Hot ADHD tip from someone with ADHD:
When you're reminded of someone, tell them.
Since ADHD causes us to have a skewed sense of time and that "out of sight out of mind" problem, it's easy to accidentally let your relationships deteriorate. So when you see a meme that reminds you of someone you haven't talked to in a while? Send it to them. If you are reminded of an experience you once shared, let them know you were reminiscing. See an old photo you haven't thought about in a while? Send that to them, too. Let them know they cross your mind. You're not bothering them. They care.
This includes people you talk to all the time and significant others. While the iron is hot, let people know you remember them. Because we are prone to getting lost for a while and that's not our fault.