A randomised placebo controlled clinical trial to study the therapeutic effectiveness of a Chinese herbal medicine formula used for the treatment of vascular dementia.

INTERVENTION: Chinese herbal medicine extract prepared in oral capsule form, with a dosage of three capsules daily for 16 weeks. The formulation ingredients remain commercial‐in confidence. CONDITION: Vascular dementia (VaD) PRIMARY OUTCOME: Measuring cognitive abilities using the Alzheimer's Disease Assessment Scale‐cognitive subscale (ADAS‐cog) which is assessed by the trial researchers. SECONDARY OUTCOME: Measuring activities of daily living using the Alzheimer's Disease Co‐operative Study Activities of Daily Living Inventory (ADCS‐ADL), which is administered by the trial researchers. Measuring mental status using the Mini‐Mental Status Examination (MMSE), which is administered by trial researchers. Measuring the overall health of the participant using the Clinician's Interview‐Based Impression of Change Plus Caregiver Input (CIBIC‐Plus), which is assessed by the trial researchers. Short Form Health Survey (SF‐36) assessed by patients and researchers measuring physical and mental health. INCLUSION CRITERIA: 1. A diagnosis of probable or possible Vascular Dementia (VaD) of more than or equal to 3 months in duration based on the NINDS‐AIREN criteria. 2. Hichinski Ischemic Score (HIS) >4 to distinguish VaD from other types of dementia. 3. Absence of severe depression (Geriatric Depression Scale 15‐item version, total score <11). 4. If patients have hypertension, diabetes, cardiac disease, or stroke, these disorders have been stable or controlled by medication for at least 3 months.