It’s common to chalk cold-weather doldrums up to just another case of the aptly named SAD, or seasonal affective disorder—a depressive condition experts believe may be caused by a lack of sunlight in the darker months, which can upset the body's sleep cycles and even affect the production of the mood-enhancing brain chemical serotonin.
But research from Oregon State University, published online in the Journal of Affective Disorders, shows that people might be overestimating the impact of SAD on wintertime mood.
To be clear, the study doesn't disprove or negate the existence of SAD. “It's clear from prior research that SAD exists," says lead researcher David Kerr. "But our research suggests that it doesn't affect people nearly as much as we may think."
Kerr and his researchers asked more than 750 participants in Iowa and western Oregon to complete surveys about any depressive symptoms they might be experiencing; the questionnaires were filled out multiple times over the course of several years. That data was then compared with weather reports detailing how sunny it was outside when the self-evaluations were performed.
"We did find a very small effect during the winter months, but it was much more modest than would be expected if seasonal depression were as common as many people think it is," says study co-author and Columbia University researcher Jeff Shaman.
“In the winter, we may not have as much fun, we may feel cooped up and be less active," says Kerr, "but that's not the same as long-lasting sadness, hopelessness, or problems with appetite and sleep—real signs of a clinical depression."
So when the cold months hit, ward off boredom and boost your mood by finding activities that help you stay upbeat and involved. If the snow's piled high, a good cross-country skiing session could do wonders—especially under a bright winter sun.