S-adenosylmethionine and affective disorder.

Several open and double-blind studies suggest that SAMe may have an anti-depressant effect, and further studies are indicated. SAMe may exert a beneficial effect selectively on endogenous rather than neurotic depression. SAMe crosses the blood-brain barrier. SAMe is involved in several central enzyme pathways relating to transmethylation and folate and monoamine metabolism as well as in membrane function and neuro-transmission. The neuropharmacology of SAMe's effect on mood and the switch mechanism has yet to be fully explored. The actions of SAMe on the dopaminergic system are as yet unclear. SAMe is a physiologic substance that is non-toxic and relatively free of severe side effects (with the exception of mania, which may be a manifestation of the basic mood disorder.