Welcome to Healthcare Magic and thanks for your question...
Firstly, I would like to make a correction... I think you mean that your wife is having a mental health problem, and not 'mentally retarded'. You have mentioned that her psychological problems started after her 2nd delivery. Now, nearly half the mothers can develop mild emotional changes and problems following delivery, which are temporary and self-limiting. But a small percentage of them can go on to develop more serious and persistent problems which require treatment. I think your wife may be suffering from a post-partum depression
Having false beliefs, unrealistic fears and suspicions may be indicative of a post-partum psychosis. Moreover, she has also had to deal with a major stressor due to the death of your mother, which may have been a precipitating factor for developing her psychiatric problem. It is good that you have taken her to a psychiatrist
for help. However, it is also very important to continue medication regularly, because it is both essential for recovery and for preventing relapse of symptoms.
I think you should take up the responsibility of ensuring that she takes medication everyday, because when people are going through psychiatric problems, they often don't feel that medication is necessary or going to help them. If she is refusing medication completely or being very unco-operative, then you should discuss further options with your psychiatrist.
All the best.
- Dr. Jonas Sundarakumar