Widowed old mother is always mentally torturing me?

I want some more details before i can pinpoint the problem and its cure.First are u working and self independent, are ur sisters married off and they are well off ? is ur mother dependent totally on u or she is getting any sort of pension?Any special reasons why ur father died at that young age?Did he torture ur mother right from day one of their marriage? What could be the cause of her depression? IF u give me the answers then it will be easier for me to pinpoint the problem. She has something very bitter deep in her heart that she is carrying all along which she cant tell u all ( may be about her marriage and what difficulties she had ped through when u were tiny kids, she is yet to come out of the depression) but once she is counselled she will open her heart out. Take her to a good neurologist to get her out of depression (good anti depressant medicines are available)Any way the only solution left is to put her in some old age home ; she will be able to adjust herself with people of her age there. counsellors/ doctors there will counsel her . Make it point to visit her regularly taking turns. I feel most sad for u all ; this is the first case i hear where a mother can ill treat her children without reason.Any way i pray to god to bring a change in her.