Husband doesn't listen, has temper

I am new to this site, and to posting about my ADD husband.  A background on me: We have been married for 22 years.  In  many respects, we are a success story.  My husband has always worked hard to provide for the family, and I try to accept his disorganization, distraction and emotional disconnect (on occasion) patiently and with understanding.  We have 5 children, the oldest being 21, then 19, 16, 14, and 7.  Two of our children have shown strong tendencies towards ADHD. one of which has a diagnosis of ADD PI (primarily inattention).  I love my husband, he has many wonderful qualities.  He's charming, funny, hard working and is aware of his struggles with ADD, and tries to manage them all the time.

There are two things, however, that have been a strain on our relationship and his relationship with his children at various times in our family life.  He doesn't listen.  If I try to make a point, or argue an opinion, he will shut down the discussion, insist that he is right, or resort to belittling, hurtful comments.  Our children have all, at different times, expressed their frustration at not being able to talk to their father for fear that he will not respect their opinions or value what they have to say.  This is especially true if they try to express their negative emotions about something, or how they feel about what he is saying to them, or doing that bothers them.  Often, when discussions do go sideways, his temper flares, and he will over react to things so vehemently, I usually just shut the conversation down and walk away.  Currently our second oldest, 19 year old son is not speaking to his father, and has moved out.  Our 21 year old daughter has resolved to try and talk to her father about her feelings, and if he doesn't listen, she will walk away from the relationship for awhile (she is married and lives away from home as well).  Both of these things bring me great stress.  I should mention that I am currently in counselling myself for mild-moderate anxiety brought on by the stress level in my home and life right now - much of which has to do with my husband's relationship with my son. 

So my question is this: Is a flaring temper, the inability to be flexible and give and take in a conversation, or insisting that they are right a common trait in ADD/ADHD?  Or is my husband just an overreactive highly strung overbearing person? 

Any opinions or questions would be appreciated.