I think for me personally,whenever I stress out about something the act of stressing itself creates those imbalances and further causes damage.I think it's cortisol or something like that is released during times of stress,that and adrenaline,epinephrine
and a host of other powerful hormones are released..next thing you know I am in this horrible state and for me personally..it's from bottling up alot of what I am thinking and feeling without any real release of it.
Working out releases aggression but also increases testosterone,though I am rarely depressed after a good workout.
I just think I need better coping skills lol.
When I am manic,it's usually because of a lack of proper diet.When I am depressed
it's usually concerning a key unresolved issue or problem and I dwell on it,those problems usually arise during the times of when I am really out of whack in general;
diet,lack of sleep,too much alky etc.
Most of the time though I am pretty much even keel.