I was dxed with a form of PTSD back in '84, and it very much interfered with my life until just a few years ago, with tons and tons of therapy and meds. I'm told I'll have to stay on antidepressants for the rest of my life because I am 'hardwired' for depression by my hellish past.
Before I had a better handle on it, it made it difficult to deal with the various A's in my life because they're bad behavior would trigger my own 'fight or flight' response. That doesn't happen so much anymore because I came to learn my triggers and how to deal with them without losing it completely.
It's possible to get better, but it takes a ton of work and determination.