Frederic, I am not familiar with the thyroid/pd connection, but I am familiar with the psychological/anxiety component. My mom developed this problem to a great extent leading to the introduction of a psychiatrist. The tricky part came about when he began treating the anxiety with drugs, some of which seemed to amplify the bad effects of the PD meds. Consequently, she became over-medicated...her anxiety and hallucinations were undercontrol, but she staggered, slurred her words and was more disoriented than usual. Also, since both she and my step father are afraid of over-medication, they were resistant to each new development and are now REALLY distrustful of any doctors changing meds. So, I don't know if this relates at all to the thyroid question, but the bottom line is caution in the treatment of anxiety. Lynn