Investigating Whether Digital Acceptance Commitment Therapy Can Improve Mental Health for Hong Kong Cancer Patients Suffering From Depressive and Anxiety Symptoms.

Digital Acceptance and Commitment Therapy (Digi-ACT): A Randomized Controlled Trial Pilot Assessing the Efficacy and Feasibility of Software-based Self-managed Intervention Targeting Subclinical Depression and Anxiety in Curative Cancer Patients Within Hong Kong

The goal of this clinical trial is to validate the use of digital Acceptance and Commitment Therapy (Digi-ACT) in Hong Kong curative cancer patients with depressive and anxiety symptoms. The main questions it aims to answer are:

• Can Digi-ACT reduce depressive or anxiety symptoms?
• Can Digi-ACT improved health-related quality of life?
• Is Digi-ACT an acceptable and feasible intervention for users?
• What are the factors that influence the success of Digi-ACT?
• Can the video journals used in Digi-ACT predict depressive symptoms?

Intervention group participants will install the Digi-ACT mobile application and undergo a 3-4 week long intervention. They will have to fill out questionnaires at baseline, immediately after the intervention, and at three month follow up to measure depression and anxiety symptoms, health-related quality of life, acceptability of the intervention, and other process outcomes related to the intervention itself.

Researchers will compare the outcomes with a group of participants that undergo a 3-4 week long period where they navigate a similar mobile platform that gives bi-daily psychoeducational videos that also fill out the same clinical questionnaires at baseline, post-intervention, and at three month follow up.

Patients with cancer experience increased rates and severity of depression and anxiety symptoms. This could be due to difficulty dealing with the diagnostic process, treatment side effects, limited social opportunities, physical symptoms, and other cancer-related complications. Acceptance and Commitment Therapy (ACT) has proven to be effective in treating these symptoms for cancer patients. Compared to other evidence based therapies, such as second wave cognitive behavioral therapy (CBT), ACT has shown to have larger effect sizes and success in treating this population. One possible explanation could be due to the theoretical and practical approaches of ACT over traditional CBT. Traditional CBT aims to identify illogical thought patterns that are biased or distorted and try to change them, while ACT makes no attempt at changing these thought patterns and simply teaches the participant to accept and experience these thoughts, emotions, and sensations. For cancer patients, feelings of depression when faced with their own mortality, are unavoidable and could be invalidating if told they are "illogical" or "distorted". Therefore, ACT may have the advantage here in recognizing the severity of the cancer journey and providing an alternative way that does not try to change their experiences.

Furthermore, Hong Kong has a persisting mental health treatment gap due to insufficient mental health practitioners. Oftentimes, only moderate to severe cases of common mental disorders are addressed, thereby leaving milder cases untreated. A possible solution to such under-treatment is digital Health, which requires no additional practitioners and has shown promising results in past studies.

Therefore, we aim to test the efficacy, acceptability, and feasibility of a digitized version (mobile application) of ACT for cancer patients in Hong Kong.

We aim to answer several key questions with the current randomized controlled trial (RCT):

• Can Digi-ACT reduce depressive and anxiety symptoms from baseline to post-treatment and will this reduction be sustained at three month follow up?
• Can Digi-ACT improve health related quality of life from baseline to post-treatment and will this reduction be sustained at three month follow up?
• Is Digi-ACT perceived as an acceptable intervention prior to use? How about after use?
• Can different ACT process measures moderate the relationship between treatment and clinical outcomes?

Research assistants from Hollo will collaborate with Queen Mary Hospital's Oncological unit and Hong Kong Private Clinic: "Oncare" to recruit 50 Cancer patients for the pilot trial within the inclusion criteria. Participants will be screened at baseline for measures of depression and anxiety. Those that score mild or moderate will be invited to participate in the study. Upon providing informed consent, participants will be instructed to download the Hollo Digi-ACT mobile application.

Participants will be randomly allocated to either intervention or active control. Over 4 weeks, participants in the intervention group will be administered the digitized ACT on their mobile device while those in the active control will receive various educational mental health videos over the 4 weeks. After the completion of the intervention, participants will fill out the same clinical indexes and then a final time 3 months later.

Inclusion Criteria:

• Aged 18 and above
• PHQ-9 score of 5 to 14
• BAI score of 8 to 25
• Fluent in Cantonese or Mandarin
• Diagnosed with stage 0 to 3 cancer
• Received surgery as primary treatment at least four months ago

Exclusion Criteria:

• Diagnosed with metastatic cancer (stage 4)
• Language/intellectual difficulties
• Prior diagnoses of other psychiatric conditions other than unipolar depression or anxiety