Last year, I was severely sleep deprived, but needed to focus. On a whim, I took 25 grams of micronized creatine and it removed the issue with the dampened cognitive abilities. It just worked. It's nothing I would recommend as a long-term solution to sleep problems, but as a possible solution in a pinch, it could work.

Just a word of caution, 25g has a very strong chance of causing intense bloating. I'm part of multiple athletic teams, and the general consensus is that more than 10g is generally "uncomfortable" for its bloat pressure effects.