People with Parkinson’s do not use their parasympathetic neurological mode like normal people do. Dominant neurotransmitter in that neurological mode is dopamine. They too often tend to suppress dopamine with adrenaline by using sympathetic neurological mode which is in case of Parkinson’s governed by using dissociation. How to use parasympathetic mode more often? Admit that you are safe after all. Talking to God all the conscious time makes us feel safe and changes our brain biology.