Introduction: People with dementia have a high prevalence of psychological distress but are under-served with evidence-based psychological interventions. To promote choice and improve clinical outcomes, there is a necessity to test different psychological intervention options for this population. Purpose: To investigate the effectiveness and acceptability of Acceptance and Commitment Therapy (ACT) for people with dementia, considering carer-supported, remote delivery and necessary therapy adaptations. Methods: A hermeneutic single case efficacy design (HSCED) series was used to analyse therapy process and change for three clients with dementia and psychological distress. Quantitative and qualitative data was collated ('rich case records') and analysed by three independent psychotherapy experts ('judges') who determined the outcome for each client. Results: Over the course of therapy, it was concluded that one client with dementia made positive changes, specifically reliable reductions in psychological distress, which were largely attributable to Acceptance and Commitment Therapy (ACT). Two clients remained unchanged. Discussion/Conclusion: Where change was achieved, the ACT-specific processes of values, committed action and acceptance, in combination with non-specific therapy factors including a strong client-carer relationship, existing client interests and individualised therapy adaptations, were facilitative of change. Hence, ACT may be feasible and effective by helping carers to better meet the needs of their loved ones with dementia. Future research to optimise ACT delivery in this population may be beneficial. Furthermore, the assessment of carer factors (e.g., their psychological flexibility, the client-carer relationship) may strengthen the evidence-base for systemic ACT-use.

Inclusion Criteria:

Inclusion criteria for people with dementia

Participants were included in the study if they had:

• A clinical diagnosis of dementia (any type)
• A clinically significant level of psychological distress (a score of ≥8 on the GAD-7 and ≥10 on the PHQ-9).
• Ability to give informed consent

Inclusion criteria for caregiver of person with dementia

Participants were included in the study if they:

• Cared for someone with a clinical diagnosis of dementia (any type)
• Were paid or unpaid and regularly supported them with activities of daily living
• Aged 18+ (no maximum age limit)
• Able to give informed consent

Exclusion Criteria:

Exclusion criteria for people with dementia

Participants were excluded if they:

• Were already receiving psychotherapy
• Had insufficient English or language abilities to engage in therapy
• Were unable to consent to and/or engage in therapy

Exclusion criteria for caregiver of person with dementia

Participants were excluded if they:

• Had insufficient English or language abilities to support the person with dementia or engage in study/Change Interviews
• Were unable to consent to and/or engage in study

The study data was written up as part of the student Doctoral Thesis and will be submitted in partial fulfilment of the requirements for the Trent Doctorate in Clinical Psychology (DClinPsy) in February 2022.

Participants chose a pseudonym for themselves to be used in publications (e.g. electronic documents, written notes and transcripts) to prevent identification and references to personal information (e.g. other people's names, locations) were altered.

July 2022