My experiments with nootropics continue. A few days ago, I started taking sulbutiamine (350mg/day), a synthetic analog of thiamine which differs in that it crosses the blood-brain barrier more readily. The effects were immediate, positive, and extremely dramatic - on an entirely different order of magnitude than I expected, and probably the largest single improvement to my subjective well being I have ever experienced. A feeling of mental fatigue and not wanting to do stuff - a feeling that leads to spending lots of time on blogs, playing video games and otherwise killing time suboptimally (though not necessarily the only such feeling) - just up and vanished overnight. This was something that I had identified as a major problem, and believed to be purely psychological in nature, but was, in fact, entirely biochemical. On the first day I took sulbutiamine, I felt significantly better, worked three hours longer than normal, and went to the gym (which would previously have been entirely out of character for me).

That said, I do have a concrete reason to believe that this effect is atypical. Specifically, I believe I was deficient in thiamine; I believe this because I'm a type 1 diabetic, and according to the research reported in this article, that means my body uses up thiamine at a greatly increased rate; I was only getting the RDA of thiamine from a standard multivitamin; and the problems I had seem to match the symptoms of minor thiamine deficiency pretty well.

That said, searching the internet finds people without thiamine deficiencies who also benefited from sulbutiamine, albeit to a lesser degree. And trying sulbutiamine is safe (no credible reports of adverse effects ever) and cheap ($17 for an 85-day supply as bulk powder), so I recommend it.