Do you fight over whether or not you agreed to something in the past? Or perhaps you're a non-ADHD partner frustrated that your ADHD partner doesn't seem to remember your conversations? If so, I would like to suggest a simple solution that will help you avoid these fights.
Each time you have an important conversation that includes an agreement, write down that agreement in a journal. You don't have to write a ton of details, but agreeing what you will write down will help you distill the idea to its essence. In addition, the journal can be a place that an ADHD partner who suffers from short-term memory problems can refer to when suddenly faced with "what was it i was going to do again???"
Then, when you come upon a disagreement about what you agreed to, you can refer to the journal.
But that's NOT the end of the story. Nothing says that just because you agreed to something in the past means you MUST do that thing. You may have changed your mind - perhaps something has changed since you last talked.
The importance of the journal is not about keeping the agreement static and unbending. The importance of the journal is that you don't WASTE TIME arguing about whether you agreed to something or not. What you agreed to is in the journal. Now you can ask yourselves the more important question, which is "where are we today on this issue, and what do we do next?" Your conversation changes from the unproductive "he said/she said" fight into the more productive "making a plan." And, when making that plan, you have a reminder of how you felt about the ideas "back whenever" so you can use that as a starting place if you wish...or not.