Depression since 15 years. Should we do?

My mother used depressed since 15 years she used to meat Dr ravish tunga m glore .she is taking tablets daily but no changes she talks much and she will not sleep properly. she will be exiting always .she is to go out side regurally to other houses by not informing at home she used to talk alone if it is more then if u consult Dr he used give more dosage tablet to her then she will goes on sleeping .then if Dr decrease the tablet then she will be same as back she does it .she will not do work properly and she got memory of past and child hood days but she will not be having memory of present work. even she had prescription from neoralgist Dr shankar before 15 years now she is has sit silently so what should we do