The study aims to compare the efficacy of a home-based structured exercise programme (12-step sitting Tai Chi) involving both persons with dementia and their caregivers with a standard non-exercise social contact control in treating depression among caregivers. The effects of exercise on their cognition, quality of life and balance ability are also assessed. We will also examine if BDNF polymorphisms modulate mood changes in response to exercise intervention. Focus groups will be organised at the end to find out the facilitators and barriers in taking up exercise. The findings may offer an avenue of intervention by providing a low cost, relatively safe and effective treatment for dementia caregivers, which may in turn benefit the persons with dementia.

The proposed study is a single-blind randomised controlled trial for two years. We will compare the efficacy of a home-based structured exercise programme (12-step sitting Tai Chi) for both carers and care recipients with a standard non-exercise social contact control in the treatment of depression among caregivers of persons with dementia. The study hypotheses include:

1. The structured home-based exercise programme will reduce caregiver depression. (Primary outcome)
2. The home-based exercise will improve caregivers' cognitive performance, quality of life and balance ability at the end of the study. (Secondary outcome)
3. The home-based exercise will improve the cognitive performance, quality of life and balance ability of persons with dementia at the end of the study. (Secondary outcome)
4. We also hypothesise that BDNF gene modulates mood changes in response to exercise intervention. (Secondary outcome)

Inclusion Criteria:

Caregivers

• 18 years of age and above
• Live with persons with dementia
• 15-item Geriatric Depression Scale (GDS) >0 and <8
• No regular (i.e. ≥ 3 times/week) Tai Chi practice or other forms of mind-body exercise (e.g. yoga, qigong, mindfulness training) in the past six months
• Understand Chinese
• If they are on an antidepressant, they will not be included in the study unless they have been receiving pharmacological treatment on a steady dose for three months

Care recipient

• Aged 60 years or above
• Dementia diagnosis confirmed by a physician
• Dependence in at least one Activities of daily living(ADL)
• Mini Mental State Examination (MMSE) > 10
• No regular (i.e. ≥ 3 times/week) Tai Chi practice or other forms of mind-body exercise (e.g. yoga, qigong, mindfulness training) in the past six months

Exclusion Criteria:

Caregivers

• Presence of psychotic symptoms, imminently suicidal, unstable medical conditions (e.g. recent heart attack, recent stroke, episodes of dizziness, fainting attacks) or significant orthopaedic problems rendering participants unsuitable for physical training
• Carers who are found to have mental conditions that warrants psychiatric assessment and/or treatment (e.g. GDS >8, i.e. local cut-off score for significant depressive symptoms, or suicidal) will be referred to appropriate units for follow up

Care recipient

• Presence of psychotic symptoms, unstable medical conditions (e.g. recent heart attack, recent stroke, episodes of dizziness, fainting attacks) or significant orthopaedic problems rendering participants unsuitable for physical training