What to do if I suspect ADHD in my husband?

I have been with my husband for 17 years and am finally convinced that he suffers from ADHD. Over the years, we have logged many hours in marriage counseling sessions. We have always fought a lot over many things including finances and spending money on unnecessary items. He is a very successful entrepreneur, but he has had several job changes to get to this point. He has explained that he is motivated by money so in order to get motivated he needs to buy things for countless hobbies that come and go....

He is a good father, but doesn't do any of the day to day responsibilities with them like transportation, appts,  homework, dinner. It is pretty much understood that his job takes precedence. If he happens to be home from work to eat dinner with us, I have to ask him for his help to get them ready for bed. Mostly at home, he retreats every chance he gets and spends endless hours in front of his computer behind a locked door. He likes to play video games and as of late I am wondering if he also watches porn. He drinks alcohol nightly. He stays up very late and sleeps in while I am left to get our young children ready for the day. About 3 years ago, he was evaluated once by a psychiatrist per the request of our marriage counselor  and he was diagnosed with a "slight mood disorder" and was told to watch his drinking, exercise and to keep an eye on things. He never followed back up on it - I think his fear is that they will say he needs meds.

I have secretly purchased Melissa's latest book about ADHD effect in Marriage, to gain insight into if this could be our issue. The personal stories in the book have resonated with me. I can see similar patterns in him with distraction, hyper focus, retreat and frustration.  I know I do not have the medical background to diagnose my husband, but I am convinced that he suffers from ADHD. I am pretty much at that hopelessness stage, but I am trying so hard to not be. I have turned to religion because I can't stand feeling hopeless and am hoping that he will suddenly turn a corner. I guess deep down I do love him. He is a good father and talented in so many ways.

How do I approach this subject with my husband? How can I let him know that maybe we should get him evaluated for ADHD? He is going to think I have lost my mind. Please help!