I’ve been that guy. I can’t justify his actions or attitude, but maybe I can explain a few things. It took me over 6 decades to discover and get diagnosed w/ ADHD. For me, that meant 3 marriages, 3 bankruptcies, numerous jobs, and relationships. And, the feeling that I was just crazy for not being able to relate to others view of the world.
1. A diagnosis is not a cure,
2. Pills are not skills. If he were diagnosed with diabetes and just started taking insulin without finding ways to change his lifestyle and cope with his disease, he might stabilize but never get better.
3. With knowledge comes responsibility. Being told you have ADHD requires a personal knowledge of what that means to you and how it affects you. And then it is necessary to find new coping skills to function in a way that others don’t feel “run over” or ignored by you. Hyperfocus is only a part of ADHD, there are other symptoms, maybe less apparent, that help reinforce it.
4. Counselors/coaches/therapists can help a lot, but we have spent years developing coping skills that don’t change overnight. This is partly due to the fact that we don’t want to give up the “dopamine highs” that we have come to expect in certain situations.
I was diagnosed only a few months ago and haven’t come to terms with all of the aspects of how I am affected. Some things are trial and error and some things work quickly. Life is a continuing process.
If he is motivated to work on the problems and understands the consequences of not working on them, and you can help him, then things might go well. And, it can be an adventure for both of you.
Don’t let yourself become a martyr. You have a life too. With patience and courage, things become possible.
Best of luck to you.