Science

The Winter Blues or Seasonal Depression?

In the wintertime, many may experience feelings of melancholy which they dismiss as winter blues, but these feelings could indicate a major depressive illness: seasonal affective disorder.

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It is a cold winter day, and your alarm rings first thing in the morning. You groggily drag yourself out from the warm comfort of your bed, complete your morning routine, and bundle up, ready to face the season’s harsh winds. After school, you go home, unwillingly finish your homework, and fall asleep. You repeat this routine every day, but notice that as winter progresses, getting out of bed seems to become harder and harder. You lose motivation to do simple things like studying or even going out with friends. While many of us may dismiss this melancholy as the winter blues, there is a chance it could be something more. These symptoms could be signs of seasonal affective disorder (SAD).

Seasonal affective disorder is a major depressive disorder that maintains a four to five-month cycle. For most, SAD peaks during winter and vanishes in summer, but for some, it can be the opposite. The specific seasonal trend leads to distinct symptoms. In the winter pattern, SAD symptoms include social withdrawal, oversleeping, hypersomnia, overeating, and weight gain. On the other hand, summer pattern SAD may present symptoms of increased anxiety, agitation, insomnia, and extreme aggression. Though summer pattern SAD is just as debilitating as winter pattern SAD, it is less common in comparison to the five percent of the population that suffers from the latter.

SAD is most prevalent in the wintertime due to changes in our internal clocks, sunlight deficiency, and hormonal changes within the body. Our circadian rhythm is highly sensitive to light and darkness, prompting releases of specific hormones, such as melatonin or cortisol, to adjust metabolism or spur activity. However, in the winter, the lack of sunlight signals to our bodies that it is nighttime. This disrupts our natural circadian rhythms by releasing signals throughout the day that mistakenly tell us we should be asleep. This disruption can increase fatigue or cause depression, as an imbalance in the circadian system can lead to neurological dysfunction. Individuals with SAD also tend to have lower levels of serotonin, a neurotransmitter that regulates mood. MRI and CT scans show that individuals with SAD have more serotonin transport proteins, which remove the chemical from the brain. Sunlight keeps these proteins relatively low, but as the nights grow longer in the winter, transport protein levels dramatically increase. Furthermore, sunlight deficiency in the winter decreases the amount of vitamin D the body receives, making it difficult for it to support healthy serotonin levels.Thus, serotonin levels decrease in the winter months, impacting the brain’s ability to regulate feelings like anxiety and happiness. Changes in sunlight exposure also cause the bodies of people with SAD to stimulate more melatonin production. The increased amounts of melatonin, a sleep hormone, result in extreme fatigue throughout the day. All these changes can disturb the body’s natural cycle, making it harder to remain happy and motivated.

Though some individuals suffer from SAD symptoms, there is also a milder seasonal condition that most people have: the winter blues. The winter blues are caused by the season’s shortened daylight hours and cloudiness, which limit sunlight exposure. While the same physiological changes cause both conditions, there are differences between SAD and winter blues. For one, SAD has unique causes, including changes in serotonin transport proteins and melatonin production regulation. Another difference is that while individuals with the winter blues experience sadness and fatigue, these effects are temporary and moderate compared to those associated with SAD. While the winter blues are depressing for many, they are limited to the winter months, not debilitating to simple tasks, and not guaranteed to return annually. Winter blues can affect anyone and can be treated easily with vitamin D exposure, a healthy sleep schedule, and regular exercise. In contrast, a SAD diagnosis requires a professional opinion, and once diagnosed, requires medical treatment, such as medication or therapy.

SAD is commonly treated through antidepressants, primarily selective serotonin reuptake inhibitors (SSRIs). SSRIs treat depression, increasing serotonin levels in the brain by blocking its reabsorption in the neurons, thus improving the transmission of neuron messages. Bupropion is another second-line medication used to treat SAD in cases where SSRIs are not used. Bupropion targets specific conditions like anxiety disorder symptoms, and is not frequently associated with side effects impacting libido. Medication use is solely up to the decision of a patient and their doctor; an important factor to consider is whether the patient is already on other antidepressants. Alternatively, some consider light therapy or phototherapy to be an effective treatment for SAD patients. Light therapy encourages the brain to reduce the production of melatonin and serotonin by mimicking natural light. Psychologists also recommend cognitive behavioral therapy, a type of talk therapy, to treat SAD.

Depression is a powerful feeling, one with the capacity to compromise quality of life. It can be difficult to maintain positivity and hope, especially when students have to juggle school stress, familial issues, and extracurriculars. Researchers are still looking for more effective SAD treatments, but emphasize the importance of self-care in combating mental illness. If you are diagnosed with SAD, the school support system—guidance counselors, trusted adults, and friends—are there to help you prioritize your mental health this season.