Here's another perspective:
I, too, have been diagnosed with a whole host of mental illnesses (anxiety, depression, PTSD, and a handful of others.) Most of it stems from an abusive/ neglected childhood. From my perspective, taking care of whatever it is immediately is a nonstarter. It can't happen. I'm still in survival mode. I need time to get out of that mode before I can talk out whatever went wrong. I need time to cool down, relax, and come back to earth. There are still triggers (even someone else's physical motions) that can set me into panic mode. I'm much better than I used to be, but I still have a long way to go.
Geek has learned my triggers. Those close to me have figured out the things that cause me to shut down and how to avoid them. I don't mean "shut down" in autistic terms. I mean it in terms of emotional shut down, nothing in or out until I'm able to get it off my mind. Until I can parse what happened or get it off my mind, I get disturbingly emotionless. After a while, most folks will pick up the bare bones (oh, shit, if I bring that up, Naiad goes all weird.)
After a while, most marriages/ long term relationships pick up the threads of how the other works. If both have mental issues, it can and often does take longer, because you're learning each other's screwy responses, as well as what the healthy one is. Couple's therapy is a blessing here.