Portland residents face darker afternoons as seasonal depression risks rise

The shift to standard time took effect across much of the United States on Sunday, November 1, bringing darker afternoons to Portland and the surrounding region. For individuals prone to seasonal affective disorder, this change in daylight marks a specific trigger that often initiates depressive episodes in the fall.

The condition, known as SAD, was first described in 1984 by Dr. Norman Rosenthal, a researcher at the National Institutes of Health. Rosenthal coined the term and noted that the acronym stuck because it is easy to remember. The National Institutes of Health reports that the disorder affects many more women than men.

Symptoms of SAD mirror those of clinical depression. Patients often report persistent feelings of hopelessness or pessimism. They also struggle with concentrating, remembering details, and making decisions. Medical experts recognize a milder form called subsyndromal SAD, as well as a less-studied summer variety of the condition.

Scientists are currently investigating why certain people are more susceptible to the disorder. No single cause has been identified, but research points to how the eyes process light. Specialized cells in the retina convert blue wavelengths from sunlight into neural signals that affect mood and alertness.

Kathryn Roecklein, a researcher at the University of Pittsburgh, tested individuals with and without SAD to measure their response to blue light. Her findings showed that people with SAD were less sensitive to blue light, particularly during winter months. This reduced sensitivity may explain why the lack of bright light contributes to wintertime depression.

Dr. Paul Desan of Yale University’s Winter Depression Research Clinic stated that many patients respond well to light therapy. This treatment involves exposure to a device emitting light approximately 20 times brighter than regular indoor lighting. Research supports using a light source with an intensity of about 10,000 lux for 30 minutes each morning.

Desan noted that while light therapy helps those with severe SAD, it can also alleviate milder winter fatigue. Devices range in price from $50 to more than $400. He warned that some products marketed for SAD are too dim to be effective. Yale offers a list of recommended products, and the nonprofit Center for Environmental Therapeutics provides a consumer guide. Patients with a doctor’s diagnosis should check with their insurance providers to determine if the cost is covered.

Antidepressant medications remain a first-line treatment alongside light therapy. Doctors also advise maintaining a regular sleep schedule and walking outside, even on cloudy days. Kelly Rohan, a researcher at the University of Vermont, highlighted cognitive behavioral therapy as an option with more durable effects. CBT helps patients identify and modify unhelpful thoughts. Rohan suggested taking small steps to enjoy activities, such as meeting a friend for coffee, to break out of a hibernation mode.