This debate started in a thread about shut outs, so I'll start there with my comments. People do what they must do to protect themselves. Some of the protective mechanisms are unhealthy but typical. The shut outs are a part of this. If someone shuts out for a year or more (my DH did this in his past, before I was around), that is not healthy. It can lead to divorce. It can lead to financial ruin. But it happens. And sometimes that is necessary. NECESSARY? Yes, as sometimes a person has to hit bottom before they can want to get better and to learn better, healthier coping mechanisms.

Now, how does a life partner cope with that? Not well, usually! It would take a Mother Theresa type to stick it out for over a year of being shut out and having divorce papers filed against him/her, when the PTSD spouse decides they need to be alone, and that they are bad for everyone around them. Yet, it may be necessary, ultimately, for the PTSD sufferer to go through divorce, break-up of a family, and financial ruin.

So is this "justifiable"? I don't think I understand that part of the question, honestly. I think it is not uncommon. I think it may even be necessary for some people to realize they need to make some changes in their lives.

Now, when one gets into other behaviors, the term "justifiable" makes more sense to me. It is not "justifiable" to be physically violent to another human being, and our laws pretty much universally condemn domestic violence. That is a "coping mechanism" that is so dysfunctional as to bring the person to hit bottom in a jail cell, which is definitely society's way of saying no, this is not justifiable. Shut outs are better.