There is an explanation for all of this, which came out in 2010 but was ignored because it is too technical and there was no proof, just a theory. But for me it explains everything:
https://psycnet.apa.org/buy/2010-06891-012The full content can be purchased, but it has been available on Scribd.com since 2023.
So, based on this theory, their chronic depression comes from an underactive endogenous opioid system, and what makes them interpret things in a way that makes them angry is an unconscious attempt to stimulate it.
So it's not that his PTSD makes him angry, but it may be used as an excuse. Or he might even try to retraumatize himself.
For instance, before knowing me, my wife traumatized herself by spending the night at the beach in a bikini. She says that it got too late, so the subway had closed, and she didn't have money to pay for a cab. Obviously she was putting herself at risk, and there were other solutions. During the night, she got her phone robbed and went through sexual assault. For the rest of the night, she tried to stay crouched to avoid being seen by other men. As a result, she developed a specific phobia around walking. But specific phobias are relatively easy to treat, and I have tried all possible ways of healing her from it, but nothing works because unconsciously she doesn't want to let go of the trauma. Instead, she keeps doing avoidance behavior, which worsens it. There were times in which we had to use a wheelchair. Now we use just mullets, but it's very limiting. She has already cried about not being able to heal from it and said that I didn't deserve to go through this. But it is her unconscious mind that doesn't allow her to heal. After trying regular psychotherapy and hypnotherapy, I found out that EMDR was ideal for her. She loves her EMDR therapist but kept avoiding the intense sessions, then stopped attending EMDR sessions. As I insisted, she rescheduled, but when her EMDR therapy was finally about to heal her with another intensive session, she missed it. And during the exact time of the therapy, she insisted that she wanted to go to the beach by herself. Guess what? It was unconscious, but she wanted to traumatize herself again. This is self-destructive and similar to a suicide attempt, but the goal is just to stimulate their EOS.
Two days from now, she will start a low-dosage off-label pharmacological treatment, and I am hoping it will fix this biochemical issue. If I'm right, then in a few weeks she should not feel the need to follow those patterns anymore. Then she would allow her brain to rewire in healthier ways. Otherwise, if the pharmacological treatment is not effective, then maybe it will take a few years of DBT before we can live together again.
Hopefully this helps you to make some sense of the nonsense.