As an alternative heads up, our entire experience of reality is subject to the whims of poorly understood chemical and physical homeostatic states. I just recently decided to pursue some genetic testing due to the night and day difference in my mood and motivation supplementing methylfolate (B9) and methylcobalamin (B12) had on me.
It turned a mild bout of depression and long standing un-medicated adhd on it's head to the point that I feel like telling anyone who is looking for a "strategy" to first make sure their biology is in order. It helps loads. In any case, if someone knows how sound the science around MTHFR is I'd love to be wrong on the internet and hear about it (about 1 in 5 is the rate I was quoted for abnormalities with that methylation cycle).