Many people suffer with Seasonal Affective Disorder (SADs) and it's largely believed to have to do with the changing of the Seasons. People have a lot of guesses as to why it happens, but the three prevailing hypotheses are about Cognitive Behavioral priming, biological mechanisms, or circadian rhythm disorders. People assume SADs is treated solely with a SADs light, and this is wrong. Read on to read rambling and incoherent on-topic thoughts about my general opinion on this topic.
I don't have my citations handy at this moment and probably won't remember to fish them up when I get up from a nap later today, but if you get caught up on some claim in particular please leave a comment and I will try to get back to you with the source of information / explain my clinical experience working with compound comorbidity in a rehab center.
Biology is often invoked as part of misunderstandings of human psychology and the related conditions, for many years we pushed Serotonin Theory as the cause of Depression, and that turned out to largely be bunk. For SADs though, atop the typical Serotonin Theory pushers who want you on first line Lexipro for their prescriber kick-backs is a continuing over-estimation of how critical Vitamin D deficiency is. We have a lot of... conflicting data about the actual role of Vitamin D and how it contributes to our health. More-over, I seem to recall recent developments suggesting that our changes to diets and the sedentary lifestyle likely impact Vit D production more than merely missing out on sunlight. Your Circadian Rhythm depends on a lot more than "light levels" too, that hypothesis is based on contemporary experiences of light... many of our ancestors lived in regions with those very long Summer Days, after all. Much of "Screen Theory" depends on this axis of light-based stimulation, and there's really not a definitive cause-effect relationship.
Screen Theory of course postulates that the bandwidth of the light hitting our retinas matters for priming sleep. This is only partly true, and an amusing behavioral finding is that those with pronounced Circadian Rhythm disorders or pre-disorder symptoms also tend to use their screens a lot before bed. My experience at an inpatient rehab as a clinician and now as a narcoleptic is that this is more about coping mechanisms and the utter destruction of work-life balance (starting of course, as early as kindergarten). We don't socialize like we used to, we don't gather like we used to, we don't exist in community like we used to. The pedestrian experiences of our immediate relatives of walking into town to visit the library, or riding your bike with friends to the local park are indicative of a pre-suburbanization reality where cars weren't as dominant of every aspect of U.S. / Canadian society as they are now. People were literally exerted more, moving about and experiencing the ballpark and their surroundings.
This isn't as much an anti-screens conversation as it is an anti-suburbanization conversation. Walking more than 15 minutes one-way to a destination without walkable infrastructure is far more draining on someone compared to walking somewhere you are permitted to walk. Pollution of the air for example has much more significant effects if you are (1) Exposed Daily to it, and (2) do not exercise even mildly on a consistent basis. So we look at climbing rates of Allergies, Asthema, and other impairments to cardiovascular and respiratory health and point our fingers at the 'classic indicators', missing a lot of how our species behaved before the era of the Automobile. We are not runners, we are hikers. You know a species that runs down prey when you see it: they are very fast. We're not fast, we're persistent. Endurance is one of our key traits and we had evolved to prioritize maintaining a particular level of activity that is strenuous but not stressful. We do awful under extended stress, stress is an absolute killer, we don't want to pop the Cortisol cork if we don't have to.
As we approach the Holidays, consider that we're not just dealing with the angle of the Sun, which can be a factor; but also the increasing social isolation and disconnect between family members and peers. Consider how the unhealthy society we built is impairing all of us, not just a select few, and consider voting for walkability and a denser, human-oriented infrastructure system for our urban centers. SADs is a complicated animal without a particularly definitive mechanism, reacting to Serotonin Reuptake Inhibitors, Dopamine Reuptake Inhibitors, and yes even Tricyclics and the more exotic forms of anti-depressants out there. It's not just about sunlight, and more-over, it doesn't seem to have ever been about light hitting your retinas... it's more about your perception, your health, and your circumstances. Would you believe that SADs is commonly associated with the isolation of the Holidays? How about the change of activities? How about anxiety about going a week without pay, being axed during Q4 from your job every year, the anxiety of time after election season, the anticipation of interacting with the out of touch boomer relatives?
The above is not definitive either. There are (in my opinion) way less cases of legitimate Vitimin D deficiency to the point of impairment out there than the industry would have you believe. We are often approaching cut-off from measures established during a completely different social context; imagine if I still rated the psychology of transgender folks in line with DSM-III? That still had "Transvestic Fetishism" as the titular sole diagnosis, and was based on the FBI's profiles of noteworthy psychotic people like Jeffrey Dahmer. We are often hoping that our measures and norms were objective, and remain objective, but often miss how things change. Is the drop in male average Serum Testosterone caused by hormones in the meat and milk, or could it be just one of several deficits caused by a total change in the context of available foods, activities, and environmental factors? All it took for me to stop sleeping was my prefrontal cortex losing a neurons responsible for a major response pathway that controls blood pressure, perception of time, the sleep/wake cycle, and the precursors to control agents that mitigate histamines. That's how Narcolepsy works in type 1.
As a final note in the topic of brain related disorders and the larger field of psychology, false attributions and mistakes in casuality are a dime a dozen because of how fucking interwoven our mental health is with everything else. Depressed? Well, do you have Thyroid Issues? Cancer? Low T? Low E? Are you Pregnant? How about sick? Do you have Gout? How are your liver enzymes? How about your Kidneys? Maybe you need Pro-biotics for your gut Bacteria? Do you have ADHD? Were your parents ever one-time users of Meth or did mom drink alcohol while pregnant? Do you smoke? How often do you exercise? How is work? Do you have a healthy relationship with your spouse? Are you overweight? What are you eating? Do you take Fiber? Are you Autistic? The list goes on and on and on and on and on, Depression is a common symptom of many disorders and diseases, including Chron's Disease, Pre-Diabetes and Rheumatoid Arthritis. Anxiety is often a comorbidity of Asthema and Cardiovascular syndromes, OCD shares more with the Trauma Response than anyone gives it credit for; this shit is complex.
One thing that gave me pause some years ago was the data correlating Coal Dust exposure with Autism. Another was correlating ADHD/Autism with hormone and endocrine disorders. Then we had epidemiological studies finding that many people in the Netherlands became Autistic rather abruptly when they were born in the years following a famine at the end of WW2. Imagine, if you will, that these things interconnect and overlap, causality is modeled often as linear, but may in fact be much more statistically atypical in nature than our understanding at a given time permits. Laura K Dale has a text about the intersection of Autism, Queerness, and Transgender identity, and the literature is in fact finding these are more closely interconnected than first advertised. Serotonin theory my fucking left ovotesticle.
Happy Thanksgiving if you like Thanksgiving. Fuck Thanksgiving if you are like me and only associate it and the immediate month afterward with drunken rednecks you are related to getting into fistfights every year.