Does anyone here take SAM-e

I had almost a week of my head being more focused and now its suddenly gone and stuffed up on me again. (I like to meditate but with my concentration as shot as this, its impossible for me to do so), so Ive started researching trying to find something which will help my ability to focus and concentrate more.

Anyway in my searches I came across something called SAM-e which some suggest using for CFS. Its a precurser for serotonin and dopamine (both which can be affected in CFS).  Ive heard that my head symptoms can be caused by lack of dopamine and many of the CFS symptoms Ive had in the past were like parkinsons disease (tremors etc) and in parkinsons there is a shortage of dopamine.

So Im wondering if anyone here has tried SAM-e and if it helped them and in what way?