<prompt> Most common cause dementia in an adult isAlzheimersMulti-infarctPick diseaseMetabolic cause  <response>: Dementia is a chronic organic mental disorder characterised by impairment of intellectual function, impairment of memory, deterioration of personality with lack of personal care Alzheimer;s is the commonest cause of dementia seen in about 70 of all cases of dementia in USA. It is more commonly seen in women Ref: a sho textbook of psychiatry, Niraj Ahuja,7th edition, pg no23 