Methylfolate for the MTHFR, which is just taking a vitamin. There are various things as you mention that can be used for dopamine/et al, but I wouldn't go down that path unless you have precise knowledge of what your doing. We know that these snps encode for these enzymes, but don't have any precision as to what defects have what effects exactly. It depends on the number of defects (having a half defect often means that the other half encodes correctly - we think), and it appears to compound as there are usually several snps that are involved in any particular process (Methlyation is especially complex). So, are the dopamine levels too low? How do you know, are you testing for dopamine? How so? What defines low, for you? And so forth. Additionally dopamine isn't the only neurotransmitter that is involved here.
So there isn't enough knowledge to do a lot based on genetic tests IMO. Despite that I've got my full genome, and am watching the research. One example, my biggest genetic risk factor is for APOE-4 which correlates to a 40%+ of developing alzheimer's. Except, Stanford researchers just combed through the data and found that it's true for women, not men. Big difference.
So in short I self monitor and have a particular, tailored health regime, but am very cautious about chemical treatments/drugs at this point. A homeopathic approach is the best we can do presently, and frankly that's a good starting place anyhow.
So then what are your polymorphisms for the MAO-A (rs909525, rs2064070, rs6323, rs3027399, rs2235186, rs1137070, rs2072743, rs3027407, rs6609257, and rs1799836) and COMT (rs165599, rs165722, rs165774, rs2020917, rs2239393, rs4633, rs4646312, rs4646316, rs4680, rs5993882, rs6267, rs6269, rs737865, rs737866, and rs769224) genes?
In my case, I don't have any issues directly related to dopamine. I'd trend toward low motivation levels and depression, because high MAO-A activity results in catecholamines aggressively being cleared out.
Based on my genetic data, it seems there isn't much going on (negatively) in this regard other than the MAO-A issue, so the solution (for me) seems fairly straightforward. Furthermore, due to my Val/Met COMT V158M polymorphism, it's likely I'll have high(er) dopamine levels once MAO-A is inhibited. That is, without doing anything (except maybe supplying raw material like L-Phenylalanine), I'll naturally have higher dopamine levels, meaning not only will my motivation issues be gone, I'll swing to being someone that's
very motivated but without anxiety, restlessness, or paranoia.