misdiagnosis?

My husband of 23 years has self-diagnosed himself with adhd. I am in complete agreement. Issues in our marriage have led us to marriage therapists for the last 2 years. Our counselors have told me they believe my husband has NPD (narcisstic personality disorder) , that I am being emotionally abused and that we should separate for the emotional well-being of myself and our children. I am not completely sold on that diagnosis, although that could be because I am conditioned to make excuses for him. It seems like a lot of symptoms of ADHD (casting blame, not taking responsibility, abusing others' property, interrupting, not being self-aware) are also symptoms of NPD. Is one condition often mistaken for the other? I don't want to stay in an abusive relationship, but I don't want to leave prematurely, if adhd therapy could help the situation.