Frustrated non-ADHD spouses will often say to me something such as "It's so obvious that my partner should do X.  I don't understand why he/she won't!"  While a solution to the problem at hand may seem obvious, it's often really not quite so straightforward and here's why:

It's no secret that people with ADHD and those without it have quite different brains.  They approach things differently and perceive the world differently in part because the wiring in their brains encourages them to do so.   For example, you likely have different abilities to attend to things (ADHD symptoms = distraction and hyperfocus).  In addition, ADHD brains tend to receive information in a non-hierarchical fashion, vs. the almost automatically hierarchical way the non-ADHD brain usually works.  These differences mean that you might view exactly the same event but interpret it in completely dissimilar ways.  (Note, here, that I say "different" not "better" or "worse."  Don't fall into the trap of assuming that hierarchical is better, for example.  It's better in some situations and worse in others.)

But here's something you may not have thought about - how the effect of accumulated experience with ADHD affects your perception of the world around you and what you perceive your options to be.  A person without ADHD typically "learns" that there is a pretty direct correlation between how much effort one expends and one's ability to succeed.  Just try harder and you'll eventually prevail.  This is not the experience that the ADHD partner has.  An adult who has had untreated or undertreated ADHD often learns that there is very little correlation between effort and success.  Many with ADHD learn, instead, that they can't predict when they will succeed - no matter the effort - and that they often fail (at least by the standards set up for them in the classroom, at home and with their spouse).  Furthermore, when they are in a difficult marriage, they also "learn" that when they fail they may well be upbraided for it by a frustrated spouse who has lost much of his or her empathy for the difficulties that ADHD poses. 

If you are a non-ADHD spouse, I want you to put yourself into this situation and think about how you might respond:  Your marriage is crumbling, your spouse is frequently angry or frustrated.  He or she is often sharp with you, and frequently critical.  You have learned over the years that you can't predict whether or not you will be successful when you attempt to do something difficult, so you are wary of trying new things for fear of failure.  Your partner has become more and more convinced that you are the heart of the marital problems you both face and that you must do three specific things to prove to her that you're interested in turning the marriage around.

Would you jump up and attempt the three items, knowing that you don't know if you'll succeed or fail, and if you fail you'll be faced with further disappointment or criticism and things will get worse?  Or would you hold back and see if it might all pass?

You can use your imagination to put the shoe on the other foot if you are an ADHD spouse, imagining what it would be like to be used to always succeeding, and living with a spouse who often refuses to try your ideas.

This is all complicated by the fact that the method in which a non-ADHD partner might solve a problem, is often quite different from how an ADHD partner might find success.  So the "obvious" solution offered by the non-ADHD partner is sometimes not quite on target, though that's not immediately clear.

So, next time the two of you are at this very common impasse, think about how past experience affects your opinions about what is "reasonable" and what is not.  I think it will help you find more empathy and patience.  Learning about ADHD as an adult means lots of work to change the path of your own "history" and future - from not knowing whether or not you'll be successful to putting good strategies in place so that you know that, more often than not, you WILL succeed.  This takes time, hard work, and the patience of both spouses.  It's hard to gain the confidence to try at the beginning of the process if you fear that you will only disappoint your spouse if you fail.  So two things need to happen - the ADHD spouse has to be willing to try again, regardless of his or her fear of failure AND the non-ADHD partner needs to encourage the experiments it takes to find success.  Unless both spouses are willing to support experimentation - and that means both successes AND failures - little progress will be made.