excuses

Recently i have been once again exposed to Midlife Crisis and depression in someone i love. Once again i am struck with how easy it is to use depression as an excuse for bad/rude/unkind behavior towards loved ones. I realize a mid life crisis is a call for help....its the way a person on many levels gets their own attention to DEAL with issues being buried. SOmetimes people answer the cry and deal with it, sometimes they ignore it until chaos and bad choices engulf them and those they love completely.
When does someone step away from depression and make choices....not live by default?