, within the treatment group, greater adherence to ACT modules will be associated with greater psychological flexibility and greater improvements in distress.

With this Stage II study, the investigators examine if the proposed mechanism of change in ACT for Caregivers -- psychological flexibility -- influences changes in caregivers' distress. The investigators also explore how user adherence to the program is associated with changes in both the mediator and the outcome. Gathering evidence on the mechanism of change and intervention adherence is a necessary step in establishing ACT for Caregivers as an empirically validated intervention for dementia caregivers.