Yes...Bully syndrome who was always full of fear and became exposed when the feared leaked out. Never to be the same.
That is a popular theory that has been advanced by Teddy Atlas and sportwriters trying to create a narrative.
I believe the truth is that by 1990 Tyson had lost Robin Givens, fired his trainer and managers, gotten involved with Don King, was bored with fighting, didn't want to get in shape, was surrounded by leeches and yes-men and would rather just bang groupies and spend his enormous fortune.
He was no longer physically or mentally at his best. It was still difficult for people to beat him until much later when he was getting close to 40 years old.