I don't know why some people are relating it to some horror show. It is a psychological show which forces you to give a long thought on couple of things happening in our society. People loves miracles and when they see one or two, they follow that path blindly , if a spiritual path forces you to do some activities which don't make sense.. its better to take a step back and think... In some or the other way we all do some small unnecessary activities in name of God blindly.. the only difference is that this family took it to some other level.... The core of every religion is to do good karmas and be happy with all you got... Which should be enough for your spiritual growth. There is a fine line between faith and delusion.
Secondly, mental health is important , time may heal it but it could also make it worse. Some incidents could impact your brain badly. According to the show's theory, we can see how a person's untreated trauma manipulated a family and is after effects.