Alzheimer’s disease (AD) is an irreversible, progressive neuro-degenerative disorder of the brain that affects various aspects of cognitive functions. It manifests as a progressive impairment of day-to-day functioning, eventually leading to a breakdown of even the simplest abilities. It is the commonest cause of dementia in the world. It is a major cause of disability, dependency and carer stress among older people. It places an immense burden on society and is one of the top 10 causes of mortality worldwide .