PHILADELPHIA (CBS) – Have you been battling the winter blues? According to a new study, winter probably has little to do with it.
Researchers say a large-scale survey of U.S. adults provided no evidence that levels of depressive symptoms vary from season to season.
The research was published in Clinical Psychological Science, a journal of the Association for Psychological Science.
“In conversations with colleagues, the belief in the association of seasonal changes with depression is more-or-less taken as a given and the same belief is widespread in our culture,” says Steven LoBello, a professor of psychology at Auburn University at Montgomery and senior author on the new study.
“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 exposures.”
Researchers examined data collected in 2006 as part of the Behavioral Risk Factor Surveillance System (BRFSS,) a phone-based health survey conducted annually.
From there, researchers examined data from more than 34,000 participants. Depressive symptoms were measured using the PHQ-8, which asked the participants how many days in the previous two weeks they had experienced symptoms of depression.
Researchers found the geographic location for each participant, and they also obtained season-related measures including the day of the year, the latitude, and the amount of sunlight exposure.
The study found no evidence that symptoms of depression were associated with any of the season-related measures.
“The findings cast doubt on major depression with seasonal variation as a legitimate psychiatric disorder,” researchers say.
“Being depressed during winter is not evidence that one is depressed because of winter.”