dementia and will

 The mere prescription is not enough to invalidate the Will. This can be taken as a piece of corroborative evidence. In case the doctor who treated or who is the author of the prescription is examined, then it will have some weigtage. 

For a will to be valid it should have been authored by the testator during the state of sound mind and in full conscience and without any duress, coercion, threat, or undue influence and should have appended his signature on such testament knowing fully the facts stated in the testamentary document in the presence of at least two independent witnesses who should have seen the testator append his signature to the document knowing fully what he is doing.

In view of the above, in the present case if it can be proved that the will has been made by the testator during sound state of mind supported by the evidence of atleast one attesting witness, the will can be treated as a valid one.

Prakash, what would be doctor examined for? He can just say yes it is my writing and signature. Because patient is not alive, so recognizing the patient is out of question. It was a government hospital and doctors attend so many patients there, its very unlikely that doctor can remember the patients features or out look.