You're welcome JBB
And your concern is well founded. You can only know the success of the treatment by going through several months of the Tryptophan, after which you will have your own evaluation of a successful outcome or not. Again, I wish you the very best. Your wife is very welcome to correspond with me through e-mail (pmdd@mail.com) if she ever has any questions or concerns.
Here are some additional links you and your wife may be interested in, contains some very helpful information:
http://groups.msn.com/PMSandPMDD/treatments.msnw?action=get_message&mview=0&ID_Message=479&LastModified=4675467563471649490#RepliesBookMark... this is from a woman to me in a previous support group I managed -- she had remarkable success with L-Tryptophan too and she provides a link to an excellent resource for treating PMDD naturally.
http://www.moodcure.com/mainpage.html
This doctor has written several books, the one I found to be very relevant to PMS/PMDD is called "The Moodcure." It deals with using L-Tryptophan, diet and exercise to correct mood problems, and gets my highest recommendations. She is easily contacted through her web site (and has responded personally to my e-mail queries).
http://www.mercola.com/2001/apr/18/prozac.htm
... Dr Mercola was one of the first doctors to prescribe Prozac for PMS/PMDD, he has some interesting comments about this method of treatment, well worth the time to read his info. He has also published several books, and is easily contacted through his web site (his manager responded to some of my queries, but it is possible to set up an appointment to see the doc personally).
All the best,
Anthea