What is Seasonal Affective Disorder? Is it a myth or real?

Licensed pharmacist Corine Ferebee: As the seasons start to change, people begin to experience a shift in their circadian rhythm (an internal process that regulates the sleep-wake cycle and repeats on each rotation of the Earth every roughly 24 hours). Many begin to fall out of step with their daily routine due to shorter daylight hours and less sunlight in the winter. This change can alter the mood and lead to depression. SAD usually lasts around 4-5 months.

Holistic psychiatrist Kelly Brogan, M.D.: We ask ourselves to exhibit the same level of energy and productivity whether it’s summer or winter. This expectation of constant high-functioning is a masculine energy can lead to a burnout. That’s when there’s a high risk of being diagnosed with depression. Maintenance of cycles such as the circadian cycle is so important that their disruption can lead to neurodegenerative diseases and mood disorders like depression. Seasonal depression is not a myth but in fact a disorder ― it’s a label given to those that carry the symptoms.

What are the symptoms of the disorder and how can one recognize them?

Beth Murphy, head of information at Mind: Symptoms include: Lack of energy for everyday tasks, weakened immune system, irritability, lack of concentration, overeating and weight gain, alcohol or drug abuse, feelings of guilt and worry, sleep problems, reduced libido and social and relationship problems. The difference between SAD and the “seasonal blues,” which are commonly confused with one another, is that SAD prevents people from completing daily tasks for months at a time.

National Institutes of Mental Health: To be diagnosed with SAD, a person must meet the following criteria: 1. They must have symptoms of major depression or the more specific symptoms. 2. The depressive episodes must occur during specific seasons (i.e., only during the winter months or the summer months) for at least two consecutive years. However, not all people with SAD experience symptoms every year. 3. The episodes must be much more frequent than other depressive episodes that the person may have had at other times of the year during their lifetime.

How common is SAD? Do some parts of the population have it worse than others?

FamilyDoctor.org: Between 4% and 6% of people in the U.S. suffer from SAD. Another 10% to 20% may experience it in a milder form. SAD is twice as common in women as men. Some children and teenagers get SAD. But it usually doesn’t start in people younger than 20 and the risk for SAD decreases for adults as they age. SAD is more common in northern states as winters are typically longer and harsher. There is also less sunlight because they are farther away from the equator.

National Institutes of Mental Health: No one quite understands why women are so much more likely to be affected. Some researchers have suggested fluctuating estrogen levels, affecting serotonin. 

Cleveland Clinic: Approximately 500,000 people in the U.S. suffer from SAD, and around 10-20% of the U.S. population suffer from milder forms.

Beth Murphy: Actually, the condition is often undiagnosed, making it difficult to know how many people suffer from the disorder. People with symptoms of SAD often experience two or three years of the condition before they are diagnosed. Regardless of the number of people worldwide who suffer from SAD, experts say that doctors appear to have a lack of awareness of the condition.

What are some ways to combat this disorder? Does lighting help?

Ferebee: The No. 1 way to combat this disorder is phototherapy or bright light therapy in the mornings. This has been shown to be effective in decreasing symptoms in up to 85% of women with SAD. Special devices such as 10,000 lux light bulbs are designed to treat this disorder. Another way is to go outside for natural light. It's often cloudier in the northeast and the north central states, so it can be harder to find natural, bright light, but just getting outside and going for a walk can make people feel better. Other ways to combat SAD include: regular exercise, lessening sweets, changing your venue, and taking vitamin D supplements.