This study will evaluate the effectiveness of a structured acceptance-based diabetes education programme for adults with type 2 diabetes compared with those who received diabetes education. The programme mainly comprises acceptance and commitment therapy (ACT) as a psychological component and a diabetes education (DE) component. The short form of the programme is named 'ACT-DE'. This programme aims to decrease the diabetes distress level in participants with type 2 diabetes and improve their blood glucose level. The objectives are:

1. To develop an ACT-based intervention protocol as a guide for promoting healthy coping in people with type 2 diabetes who are psychologically distressed.
2. To examine the effects of 'ACT-DE' on diabetes distress and HbA1c (primary outcomes) over a three-month follow-up, when compared with diabetes education only.
3. To examine the effects of 'ACT-DE' on diabetes self-management behaviours, self-efficacy in diabetes care, and psychological flexibility (secondary outcomes) over the three-month follow-up, when compared with diabetes education; and
4. To identify the relationships between psychological flexibility and diabetes self-efficacy, diabetes self-management behaviour and HbA1c among the study participants

Diabetes distress is an aversive feeling and emotional disturbance specific to diabetes, including the burden of daily self-care, worry and guilty feelings, and low satisfaction level with health care professionals. Around 36% of people with type 2 diabetes worldwide suffered from diabetes distress, which is associated with poor self-care performance, low self-efficacy in diabetes management and higher blood glucose levels. Acceptance and commitment therapy, one of the mindfulness and acceptance-based interventions, integrated with diabetes education are found to be potentially effective interventions for reducing diabetes distress.

A pilot study has been conducted earlier (NCT05563987) and showed that a six-week ACT-DE programme (5 sessions) was preliminary effective compared to attending only one session of diabetes education. It was also a feasible and acceptable intervention.

In this main study, a convenience sampling method will be adopted from three out-patient clinics of public hospitals in Hong Kong. A total of 176 eligible participants will be randomly allocated into the intervention (N=88) and the control group (N=88). Participants in the intervention group will receive 6-week ACT-DE programme (5 sessions) composing acceptance and commitment therapy and diabetes education. Each session last for 120 minutes in a group of 8-10 participants. Participants in the control group will receive one session of diabetes education.

Inclusion Criteria:

• community-dwelling adults Hong Kong Chinese residents,
• aged 18-64,
• diagnosed with type 2 diabetes for over one year;
• at least moderate level of diabetes distress as measured with the Chinese
• Diabetes Distress Scale (CDDS-15; mean score >2 per item);
• having suboptimal blood glucose control as shown by HbA1c level of ≥ 7% in the laboratory results within the past six months;
• able to communicate in Cantonese and give written consent

Exclusion Criteria:

• history of a clinically diagnosed mental illness such as depression and anxiety disorder, and/or an acute/severe medical disease;
• noticeable cognitive impairment(s) as indicated by the total score (<6 of 10) of the Abbreviated Mental Test;
• recently received/receiving any psychological therapy such as mindfulness or acceptance-based therapy.

The outcome assessor who is responsible for collecting outcome data and data entry has no idea about the group allocation or participants.