Just in case you look into Julia Ross's book The Mood Cure, and just in case you decide to give 5-HTP a try - I am including an update, as it were, by Julia Ross herself. In her book, published 2002, she recommends 5 HTP quite a bit, tho she does say that for some people it is stimulating and leads to sleeplessness (tho she does not explain why), in which case she advises tryptophan. I have come up with 2 articles by her, which were written more recently, that explain why. She says the 5 HTP raises cortisol, whereas tryptophan does not, so that in a person with high cortisol in the middle of the night, 5 HTP is not the thing to take. Here is one, from 2011. www.juliarosscures Eliminating the Top Causes of Insomnia
Now I myself understand why sometimes 5 HTP backfired and kept me awake most of the night. Tryptophan is much better.
Just thought I should pass on this info in case you decide to give any of this a try.