Couples make progress when both partners are engaged in the process of making progress. If you have one partner who is unwilling to engage, chances for progress diminished greatly. The issue would be trying to get out why this person is still undiagnosed. You can walk on eggshells only so far and doing so isn't healthy at any time.
Many romantic relationships touched by ADHD are marked by misunderstandings and emotional outbursts. Effective communication skills, however, can be learned. Melissa Orlov teaches strategies that will resolve conflict with your partner.