Can life with an ADHD husband cause depression?

I started seeing a therapist a few months back. We've been mostly dealing with my self-confidence issues. I've already seen some important benefits. Somewhere around the time I started my therapy, my partner of 15 years (husband for 11) was diagnosed with ADHD. ANd suddenly all the suffering started making sense. (Btw, it is great that his diagnosis and me working on my issues have coincided, otherwise I don't think we would make it).

I don't think I'll tell you anything new here. For almost 15 years we've had a dysfunctional relationship. It is as much my responsibility as is his. I stayed even though there were times when I wanted to run. At the beginning it was not like that. I guess he was less stressed, life was less demanding...

I realize that he was doing his best but his symptoms were awful, ranging from verbal abuse, breaking stuff whenever he would get impatient and stressed to avoiding people and social situations, responsibilities,losing things, forgetting stuff etc.

Slowly during our relationship I became more and more isolated. I have no family to begin with and to make matters worse we moved to another state and I haven't made any new friends. I made some acquaintances but that's it. I work two jobs. He too has a stable job. He was always tidy and giving his best to be responsible keeping the complexity of a life to the bare minimum. I stay in touch with 2-3 close friends, but even they do not know what's been troubling us. My husband asked me not to tell anyone. 

Anyway, I haven't been the person I used to be since I met him (at 26). Quite the opposite.  I exist. I work. I have zero ambition. I don't want anything. I don't know what to do with my life. I used to be sociable, and now my favorite part of the day is when I am alone, reading or playing chess. How sad is that? I don't feel excitement when we discuss going on a holiday. I don't want to go anywhere. I feel as if I made a wrong turn and now I am on a narrow road and can't turn back. I feel as if I missed at least a few important opportunities. Knowing that he needs help and me giving my best to help him, I never wanted to have kids. I would never drag someone to this mess we were living and to be honest in some aspects my husband was the kid I was rearing.

With therapy and sessions with his shrink he is getting so much better! It is amazing. He wants to help me find a better job. Until now, with me being the only one taking care of everything, I simply couldn't imagine going for a more responsible, better paying job with fixed hours. I opted for two part-time jobs that allowed me to run around and when need be help him or clean up the mess. He remembered how ambitious I was, full of energy, leading people... I asked when? And he said at work when we met... Basically before and at the very beginning of our relationship. We both laughed.

But it made me wonder how much his ADHD, if at all, has contributed for the current state I am in. I recognize that my decision to stay was my responsibility. But is it possible to develop some sort of a depression with and ADHD partner?