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Multiple Therapeutic Mechanisms of an Automated Self-Guided AI-Enhanced Psychoeducation Intervention for Dementia
Sheung-Tak Cheng1, Peter H F Ng2
1Department of Health and Physical Education (Cheng), The Education University of Hong Kong, Tai Po, Hong Kong.
Objective:
PDC30, an online psychoeducational intervention, was found to improve depression, burden, and positive gains in dementia family caregivers, compared with a 1-month waitlist control. However, the therapeutic mechanism is unclear. This study investigated whether caregiving self-efficacy and positive reappraisal coping mediated the intervention effects.
Design:
Longitudinal mediation within a parallel-group randomized waitlist-controlled trial.
Setting:
Web-based platform accessible 24/7 globally.
Participants:
From 43 countries, 274 caregivers who provided ≥10 weekly care hours to relatives with dementia, scored ≥5 on Patient Health Questionnaire-9 (PHQ-9), and were without recent intervention.
Intervention:
A self-guided automated intervention, PDC30 combines a Guidebook, a graphic novel (for caregivers with children), an AI-powered counseling chatbot, and interactive tools to support cognitive-behavioral strategies, relaxation practices, and activities that strengthen caregiver-recipient relationships.
Measurements:
The primary outcome was depression (PHQ-9), and secondary outcomes were burden and positive gains. Mediators were self-efficacy beliefs (responding to disruptive behaviors [SE-RDB] and controlling upsetting thoughts [SE-CUT]) and reappraisal coping. Following baseline measurement, mediating and outcome variables were re-assessed at 3 weeks and 1 month respectively. Missing values were replaced by multiple imputation.
Results:
Path model estimated using restricted maximum likelihood showed that improvement in depression was mediated by SE-CUT (indirect effect β = -0.033) and reappraisal coping (β = -0.043); burden reduction by SE-CUT (β = -0.037) and SE-RDB (β = -0.041); and positive gains increase by reappraisal coping (β = 0.048).
Conclusions:
While SE-RDB was partly responsible for PDC30's effect on burden, the main drivers of the impacts on mood, positive gains, and burden, were increased reappraisal coping and SE-CUT.
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