I again thank you schwad01, I read the above with my mind racing as my particular interest is stress as a causative factor in PD for some of us. I keep going back to a piece released last year which announced that a team from Uppsala Uni in Sweden had found using the latest scanning tech that px's diagnosed with anxiety had elevated levels of serotonin not reduced.
This could explain why some folk get a lot worse on SSRI's. I have made 3 attempts to benefit from antidepressants and each time ended up with what appeared to be like serotonin syndrome, restless,dizzy,fluctuating bp and pulse etc.
I wonder if one of the 5-htp types when working overtime has an inhibitory effect on dopamine production.
So now after reading about the 'second brain' I know that most of the body's serotonin is in the gut.....and the connection of anxiety with the gut...and also this PD/gut connection, I guess I'v got another early hours project.