Is Seasonal Affective Disorder Real?

By Sander van der Wel from Netherlands (Depressed) [CC BY-SA 2.0 (], via Wikimedia

Seasonal affective disorder refers to a seasonal fluctuation in a person’s depression symptoms. Although the disorder is currently recognized by medical professionals, there is a new large scale study that asks whether or not it is real.

The Study

Seasonal affective disorder or SAD, was officially added to the Diagnostic and Statistical Manual of Mental Disorders back in 1987. It is relatively new in terms of psychiatric conditions and many question its validity in terms of diagnosis.

The effects of how the seasons impact someone’s mood has been around for generations. The idea that light and dark phases can impact one’s psychological outlook was mentioned millennia ago by Aretaeus of Cappadocia, he stated, “Lethargics are to be laid in the light, and exposed to rays of the sun, for the disease is gloom.”

Modern studies performed in the 1970s and 80s brought SAD to attention and secured its place in modern psychiatric medicine. However, is that going to change?

What is SAD?

Today, seasonal affective disorder is not considered a stand-alone condition, rather it is a specifier to a broader subset of major depression and bipolar disorders.

In short, a patient with SAD will have recurrent depressive episodes during the winter time. Conversely, people with SAD showed remarkable improvement in mood during warmer months out of the year.

These instances are how seasonal affective disorder has been described until recently. Over the past few years, a number of scientific researchers have questioned whether SAD is even a valid diagnosis.

Questions about SADs Validity

Some of the research done at an earlier time that brought SAD to attention, has been at least somewhat discredited. A lot of the information regarding seasonal variations in depression symptoms was gathered through asking study participants to recall past depression episodes that spanned a year or more.
Newer research, published in Clinical Psychological Science, takes another look at the disorder through a fresh perspective.

A large-scale study was conducted in the United States involving a research team using information from a phone-based health survey conducted in 2006. The survey was a part of the Behavioral Risk Factor Surveillance System. In all, data from 34,294 people was utilized, the age of the participants ranged from 18-99.

The symptoms of depression were evaluated using a valid measurement known as the PHQ-8. The number of days on which depression has been experienced was tracked for 2 weeks prior to the interview. Of the questionnaires responses, approximately 1,754 people were classified as depressed.

The data included geographic location, which led the team to be able to precisely define the person’s latitude and the quantity of sunlight at their given location at any time during the year.
When the data was analyzed, no seasonal variations were discovered.

Conclusion to the Study:

Senior study author Professor Steven LoBello stated, “We analyzed the data from many angles and found that the prevalence of depression is very stable across different latitudes, seasons of the year and sunlight exposure. The findings cast doubt on major depression with seasonal variation as a legitimate psychiatric disorder.”


The information provided on the is designed to support, not replace, the relationship that exists between a patient/site visitor and his/her health professional. This information is solely for informational and educational purposes. The publication of this information does not constitute the practice of medicine, and this information does not replace the advice of your physician or other health care provider. Neither the owners or employees of nor the author(s) of site content take responsibility for any possible consequences from any treatment, procedure, exercise, dietary modification, action or application of medication which results from reading this site. Always speak with your primary health care provider before engaging in any form of self treatment. Please see our Legal Statement for further information.

PsyWeb Poll

Are you currently taking or have you ever been prescribed anti-depressants?
Total votes: 3979