it says in the Bible that God will send them a strong delusion because they loved not the Truth. I know all about it, I had delusions of granduer through schitzophrenia when I was living as a rebel against God. Now I am turning to Christ and He is bringing healing, all thanks and praises to Him and not the pseudo science of Psychaitry which just adds new man made diagnosis to their reference books and doesn't want anyone to truly get better but just make another buck for Big Pharma. Also they are ignorant of the real causes of a lot of mental illness which is demonic in nature and often comes from opening doors into the unseen through wrong religions and occult practises.