Possibly related: I've been tracking Francisco Garcia-Lopes' work using low dose methylene blue to reverse mild cognitive impairment (MB helps to replace, then eventually re-regulate cytochrome c oxidase and so repair an electron transport issue).

I was curious as to whether similar work had been done with MB and Parkinson's. Turns out there has, and the researchers thought (in their abstract) that MB was upregulating BDNF. They had no evidence of increased BDNF, so it could be repairing a CCO ECT issue, but there's a possibility they're right and BDNF is involved.

Also: I see there are some studies using MB to alleviate depression — but I didn’t dig into any of those.

For anyone else thinking about chasing this goose, MB appears to work in quite different ways. In low dose (0.5–4mg/kg) it works as an electron donor (like CCO); in higher doses it steals electrons from the ECT.

Interesting world we live in...