Fifteen-year-old Rhiann had taken to falling asleep often and neglecting her homework, her appearance and even her mother for the darkness of her room. Her style—from her clothes to her curtains—soon began to reflect this darkness.

“I realized I was out of control, not acting like myself at all,” she says, now a 16-year-old junior living in Virginia Beach, VA. Strangely enough, Rhiann’s symptoms disappeared in the spring.

Rhiann was misdiagnosed with stress and depression before her condition was correctly identified as Seasonal Affective Disorder (SAD), also known as “seasonal depression,” or a form of depression triggered by a change of season.

Winter Blues

As a high school freshman, Rhiann’s symptoms had developed gradually, first triggered by the onset of shorter days and more winter-like darkness early in the fall. “My first symptoms were really wanting to go outside, hating fluorescent lights and dreading the classes I had with no windows,” she explains.

Interestingly, there is also some evidence of “summer depression.” Symptoms of this rare form of seasonal depression can resemble those of a manic episode: agitation, weight loss and even hyperactivity. But, it is much more common to be affected in the winter.

Too little exposure to sunlight often results in Rhiann’s specific type of SAD, which can be associated with oversleeping and weight gain, among other symptoms.

“It appears that Seasonal Affective Disorder is another variant of depression…defined by when people are likely to get it,” explains Dr. John Manring of SUNY Upstate Medical University in Syracuse, NY. “It shares many of the same symptoms as any depressive episode.” The symptoms include those you might hear on a commercial for antidepressant medication: depressed mood or irritability, changes in eating or sleeping patterns, a loss of interest in once enjoyable activities.

These symptoms, especially in teens, are commonly mistaken for signs of stress, or mood swings. Unlike stress, however, seasonal depression is a "recurrent condition," which means it comes back at the start of every winter, not with every term paper. And unlike mood swings, seasonal depression can last for the whole season before normal sleep patterns and energy levels return.

“It gets really confusing when the symptoms suddenly go away in the spring,” Rhiann says. “It’s a terrible feeling to be unmotivated all the time just because of the season. It also affects your social life. I had no life outside my room on weekends.”

It’s believed that seasonal depression is more likely to influence people the farther they live from the equator. “One sees increased rates or incidence of SAD the further north one goes,” Dr. Manring explains. He says that SAD is more prevalent in places like Alaska, where about 12 percent of the population is affected versus places like Florida where about 3 percent of the population is affected.

Light Provides Relief

Luckily for Rhiann and others with the winter version of SAD, treatment is relatively easy to come by. “Light therapy,” which requires affected people to sit in front of a special type of light box for about an hour a day (typically in the morning), simulates sunlight to make up for the light missed during the short winter days. Dr. Manring says the treatment can “mitigate or eliminate the symptoms”—especially when coupled with other forms of treatment like medication, counseling and outdoor exercise. Although SAD is a recurrent condition, as routine and expected by its sufferers as the changing of the leaves, it is also often manageable.

Although SAD is less common in teens than young adults, it does happen. And unfortunately, people with SAD or other forms of depression may turn to risky behaviors like cutting or alcohol and drug use in an attempt to feel better.

There is help if the winter weather triggers extreme feelings of sadness or hopelessness. If you or someone you know shows signs of either version of SAD, tell an adult you trust, and get to a doctor or clinician right away. Whether you’re diagnosed with SAD or not, it’s good to talk to a professional about your symptoms and what you can do to feel better.