BY LINDSEY FEY and JOSEPH REY-BARREAU
UNIVERSITY OF KENTUCKY

As the days get shorter and the sunlight fades, many people notice a change in their energy and mood. Seasonal affective disorder (SAD), often called seasonal depression or the “winter blues,” is a type of depression that typically occurs during the fall and winter months when daylight hours are limited. Because reduced sunlight is a key factor, one of the most effective treatments for SAD is light itself.

Research consistently demonstrates that access to natural light is fundamental to human health and well-being. Decades of evidence in the field of health care design reveal that views of nature can reduce stress, lower blood pressure, improve sleep quality and shorten hospital stays.

Shedding light on SAD

Natural light is one of the most powerful environmental factors influencing human health. It helps regulate our circadian rhythms, the body’s internal clock that governs sleep, alertness and hormone production. When daylight becomes scarce during the winter months, disruptions in this rhythm can contribute to feelings of fatigue, sadness and loss of motivation and ultimately result in a SAD diagnosis.

Symptoms of SAD are typically consistent with those found in other types of depression such as persistent sadness, hopelessness, irritability and low mood. According to Mental Health America, however, there are some symptoms that more commonly occur with SAD than other types of depression including sugar cravings, extreme fatigue and sleepiness, increased appetite and weight gain. Mental Health America estimates 5% of the U.S. population experiences SAD each year.

How light therapy works

One of the most researched treatments for seasonal affective disorder is light therapy, which involves using a specially designed light box that simulates natural sunlight. The light emitted from these boxes helps stimulate the production of serotonin, a neurotransmitter that regulates mood, while also influencing melatonin, the hormone responsible for sleep.

Consistent use, typically 20 to 60 minutes each morning, can help reset your internal clock, increase energy and ease depressive symptoms within just a few weeks. For safety and effectiveness, light boxes should emit 10,000 lux (a metric for illuminance) of UV-free light, be used at the recommended distance as prescribed by a medical professional and should be positioned to ensure the light is hitting your eyes without a direct glare.

Exposure to daylight or light that mimics it has been shown to boost mood, improve focus and support better sleep quality. In health care environments, for example, studies have found that access to natural light and views of nature can reduce stress, lower blood pressure and even shorten recovery times.

Before beginning light therapy, however, it’s important to consult a health care provider, as SAD is a serious depressive disorder that sometimes requires a combination of therapies.

Designing for daylight

Beyond therapeutic devices, our everyday environments also play a major role in how light affects our well-being. A layered lighting approach balancing natural, ambient and task lighting can create spaces that support both physical comfort and emotional health. Ambient lighting establishes comfort, task lighting supports precision and safety, and natural light provides critical biological and psychological benefits. Together, these layers create spaces that can promote alertness and overall wellness.

To make the most of limited daylight during winter months:

• Maximize window light by keeping blinds open during the day and using reflective surfaces to help bounce light around.
• Choose light, soft paint colors such as warm whites, creams or pale grays to make spaces feel brighter. A flat white finish on ceilings can also prevent glare.
• Use adjustable LED bulbs with variable color temperatures (3,000 to 6,500 Kelvin). Cooler white light promotes alertness and energy, while warmer tones create a sense of relaxation.
• Opt for light-colored fabrics for curtains and furniture.

Lighting concepts can be applied in all spaces, but these tips are particularly helpful in living rooms and bedrooms.

Brighter days ahead

Whether through deliberate lighting design or small daily habits, simple changes can have a big impact on mood and overall well-being. Open the blinds, take a walk during daylight hours or carve out a bright corner near a window for your morning coffee. Every bit of light helps and remember, the darker months are temporary. Following the winter solstice in December, daylight has slowly begun to return. Each sunrise brings a little more light, and with it, a renewed sense of energy, balance and hope for the season ahead.

This week’s column is by the College of Design’s Lindsey Fay, associate dean for research and health care design scholar, and Joseph Rey-Barreau, associate professor and lighting designer with more than 45 years of teaching experience.