Hello. Firstly if you ar stalking about your mental illness, it can occur in the offspring however the chances are very less and vary according to the illness. Secondly if you are talking about medicines, then lithium and even olanzapine to certain extent can cause some congenital defect in the offspring. However the risk is highest only during the first 3 months of pregnancy. In the laster 6 months they are less likely to cause any defect in the offspring. The risk must be weighed against their benefits. I would advise consulting your Psychiatrist before conceiving or planning conception.

Yes it is possible because these diseases do have genetic predisposition and can be transferred to your off springs