Attachment insecurity predicts outcomes in an ACT-CBT group therapy for adults in a physical rehabilitation centre.

Adapting to chronic illness or disability is accompanied by acute and ongoing illness stressors. Psychological factors such as emotional distress and low self-efficacy are common experiences in chronic illness and disability and interfere with adaptation and psychosocial outcomes such as health-related quality of life. Transdiagnostic group psychotherapy may provide a parsimonious approach to psychological treatment in rehabilitation care by targeting shared illness stressors across mixed chronic illnesses and disabilities, and shared processes that maintain psychological symptoms. Attachment theory may explain individual differences in outcomes and help identify individuals at risk of poor health-related quality of life trajectories. Adults (N=109) participated in an 8-week process-based ACT-CBT psychotherapy group at a tertiary care physical rehabilitation centre between 2016 and 2020. Participants completed measures of emotional distress, self-efficacy, health-related quality of life, and attachment at pre- and post-treatment. Multilevel analyses indicated that patients improved on most outcomes at post-treatment. Attachment anxiety at pre-treatment was associated with more positive outcomes. Reliable change indices suggest clinically meaningful change for the majority of participants, but most were not recovered. Results provide proof-of-concept for the transdiagnostic group intervention and suggest that a longer course of treatment may be clinically indicated. Results warrant replication with larger and more diverse samples, and more robust designs.