> Key part of this being "persistent or recurrent". The key part is that it's related to the circadian rhythm and time keeping. That it's persistent and recurr

> Key part of this being "persistent or recurrent". The key part is that it's related to the circadian rhythm and time keeping. That it's persistent and recurrent doesn't in itself distinguish it from other sleep disorders that may cause delayed sleep schedule, such as sleep-onset insomnia, or "bad habits" as you call it. > Adding a distinction could help. Perhaps "voluntary night owl" vs "involuntary night owl". If you want to address people affected by e.g. DSPD, and not "night owls" in general, it is perhaps just better to simply address them as such.