Apparently the thyroid governs the dopaminergic system. Here is an interesting quote, "Thyroid disease appears to "numb up" the post-synaptic receptors for adrenalin, dopamine, and other neurotransmitters. This is in part why hypothyroidism causes delayed reflexes(doctor's hammer to the knee doesn't cause kick to the .... of the doctor). The nerve signals aren't getting in very well. ," from http://www.thyroid-info.com/articles...depression.htm

The significance of this is that many people are functionally hypothyroid despite normal TSH levels and most doctors don't recognize this fact. It seems that perhaps PD is possibly one of the many conditions caused by or at least exacerbated by poor thyroid function that doctors blame on something else. I wonder how many symptoms could be improved by thyroid treatment.

http://www.youtube.com/watch?v=e9231...feature=relmfu