In autumn, as natural sunlight levels begin to decline and colder temperatures prompt us to spend more time indoors, it’s not unusual to experience a change in our mood and energy level. For most of us, this change is relatively mild and manageable. However, for individuals with seasonal depression, or “the winter blues,” that seasonal shift can be severe enough to significantly impact their ability to function and quality of life.
According to UTMC adult psychiatrist Dr. Victoria Kelly, seasonal depression—formerly known as seasonal affective disorder, or SAD—is not a holiday-related phenomenon. Rather, it’s a subtype of major depressive disorder that begins to manifest symptoms as daylight hours get shorter in the fall, worsens through winter, and continues until spring. The individual’s mood completely returns to normal from spring until the next fall. Seasonal depression is diagnosed only after this pattern has repeated for at least two years in a row.
Compared to other forms of depression, seasonal depression sufferers are more likely to struggle with symptoms of low energy, oversleeping, cravings for high-carbohydrate foods, and irritability. Other symptoms common to depression may include feelings of hopelessness or worthlessness, fatigue, loss of interest in pursuits they previously enjoyed, difficulty concentrating, and thoughts of death or suicide.
So how does sunlight exposure—or the reduction thereof—influence mood? According to Kelly, the decrease in sunlight passing through the eyes from fall through winter can have a significant impact on the neurotransmitters serotonin and melatonin, which are strongly associated with mood and the body’s natural circadian rhythm—the internal “clock” that regulates the sleep/wake cycle. Also, the vast majority of the Vitamin D the body needs is produced by sunlight exposure on the skin, whereas only a small percent comes from the foods we eat. Vitamin D is involved in numerous regulatory processes, including those affecting neurotransmitter levels in the brain, cell growth, neuromuscular and immune function, and reduction of inflammation.
Kelly notes that 4 to 6 percent of people meet the full criteria to be diagnosed with seasonal depression, but another 10 to 20 percent may have milder symptoms. People at increased risk of developing the condition are those who already have a mood disorder, such as depression or a bipolar spectrum disorder; females (four times greater risk than males); young adults; and those who live further from the equator.
While we commonly associate the onset of seasonal depression with the autumn time change, when symptoms are usually noticeable, Kelly notes that the condition actually tends to begin earlier than most sufferers realize—around the month of September. She states, “At that point, people with seasonal depression often just feel more tired and have less energy and motivation. They may also report feeling ‘blah’ or ‘empty.’ But if nothing is done to nip the problem in the bud, the symptoms can progress to more intense sadness, crying spells, and general unhappiness with life.”
Kelly explains that for people predisposed to seasonal depression, prevention is key. In fact, she urges her patients with the condition to start developing a game plan for fall as early as August. “This can be challenging for parents with school-aged kids because August is back-to-school time, but it’s so important that they take care of themselves and get ahead of those symptoms,” she says. “Preventive measures might include increasing exercise at onset and continuing through winter, increased outdoor light exposure or phototherapy, and Vitamin D supplementation with a doctor’s approval. Those with a predisposition to seasonal depression might also benefit from the prophylactic use of antidepressant medication.”
Phototherapy involves sitting in front of a full-spectrum, 10,000 lux, UV-filtered light box for approximately 30 minutes each morning. The person sits about a foot away from the box (which is tilted at a 45-degree angle) and can drink coffee, check emails, or read the newspaper during treatments. Kelly states that phototherapy yields improvement in three-quarters of patients who use it.
It’s noteworthy that in some cases, the severity of seasonal depression warrants seeking prompt professional intervention. “If at any point you’re having thoughts of death or suicide, or if the condition is impacting your ability to function—for example, if you can’t get out of bed to take the kids to school or you can’t get things done at work—you should definitely see a doctor,” Kelly advises.
If you suspect that you have seasonal depression, contact your physician or the Adult Psychiatry Outpatient Clinic at The University of Toledo Medical Center at 419-383-5695 for additional guidance.❦