ADHD husband reluctantly agreeing to the seminar

My ADHD husband and I are literally on the verge of divorce. We have been married twelve years, together fourteen. The beginning was great of course but as soon as we got married, it went downhill and has progressively gotten worse with each passing day. We have hung in there as long as we can but are both so miserable that we cannot even find any joy together any longer. 

So, a few weeks ago we decided to stop hurting each other and move towards divorcing. When I went to the bookstore looking for resources to assist in coping with divorce, I came across Melissa Orlov's Couples Guide to Thriving with ADHD. I read it in a day and then purchased the ADHD effect on Marriage. Reading the books was like reading a biography of our life. So, I discussed this with him and he is VERY reluctantly agreeing to do the seminar as a last ditch effort. 

Do we have any chance of turning things around if he is not going into this with a hopeful heart?