my depression is deeply rooted in a profoundly personal family misfortune. however in my late twenties i figured it all out; i'd get manic and then pay for it with weeks of deep black depression. i eventually found that if i put on the brakes to my manic phase,, just shut it down with iron discipline to keep myself on an even keel then it was easy to do the same as i felt myself descending into that black pit of hell.  ever since instead of being in a jagged mental landscape of peaks and troughs, i find myself gently rolling on a smoothly undulating surface.  get rid of alcohol and caffeine too. get rid of sugar.
Canada