Inclusion Criteria: a diagnosis of dementia consistent with Diagnostic and Statistical Manual of Mental Health Disorders, revised 3rd edition (DSM-III-R) (APA, 1987) National Institute of Neurological and Communicative Disorders and Stroke - Alzheimer's Disease and Related Disorders Association (NINCDS-ADRDA) diagnostic criteria for probably or possible AD (MKhann et al, 1984) (Appendix 6) clinically significant agitation (defined as causing distress to patient and at least moderate management problems for carers on at least two days per week for a two week period, together with a Cohen Mansfield Agitation Inventory (CMAI) (Cohen-Mansfield, 1986) (Appendix 11 A) score >39 age >39 years resident in care facility or community living with a carer not receiving treatment with neuroleptics or cholinesterase inhibitors currently or in the past four weeks and responsible clinician not considering treatment with cholinesterase inhibitor for the next 16 weeks taking into account the clinical evidence base and NICE guideline (NICE, 2001) patient with capacity willing to consent to study or will to participate in study if lacking capacity carer with capacity willing to consent to study and in agreement for patient lacking capacity to participate if patient willing to participate