Is Seasonal Affective Disorder a Myth?

By Hugh Middleton, University of Nottingham | February 9, 2016 6:01 pm

(Credit: Stephen Harlan/Flickr)

A flurry of newspaper headlines have called into question the existence of SAD, or Seasonal Affective Disorder. Scientists, they reported, appear to have debunked a widespread conviction, that feeling low in winter time is a genuine illness caused by disturbed levels of brain chemicals and that demands treatment.

A visit to any number of Seasonal Affective Disorder (SAD) websites leads to online questionnaires offering “diagnosis”, treatment recommendations, and advertisements for light boxes – gadgets that simulate daylight and compensate for poor exposure to the real thing. SAD is identified as a form of depression caused by disturbances of hormonal rhythms sensitive to daylight, primarily melatonin. Unusually, intense exposure to artificial light often is advocated as a treatment. There is even a device that can be worn on the head, allowing the patient to use a light box on the move.

Where’s the Evidence?

The publication prompting the news story is a large US survey associating the experience of depression with season, latitude and sunlight exposure. Although various models confirm associations between the experience of depression and variables such as age, gender, education, employment and marital status, it found there were no associations between depression and season, latitude, a combination of the two, or sunlight exposure – as derived from knowledge of the respondent’s location and US Naval Observatory records.

These are high-quality data that have been analyzed appropriately. They also confirm similar findings that are equally unable to associate reported mental distress and fluctuations in daylight length, even those of the extreme type found in polar regions

The SAD Truth

So how might we reconcile the fact that seemingly conclusive research is unable to demonstrate an association between symptoms of depression and sunlight exposure, with the sheer number of people who believe they suffer from SAD?


Winter can be dreary, but a recent study found no associations between depression and season, latitude, a combination of the two or sunlight exposure. (Credit: Martin Janca/Shutterstock)

According to one source, SAD prevalence ranges from 9.7% in New Hampshire to 1.4% in Florida. In the UK, the estimate is that it affects 2.4% of the adult population. These estimates represent a large number of people – and their conviction that they are suffering from a real illness is often a strong one.

Indeed, SAD can even carry the juridical significance of a formal disability. According to the Los Angeles Times: “The US 7th Circuit Court of Appeals in Chicago ruled in October [2009] that a teacher could pursue a lawsuit against her former employer alleging that the school district had failed to accommodate her SAD, causing her mental health to deteriorate.”

The teacher in question had been obliged to work in a basement room without windows – and yet research is telling us that there is no measurable association between exposure to daylight and psychological well-being. Once again, in the field of “mental illness”, science and society are not singing in tune. Indeed, perhaps this is where the real conversation lies.

It’s Good to Talk

This story highlights several features of contemporary psychiatry that point to a need for changes in how the conditions it responds to are framed, understood and described. Distressing difficulties concerning emotions are nothing new, but construing them as a family of illnesses to be treated by healthcare practitioners is. Reflections on the past half century’s exploration of this approach has to conclude that it is often deeply flawed.

SAD and its treatment with light boxes is not the only “mental illness” where hard evidence and conventional practice are no longer in tune. Critical review of data accumulated in the course of antidepressant drug trials is beginning to suggest that even these, very widely-prescribed medicines might be associated with more harm than good.

Suggesting this challenges numerous interests and positions, but the resulting debate is a healthy and invigorating one. There may well be no evidence for such a thing as SAD, but that doesn’t mean we shouldn’t talk about it – especially when the days are short and the skies gray.The Conversation

(This article was originally published on The Conversation. Read the original article.)

CATEGORIZED UNDER: Mind & Brain, Top Posts
  • Uncle Al

    Healthcare must relocate this VICTIM! to Laguna Beach, CA (and pay mortgage, too). A fat dosage of Bupropion will transform that fevered brain into a refrigerated mess of pottage. There are 66 acknowledged side effects to provide entertainment against boredom.

    I fear being intellectually incapacitated to anoesis by anatidaephobia. Duck! Where is my golden palanquin (with handicapped sticker and Commuter Lane pass) borne on the shoulders of honest citizens?

  • nfojunky

    And yet it moves.

  • Erik Bowen

    OMG!!!! Vitamin D is a myth???????? And SAD doesn’t just have to do with light. It has also to do with barometric pressure and temperature. If I suddenly fall half asleep when the pressure falls I guess that isn’t real evidence. All these people people say they feel depressed when during winter conditions. All these people say they feel better when during summer conditions. Data? What data? This doesn’t agree with the energy level of bears so we are going to dismiss it? People often feel ‘creeped’ out in their own homes when the temperature level drops suddenly. Anyone notice that most ‘ghosts’ are seen on dark and damp or stormy nights? I guess this doesn’t agree with hundred of years of data either?

    • Rixware

      This post doesn’t actually say ANY of the things you think it says.

      So, let me recap: A very well-designed study of existing data showed that: “there were no associations between depression and season, latitude, a combination of the two, or sunlight exposure”. In other words, the data merely shows that lack of sunlight is not causing the symptoms people are reporting.

      It says nothing more than that. But this discovery does raise a host of interesting questions (which make up the rest of the post).

  • Rixware

    Living in the upper midwest, I know people who use SAD as a significant frame for understanding their cycles of mental health. There would be no (kind) way to tell these people that the condition does not exist.

    For someone who believes they have this condition, it is very real — in other words, for them, the condition exists regardless of what the data says. In that way it’s at least a little like “full moon fever.” We all know that crime and weird behavior spikes whenever the moon is full, right? Only it doesn’t, as has been shown by study after study. Yet still we believe it because we are dead sure we have observed it.

    And this leads right into the possibility that the underlying mechanism of SAD is actually confirmation bias. Once someone thinks they have this condition, any supporting evidence is amplified, and any non-supporting evidence is discarded. This can be a devastating spiral, especially when the condition is related to mental health.

    So the reality is that it matters how we talk about SAD. And this data may show that perhaps it matters even more just HOW MUCH we talk about it — or not.

    • OWilson

      I would suspect there would be correlation between so-called SAD sufferers with their conformational bias, and Global Warmists and other assorted doomsday prophets.

      Pessimism and depression are not strangers to each other :)

  • Leslie Buck

    First of all, to actually be diagnosed with SAD by a licensed mental health professional the person must meet the criteria for recurrent major depressive episodes. This means that those who have been formally diagnosed (not taken an online survey) are truly suffering. The depression is designated as SAD type if the individual has experienced a seasonal pattern to episodeS over the course of years not just one occurance. While major depressive disorder is unfortunately fairly common, the seasonal pattern does not occur for all those individuals.
    Second, the methods in this study are suspect as they looked at large groups of people in a general population and do not appear to have been looking at those same specifically diagnosed. I wonder how many other health conditions would be suspect with similar methodology? Where is the skeptic’s critical analysis???
    All this shows is that some people self misdiagnose. Again, I wonder how often this happens with other health conditions?

  • OWilson

    How many Psychiatrists does it take to figure out that a Vitamin D deficiency during long sunless northern winter months is not conducive to good health, mental or physical :)

  • Wilko

    Looking at the rapport I notice a few things: Mind you, I have little experience in the field of psychiatry, but have some in the social sciences in general, so let me make something clear: When i ask a question, I’ not asking it rhetorically. I am genuinely interested in the answers.

    First of all, a major critique seems to be the incompatibility of the SPAQ with the DSM. It was my understanding from (limited) encounters with psychiatric professionals that the DSM is far from uncontested among experts. The authors seem to suggest that outcomes from the SPAQ are inflated compared to the outcomes from DSM-related research. What evidence is there that the DSM-criteria do not significantly under report psychological phenomena? Any proponent of the SPAQ could easily argue that the DSM-criteria are not accurate, undermining the entire point of the study.

    Secondly, I’m interested in the non-response rates, which I couldn’t find. They used a phone-interview methodology. i can imagine that people with depression would be less likely to respond or seek contact with the outside world. If people with depression are less likely to participate as the seasons turn, than that might affect the data.

    Despite these questions, I thank the auhors for their interesting research. They are right in saying that depression is a recurrent illness and that seasonality can be a coincidence. I look forward to reading more.

  • ECarpenter

    This is interesting, but read the summary of the paper – they were measuring the relation of clinical major depression to length of days. Most people I know, including myself, don’t fall into the definition of “clinical major depression” during the winter but not the other seasons. However, we ARE distinctly affected when the days get short, and have many symptoms of depression. We can function, we can go to work and keep ourselves clean and fed, but it’s not a good experience. And it responds to light therapy – especially now that LED lights in the wavelengths which stimulate melanopsin are available.

    So I’m sure that these researchers found what they said they found, but that doesn’t mean that SAD is not real – they were looking at a pattern of experience that doesn’t fit most people’s experience of SAD.


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