Some emotional experiences can alter brain chemistry and/or function. I have a mild PTSD that can get out of hand if I'm not careful to recognize the symptoms when they are coming on.
Here's a little about this condition...
http://krillco.hubpages.com/hub/The-...stry--And-PTSD
Yes, I was in the military. However, the majority of my PTSD came from childhood abuse. My counselor helped bring to light that even my highly emotional and traumatic experiences in church are contributing factors. He has seen people come out of various churches and religions with PTSD.
My counselor has assisted me with Rapid Eye Movement Therapy. It helps.