"So, what can a person do to break this cycle?"

The million dollar question....

A pocket full of money goes a long way in relieving depression.

I know exercise helps, watching what you eat, changing your routine or trying something new occasionally is good, getting away from the boob tube and spending time with yourself is good, and get enough sleep .Having a driving passion or two in your life helps alot, one that does not need to be boosted by OTC drugs, caffeine, alcohol, tobacco, etc..

each mood has different rate of breathing,by regulating and controlling the breath you will go a long way to over ride reactive mood ,,,,,the rest is in your head