Suggestions for successful initiatives

Everyone who has browsed the forums a little will have already noticed that there are countless realistic reports of situations that led to the end of the relationship. I believe there is a lot in common in all of them. But would it be possible to open a topic just with suggestions from those who have had real success in their relationships? I'm looking for suggestions on how to make the partner realize the extent of the problem for the marriage (he knows he has ADHD, but is unaware of the impact on the marriage).