An updated version of this page, based on 500 respondents, is here.
Some Highlights
Many of us are still tired, and/or need a lot of sleep, even when sleeping on our bodies' preferred schedules. This contradicts the idea expressed in many articles, that our sleep would be perfectly normal if we slept on our own schedule. There's more going on than just the timing of sleep.
Doctors frequently say that depression is the cause of sleep problems. The survey data suggest it is often the other way around.
Light therapy isn't the ultimate solution for most people, despite what many doctors seem to think.
Phase-delay chronotherapy is not a long-term solution for DSPD, and appears to involve unacceptable risk of the DSPD becoming Non-24.
There are a lot more sighted Non-24 people (our respondents so far are all sighted) in this small sample than most doctors would expect. One reason may be that Non-24 interferes so catastrophically with people's lives that they are more motivated to take the time to participate in a survey like this. But we suspect that sighted Non-24 is more prevalent than is commonly believed.
The following preliminary results come from responses of the 208 people who have completed the survey as of May 28, 2017. It is preliminary because we have not eliminated inconsistent entries. Also, we have not yet looked at correlations, for example to determine if some experiences are more common among non-24 respondents than DSPD respondents, or whether patients whose eyes are especially light-sensitive respond differently to various treatments. We need a bigger sample to do correlations, so we hope to get a lot more circadian rhythm sleep disorder people to take the survey.
150 have DSPD, and 61% of these have been so diagnosed
69 have Non-24, and 36% of these have been so diagnosed Comment: There are a lot more sighted Non-24 people (our respondents so far are all sighted) in this small sample than most doctors would expect. One reason may be that Non-24 interferes so catastrophically with people's lives that they are more motivated to take the time to participate in a survey like this. But we suspect that sighted Non-24 is more prevalent than is commonly believed. Comment: There may be several reasons why fewer non-24 people have been formally diagnosed: Many doctors don't recognize it, and some still insist it only affects blind people (our respondents are all sighted). Some patients started as DSPD, evolved into Non-24, and don't see the point in going back to their doctors, especially given the difficulty of scheduling an appointment in advance if their sleep schedule is unpredictable. Some people self-identifying as Non-24 may not understand the disorder, and may be mis-identifying.
9 have ASPD, and 11% of these have been so diagnosed Comment: We suspect that because these people have no trouble getting to work/school on time, they are less likely to see a doctor about it.
26 have ISWD, and 23% of these have been so diagnosed
Note: Some people have responded with multiple diagnoses.
Diagnosis
Of those formally diagnosed, 24%* took 10 years or more to receive an accurate diagnosis, from when they first sought help for their circadian rhythm disorders.
About 1/2* were wrongly diagnosed initially, many with multiple incorrect diagnoses over the years. Chief among these incorrect diagnoses: depression; and "nothing is wrong".
Tiredness
When sleeping on their body's preferred schedule: 42% feel alert during the day, 58% still feel tired. 19% feel very tired or worse.
On average respondents sleeping on their preferred schedule would sleep 8.9 hours, and 32% sleep 10 hours or more (actually 9½ hours or more, since we asked people to round to whole hours). Comment: Many of us are still tired, and/or need a lot of sleep, even when sleeping on our bodies' preferred schedules. This contradicts the idea expressed in many articles, that our sleep would be perfectly normal if we slept on our own schedule. There's more going on than just the timing of sleep.
Of those who have to get up (work, school, family), 55%* get 6 hours or less sleep on workdays (actually 6½ hours or less, since we asked people to round to whole hours).
Of those who have to get up (work, school, family), 61% are late for work or school at least once a week.
Other Sleep Disorders
41%* of respondents with a circadian rhythm disorder also have been correctly diagnosed with another sleep disorder, most commonly bruxism, sleep apnea, or restless legs syndrome. Comment: Many patients have multiple symptoms, which can complicate diagnosis.
Other Disorders
47% also suffer from depression. For 2/3 of those, the depressions started after the circadian rhythm disorder. Comment: Doctors frequently say that depression is the cause of sleep problems. This suggests it is often the other way around.
26% also get migraines.
49% of respondents felt they were unusually sensitive to bright light. Comment: Is this related to response to various treatments?
Treatments
Of the 80 people who tried light therapy, 29% are still using it. Only 18% achieved their desired sleep times. Only 25% said it helped somewhat or more. Comment: This includes people using other treatments as well as light. Clearly this isn't the ultimate solution for most people, despite what many doctors seem to think.
Of the 75 people who tried light restriction, 62% are still using it.
Of the 140 people who tried melatonin, most used it within an hour of bedtime. Only 36% are still using it. Only 13% achieved their desired sleep times. Comment: Melatonin should be taken much earlier to be most effective in shifting circadian rhythm.
Of the 68 people who tried phase-delay chronotherapy, only 1 said it helped indefinitely. 93% said it helped for a month or less or not at all. 29% said their DSPD became Non-24 after using it. Comment: Phase-delay chronotherapy is not a long-term solution for DSPD, and appears to involve unacceptable risk of becoming Non-24.
* these numbers have been corrected from the original post
Images courtesy of Invitae. The images were captured a few days after the data, so may not agree exactly.
