"Depletion of nigrostriatal and forebrain tyrosine hydroxylase by S-adenosylmethionine: a model that may explain the occurrence of depression in Parkinson's disease." Charlton CG.
"Striatal dopamine depletion, tremors, and hypokinesia following the intracranial injection of S-adenosylmethionine: a possible role of hypermethylation in parkinsonism." Charlton CG, Crowell B Jr.
These studies are essentially saying that SAMe can damage the reward/movement system of the brain/induce parkinson's/deplete dopamine, in rats.
I'm wondering what Dr. Mariano's opinions are on this, is this something to be concerned about when supplementing with SAM-E for depression?