Proverbs 22:6 (King James Version)
6Train up a child in the way he should go: and when he is old, he will not depart from it.
When someone goes through a trauma, one of the things he may do is separate himself from everything he used to be. He abandons his family, walks away from his job, changes his appearance, even eats different foods. Everything that comforted him, supported him, loved him before the trauma only serves to remind him that he is changed. His innocence is lost, and so he puts away everything which reminds him of that life.
As a spouse, parent, or child of a person with PTSD, you have to make a choice - let him walk away (in the belief that one day, he'll come back) or fight him 'tooth and nail' to keep him in a role to which he no longer feels worthy of living.
If you keep him close after he has changed, understand why he has changed and do not force him or expect him to be who he used to be.
If you choose to go separate ways because he is too different from the man he used to be, never stop praying for him.
The always-answered prayer is "Let God's will be done in his life." Pray it. When the person you love most in the world becomes a stranger, pray this prayer.
I do, every night.
When the World Says, "If you'd raised him right, he wouldn't be this way!"
God says, "You raised him right. He'll remember and and return to it one day."
Not my will but yours, God. Not my wishes but your Wisdom, God. Let your will be done in his life. Amen.