2011 Both My Parents Past Away In 4 Months And

2011 both my parents past away in 4 months and went into grief then suffered possession of spirits and went into psychosis.now i am off them and taking elexipro for 4 years.
What is the long term effect and the risk of fading and there no drug that can defeat a spirit that in your soul that does not want to leave your body even though you pray to have your faith in god and family love ones.