This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Organic mental disorders, Subject name: Psychiatry
Most common cause dementia in an adult is 
Select and explain. 
A. Alzheimer's, B. Multi-infarct, C. Pick disease, D. Metabolic cause
A: Alzheimer's
Answer: A: Alzheimer's 
Explanation: 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)