I've been thinking about power balances in relationship recently, and the role that validation plays in maintaining balance between partners.  I want to propose that you consider doing an experiment to better understand the ways that you and your spouse validate each other (or don't).  If you understand this better it will give you information about how to diminish conflict in your household.

Validation is a form of sharing power.  If you respect a person enough to be able to see their logic and "believe" their feelings, you are bestowing stature upon them in your relationship.  Conversely, if you write off their ideas, you diminish them.  Learning how to validate your partner's feelings - acknowledging their reality - can go a long way towards keeping your household more calm and keeping arguments in check.

When conflict arises in your relationship there are several ways you can respond.  You can de-escalate the conflict, match the conflict, or escalate the conflict.  A sure-fire way to escalate conflict is to invalidate the partner's idea (or  diminish the person - same effect).  So if Susan says "I really hate that you never help out around the house", a defensive response such as "what are you talking about?  I always help out", a sarcastic "yes, dear" or even an "I can't deal with this" and leaving the room will escalate the conflict.  Rather than acknowledging her feelings with a simple "I'm sorry you feel that way, let's talk about it", Susan's partner has tried to invalidate her point of view.  This leads, in a very direct path, to resentment and hard feelings.  Susan may or may not be right, but her perception is that her spouse isn't helping out.  The only way to deal with it effectively and move on is to figure out what's going on, and then create a plan to deal with her feelings and with the situation.  Otherwise, she remains in limbo - unresolved and frustrated.

Non-ADHD partners fail to validate their spouse's feelings all the time, too.  When Bill says "I can't do X" and Linda replies "Of course you can do X - it's so simple" she is ignoring what Bill is telling her.  It is hard for a non-ADHD spouse to understand the complete feelings of "overwhelm" that many with ADHD experience or the shame/fear that can lead to inaction.  A non-ADHD partner's lack of understanding (and frustration) can make it easy to assume that their spouse's experience and feelings are similar to their own ("I could do it, so that means you could do it"), rather than unique and worthy of validation.  A better approach for Linda would be a response such as "I understand that you can't do X right now the way you've been trying, but perhaps there is a different approach you could take?"

I'm guessing that the two of you invalidate each other much more than you realize.  So try this experiment:  For two or three days, look at every response and reaction you have to each other and note it and rate it.  "1" is a wonderful interaction that validated your or your partner.  "5" is an interaction that completely invalidated one of you.  Criticism, contempt, stonewalling, sarcasm and defensiveness should all be noted as "5"s because these all invalidate the partner.  Paying no attention (for whatever reason) should also be noted in the poorer end of the spectrum (you can figure out later if it was due to the ADHD symptom of distraction or an intentional put down).  Criticism masked as "help" is a common invalidation to note, as well.  Any time you have an interaction - good or bad - write it down.  Note your own behavior, too.  This goes both ways.

To do this well, you'll need to sit down about once an hour and think about the interactions in that hour for those times you are interacting.

At the end of the experiment, find some time to sit down together and talk about what you've discovered.  There may be patterns, such as a non-ADHD spouse being particularly critical around a subject such as not getting enough attention.  It's likely that many of your invalidating actions are centered around ADHD symptom responses.  There may be areas of strength that you need to note, as well.

My hope is that this exercise will do three things for you:

1. Make you more aware of the frequency of this destructive behavior so you can diminish its presence in your lives
2. Get you thinking about better, more validating, ways to respond in these same situations in the future.
3. Help you decide to reinforce existing validating interactions

You may find this exercise a bit depressing.  But the first step in changing behaviors is identifying them.

We all have a right to hold our opinions.  Dismissing those of your partner shifts the balance of power away from the ideal of "partner" towards an unbalanced relationship in which one or both of you will be less motivated to make changes.  It also adds fuel to the fire of your disagreements.  Validating that your partner has the right to hold his or her opinions - and listening to what they are so you can learn from them - puts you on the path to more empathy and a greater likelihood of working out your problems.  You don't have to agree with each other, but validating each other's ideas is a "must".