When he was really little, my oldest son was prone to having tantrums. When he was four years old, he was literally hopping mad one day and this resulted in him literally bursting a blood vessel. He developed a sudden, really severe nosebleed. He was prone to nosebleeds anyway, but this was one of the worst ones he ever had and I was concerned for a bit that I would need to take him to the ER because I had trouble getting it to stop, in spite of experience and knowledge about this issue.
The experience was incredibly shocking for him. The idea that his feelings could actually cause him direct physical harm really freaked him out. Furthermore, the event caused his tantrum to end very suddenly. The tantrum came to a screeching halt, so to speak. Without any training, he was able to use this experience as a form of biofeedback. He had felt something in his brain when it stopped and that allowed him to find some means to interrupt the runaway process at subsequent events.
He didn't like being mad, so being mad made him mad about the fact that he was mad and it created a positive feedback look that caused his anger to just go off the rails. He stopped having tantrums following this incident.
I think, yes, psychological things can literally have direct physical impact. We know it can do things like raise your blood pressure. This is an ordinary thing. With extreme enough experiences, I see no reason why it wouldn't impact the brain in a meaningful way with long term consequences