A new large-scale survey of U.S. adults did not find higher levels of depressive symptoms during winter months or at times of reduced sun exposure, questioning the existence of seasonal affective disorder (SAD).
The Auburn University at Montgomery findings, published in Clinical Psychological Science, a journal of the Association for Psychological Science, provide no evidence that depressive symptoms vary seasonally.
To find out if depression spiked in winter, researchers examined data from a 2006 survey of 34,294 participants ranging from age 18 to 99 who were queried about their health using a common diagnostic tool (the personal-health questionnaire [PHQ-8]). Participants were asked how many days in the previous two weeks they’d experienced symptoms of depression.
Researchers also used geographic-location data to obtain season-related measures, including the actual day of the year people felt depressed, their latitude, and the amount of sunlight they’d been exposed to.
The results showed that respondents surveyed during winter months or at times of reduced sun exposure did not have noticeably higher levels of depressive symptoms.
Further, researchers found no seasonal differences in symptoms when they looked at a subsample of 1,754 participants who scored within the range for clinical depression.
“The findings cast serious doubt on major depression with seasonal variation as a legitimate psychiatric disorder,” the researchers concluded in the study.
However, since conditions with so-called “low base rates” — the rate at which something normally occurs — are difficult to detect in large-scale studies, researchers note it’s possible that major depression with seasonal variation exists in a small subset of the population.
“Mental-health professionals who treat people with depression should be concerned about their own and their patients’ accurate conceptions about the possible causes of depression,” says senior author Steven LoBello, PhD, professor of psychology at Auburn University at Montgomery, Ala. “Pursuit of treatments based on false causes is unlikely to lead to rapid and durable recoveries.
6 Strategies for Fighting Depression
Up to a third of people in the United States experience a decrease in mood and energy during winter.
Whether you endure a mild case of the winter blahs or suffer from clinical depression, lack of light can make dark times even harder.
Here are some strategies that can help manage depression during any season.
Let there be light. For people suffering from depression, 30 minutes of sunlight a day is all it takes to provide an antidepressant effect. If you can’t catch the sun’s rays, a light box emitting full-spectrum light of 10,000 lux can decrease the duration of melatonin secretion in the brain while increasing positivity-boosting serotonin and other neurotransmitters.
Steer clear of sweets. Simple carbohydrates trigger an insulin surge, leading to increased serotonin production in the brain creating a rush of good — but short-lived — feelings. Light digestible vegetables, complex carbohydrates, like beans, legumes, and root vegetables, and lean proteins provide a nourishing boost.
Supplement your efforts. Eating foods high in omega-3 fatty acids, such as salmon and walnuts, can help the brain use serotonin more efficiently.
Keep moving. Getting to the gym or exercising outdoors can be a hard sell when temperatures plummet, but even a quick 10-minute indoor workout is a great defense against depression.
Mind your mind. Mindfulness practices like yoga, meditating, or keeping a gratitude journal can be powerful antidepression tools.
Make a connection. Spending time with others doing shared activities, such as walking, playing games, or going to a concert, are good ways to cope during rough times.