Just because you keep your brain healthy doesn't mean you won't be depressed.
This I do not agree with, clearly along with others also. Having a very physically healthy brain will significantly reduce depression, our perception is key here, often people will say you are being depressed over 'nothing', sometimes there are valid reasons, sometimes one finds it hard to ascend from these reasons and thus becomes lumbered in the realm of this certain event which consequently brings on the 'chronic' aspects of depression, this lack of ability to ascend from these reasons is often based on the perceptual world of them.

So I believe it is more about perception, if one has a better physical brain then ones perception of certain events may be different, one may perceive it in a more positive sense as 'moving on' or 'being stronger' Iā??m sure you've all heard these phrases; "what doesnā??t kill me makes me stronger". So I believe that depression can have external causes yet treatment lies within the health of the brain.

If your body is generally healthy, if you exercise regularly and eat healthy you will generally see a reduction in fatigue and depression, science is not the ruling elite in the quest of the battle of depression and psychological trauma, 10 - 30 years is not a lot of research and backing behind the drugs they pump in to you.

I hear that tomatoes have over 10,000 antioxidants yet scientists know of a mere 100 of them lol.

Hope this helps.