sleep schedules

Here's another question for everyone. My ADHD husband usually never goes to bed before 3 a.m.   I've seen other posts about erratic sleep schedules for those folks who suffer from ADHD, but was just wondering about the rest of you folks here. Are your schedules the same? When we were first married, I used to stay up with my DH so that we could go to bed together and maybe have some romantic time together, because he would never "do it" during the day. (sorry, don't mean to be graphic) But, regardless of how much or how little work he has, he will NOT go to bed earlier. He will even just putts around until he can "pass out" at 3am. He usually IS doing some sort of work, but a lot of the time, he's downloading material off the web, and/or playing video games. Is this the norm? or is this unusual?