The Work-Neglect Continuum - Balance with an ADD Partner

I am in a rather new but serious relationship with a man who has nearly debilitating ADHD. If he is unmedicated he will go off grid and be unreachable, and contacting me doesn't occur to him. This I understand is not a slight against me and have made peace with it.

The issue I have is his tendency to become so focused on work, which he is especially passionate about since we both work for philanthropic causes. Probably not the healthiest of work schedules but we still feel too passionate to do less. There are days where we both come home exhausted but others I only get a, "Hello...going to bed." It is like the entirety of his mind is focused on work and remembering that I'm a few feet away is less than an afterthought. What's funny is that I know the reason and am usually successful at not taking it personally.

What I need to know is how to I remind him that I do need some occasional attention in a proper way?

Usually having some built-in personal space because of this phenomena is comforting but now I worry for the relationship. My typical relationship playbook doesn't cover dealing with medically induced neglect.