Re: update

Actually, SAM-E IS an amino acid. It affects neurotransmitters in the brain (ie. seratonin), similar to 5-htp and l-tryptophan. Here is an excerpt from Ray Shahelian's website:

"V5-HTP may sometimes start working within hours. 5-HTP converts into serotonin, and important brain chemical involved in mood, appetite, and impulse control. 5-HTP suits those whose Depression is associated with anxiety, restlessness, or racing thoughts. A disadvantage of 5-HTP is that it reduces sexual drive.
SAM-e a powerful nutrient that starts working within hours. A recent study found SAM-e was helpful even in depressed patients who did not respond well to Prozac and other SSRIs. SAM-e is best suited for those whose Depression is associated with low energy, low motivation, and no anxiety. For those whose Depression is associated with anxiety, 5-HTP is a better option. There is a risk for overstimulation with SAM-e use, hence dosage should be kept low and it would be good to take a day or two off when one notices overstimulation. SAM-e is not advised for manic depression."

It seems Sam-e can be an issue if too much is taken, or if the patient has a problem with anxiety also. 5-htp has no side effects that I know of...besides the lowered sex drive (I didn't find that to be the case with me, but it was an issue with synthetic anti-depressants) and the tendency to get sleepy if the dose is too much.

Any option that affects seratonin will definitely change your life.