Seasonality of human sleep: Polysomnographic data of a neuropsychiatric sleep clinic 2023 Seidler et al

While short-term effects of artificial light on human sleep are increasingly being studied, reports on long-term effects induced by season are scarce. Assessments of subjective sleep length over the year suggest a substantially longer sleep period during winter. Our retrospective study aimed to investigate seasonal variation in objective sleep measures in a cohort of patients living in an urban environment.

In 2019, three-night polysomnography was performed on 292 patients with neuropsychiatric sleep disturbances. Measures of the diagnostic second nights were averaged per month and analyzed over the year. Patients were advised to sleep “as usual” including timing, except alarm clocks were not allowed. Exclusion criteria: administration of psychotropic agents known to influence sleep (N = 96), REM-sleep latency > 120 min (N = 5), technical failure (N = 3). Included were 188 patients: [46.6 ± 15.9 years (mean ± SD); range 17–81 years; 52% female]; most common sleep-related diagnoses: insomnia (N = 108), depression (N = 59) and sleep-related breathing disorders (N = 52). Analyses showed: 1. total sleep time (TST) longer during winter than summer (up to 60 min; not significant); 2. REM-sleep latency shorter during autumn than spring (about 25 min, p = 0.010); 3. REM-sleep longer during winter than spring (about 30 min, p = 0.009, 5% of TST, p = 0.011); 4. slow-wave-sleep stable winter to summer (about 60–70 min) with 30–50 min shorter during autumn (only significant as % of TST, 10% decrease, p = 0.017).

Data suggest seasonal variation in sleep architecture even when living in an urban environment in patients with disturbed sleep. If replicated in a healthy population, this would provide first evidence for a need to adjust sleep habits to season.

Open access, https://www.frontiersin.org/articles/10.3389/fnins.2023.1105233/full

 

a big difficulty is that light, temperature and season (like hayfever) isn't the only thing that varies by these seasons. Many jobs have 'busy season'. Anyone near kids will have busy autumn term and it sort of being peak exhaustion without recovery as people push through the second half of that in mid-Oct to focus on the light at the end of the tunnel of easter. Those working in any educational or health-related sector, and probably many other sectors will have the same set-up.

Financial years can run to Apr for other firms making the 'other side' as it heads to summer a lot easier than the 4-5month run-up.

In the UK more bank holidays spring-end summer. Xmas is less of a break for most due to short break + having to do family duties and general hecticness of parties of all kinds getting jammed into the calendar.

Anyone doing study - even short courses through work or for fun - will tend to have these run in the same academic cycle types.

January is a common time for people to change jobs.

REM sleep tends to be associated with memory and locking to memory new things that you might have learned so hectic 'cognitive'/work environment

Deep sleep probably more possible when you've had a bit of activity and maybe less 'stressy-type' hecticness.

Neither are 'psychiatric' but situational facts that each dictates certain types of 'recovery or download processes' just like a computer would need certain types of updates or battery charges or defrag (but I find the psychiatric angle often doesn't seem keen on the idea that humans are supposed to have exactly the same needs and behaviours no matter what is being thrown at them ie the situational)