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

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.