Spring. The weather will not be determined in any way, on whose side it is: either the sun shines brightly, or it rains. All these inter-seasonal fluctuations are depressing for many. And someone is driven into a real depression, and in this case, experts talk about seasonal affective disorder. However, new data raises doubts: does it really exist?
The concept of seasonal affective disorder was first described by the South African psychiatrist and scientist Norman Rosenthal in the 1980s. It is considered a subspecies of major depressive disorder. We are talking about depression, which worsens at the same time of the year (mainly in autumn or winter, the summer type of such a disorder is less common). Articles and books have been written about this disorder, ways have been developed to help such patients: in addition to traditional methods of treatment (antidepressants, psychotherapy, diet, physical activity), phototherapy is considered especially effective when the patient is exposed to bright light during the session.
It would seem that the picture is clear and definite. However, a new study calls into question the very existence of ATS.
At the beginning of their work, psychologist Stephen Lobello of Auburn University (Alabama) and his colleagues did not set themselves the task of disproving the existence of this disorder. They only wanted to pinpoint exactly when an SAD flare occurs, and to find out how its manifestations change from season to season. In addition, they were interested in whether the prevalence of SAD depends on a particular latitude. “We assumed that in northern latitudes, because of the short daylight hours in winter, this depression is more common,” says Lobello.
The researchers were unable to find a correlation between depression and daylight hours.
To this end, we analyzed data from one large-scale population survey conducted in 2006 by the US Centers for Disease Control and Prevention, in which respondents answered questions commonly used to diagnose depression. The researchers were primarily interested in the date of the survey and the location of the respondent. In each case, they determined the length of daylight hours at that location on the day of the survey.
As the data were processed, it became clear that no correlation could be found between depression, season, and daylight hours. The researchers at first did not believe themselves and assumed that they accidentally missed this relationship — they had to process too much data. Therefore, they further analyzed the responses of those respondents who were diagnosed with depression. However, no data has yet been found that would point to a seasonal disorder.
Maybe the answers were unreliable due to the fact that the survey was conducted by phone? This version also disappeared, since other patterns characteristic of those suffering from depression were fully manifested in the survey (for example, the fact that women and the unemployed are more likely to suffer from depression).
How to explain the results of this study? Maybe it’s about the questions. Researchers have previously wondered what time of the year depression is more often associated with and at what latitudes it is more common. But in previous surveys, the questions were related to ATS and may have unwittingly nudged respondents toward a given answer. And in the survey, which was conducted by the Centers for Disease Control and Prevention, only 8 standard questions were included to identify major depressive disorder, while specific questions related to SAD were not asked to respondents.
Lobello and his co-authors do not draw any categorical conclusions from the obtained results (it is clear that these data need further verification). However, it cannot be excluded that the scale of seasonal affective disorder is greatly exaggerated and that in fact only a few suffer from it, while other patients are misdiagnosed, suggests Lobello.
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