BeeBee64
Letting him figure it out on his own is not a given. In my case, after decades of seeing therapists through a nearly 30 year marriage with a covert narcissist/closet addict (including SA) and BPD, I have finally found a therapist who focuses on Family of Origin work and am stunned at what I didn't see. Previous therapists blamed my ex's stressful job, but none of them saw his manipulations. Not our marriage counselors, not my counselors, not the individual counselors he saw. Of course he lied to us all. I was the one suffering from depression, they said. But now that I had someone take me through FOO work, it all fits. I see patterns not only in my choice of spouse, but also in my choice of unfulfilling job, and they track with my relationship with my father, who I previously thought was a hero, rather than someone who I now see is emotionally immature and selfish.
I share this because - given what you said about both you and your wife being unhealthy in his childhood - it sounds like a lot of the progress your son makes will depend on whether he finds a therapist who focuses on FOO.
So getting back to your question: You might share with your son that his early childhood wasn't the healthiest environment (that both of his parents had struggles and issues) and that he might want to find a therapist who does FOO work.
That points him in the right direction and opens the door for a conversation in which he can ask you to elaborate. And if he does, you need to be honest. That doesn't mean you point fingers at your ex-wife or his older sister. You could say: "I was depressed, overwhelmed with a lot of responsibilities and exhausted when you were young, and I was emotionally absent. Your mother and I argued a lot. Sometimes, I wonder if your mother has narcissistic traits, but even if she does, I needed to be present for you and I wasn't. I'm very sorry for that. I lost the opportunity to share some of your growing up and it undoubtably had an effect on your attachment style."
(Speaking of attachment style, experts believe that its formed with our first year, so I'm not sure that there is ever a time when we're too young to be messed up by our parents, as one of the other people commented.)
Also, you can further open the door by telling your son that if he does family of origin work you'd be willing to join a session.
This strategy let's you own your mistakes, and apologize for them, but put the ball in his court.
[This message edited by BlackRaven at 4:17 PM, Wednesday, January 19th]