I do appreciate how the article cautions to people that going out and buying supplements of acetyl-l-carnitine most likely won't work.

"...Big questions remain, she added. “We’ve identified an important new biomarker of major depression disorder. We didn’t test whether supplementing with that substance could actually improve patients’ symptoms. What’s the appropriate dose, frequency, duration? We need to answer many questions before proceeding with recommendations, yet..."

an important step forward indeed.

@BeardedWonder Also somewhere I've an article on how people prone to depression don't process cortisol as well. If I find that one again will post it. The cortisol theory would explain how someone appearing to have it all just snaps & checks out, as both good and bad stress raise levels.

re: ACL, there might also be an absorption, retention issue .

@Qualia There are a myriad of possible things that can cause depression whether episodic or chronic.
I always hearken to this quote about anything neurological.

If the human brain were so simple
That we could understand it,
We would be so simple
That we couldn’t.

Emerson M. Pugh *