I recently learned about circadian rhythm sleep disorders, and my reaction was "holy fuck, three of these might affect me!" But after reading about them in more detail, two of those clearly don't apply and it seems like I probably have delayed sleep phase disorder. Across three different countries, in three very different situations, it seems that my sleep schedule when I'm not actively trying to maintain a "healthy" one settles around a bedtime of roughly 3 AM and a waking time of roughly 11 AM.
If I wake up much later than that, I feel depressed for the rest of the day. (Though if I went to bed too late the night before I can take a nap in the late afternoon without feeling depressed.) If I wake up much earlier, I feel tired for most of the day with a strong desire to take a nap, and after about a week of early rising a nap becomes a necessity, with me typically feeling tired in the same period.
I also wondered if I might have elements of irregular sleep-wake disorder and non-24-hour disorder. The first because most of my life I've gotten anywhere from an hour-and-a-half to most of my sleep (in middle school and high school) in "naps" in the early afternoon. However I still seem to have a preference for sleeping in the morning (both the wee hours and when it's light out), and when I'm not trying to force myself to get up much earlier than 11, or only doing it for a couple days at a time, I don't need to take naps. I also sleep less when I'm on what seems to be my natural schedule, which suggests I'm getting better sleep. Typically, if I'm on the 3-11 schedule I sleep for 7.5-8 hours, whereas when I'm not on that schedule I sleep for nine hours (even more when I'm sick or severely depressed).
The second because I've realized that my sleep has a tendency to slip later each night when I'm unemployed. However I've realized that the tendency to go to bed later seems to be a result of depression, I still wake up around 11 AM and don't take naps until later, if at all. When I have a job I never have this incremental shift later in bed times (even if I don't need to get up at eleven) and also seem to do well on this schedule.
I'm going to try to see a doctor about this. Based on what I've read about it, if I do have delayed sleep phase disorder, there's nothing I can do to treat it aside from what I've always done: force myself into a strict schedule and take naps when I can. I've noticed that even if I get myself on a semi-reasonable schedule (I typically try for getting up at nine, going to bed around one thirty, and taking a nap when I can), the slightest disruption will throw me back onto the 3-11 schedule, and this seems to be a common issue with people who have DSPD.
However knowing this would at least let me justify keeping this schedule and being on my natural sleep schedule might help with the depression. I might also be able to get accommodations for later hours in future jobs if I'm diagnosed with a legitimate sleep disorder, so it seems worth talking to a specialist about.
I know that a lot of people on TCS have issues with sleeping, so I'm curious: who all here knows your natural sleep schedule, and is it one of these circadian rhythm disorders?