For some students, the colder, darker days of winter only last from December to March, but for others this time period can seem to last longer because they have Seasonal Affective Disorder (SAD).

"Seasonal Affective Disorder, also known as SAD, is a form of depression that occurs primarily in the winter months and recurs each year starting in the fall and winter and ending in the spring," Mary Anne Knapp, clinical social worker for the Center for Counseling and Psychological Services (CAPS), said.

SAD usually has to do with the amount of sunlight a person is getting, David Johnson, professor of sociology, said. He said the winter climate has effects on people.

People may think they have SAD, but actually do not, he said. The official diagnosis is minimal.

"Eleven million people in the United States have SAD," Stefanie Dunk, UHS physician assistant, said.

About 4 to 5 percent of students are affected by depressive symptoms that are related to decreased light intensity and duration that occurs in the winter months, Knapp said.

People living in northern states are more affected by SAD than those living in southern states, Dunk said. This is because southern states are warmer and have more sunlight than northern states.

SAD can affect anyone, Dunk said, but women are more likely than men are to have it.

Men don't go to the doctors for being sad, therefore, women are more likely to be diagnosed, Dunk said.

Symptoms start when the days get shorter, she said. Since SAD is considered a mood disorder, some of the symptoms are typical of depression. Symptoms of SAD include mood swings, apathy, sleepiness, increased appetite, sadness, irritability, fatigue and withdrawal.

Patients affected by SAD like to sleep and eat more.

"They tend to hibernate like bears," Dunk said.

Suicidal thinking can be an issue or concern with SAD. Suicidal thinking can seem like an escape from painful feelings or frustration about loss of functioning that is sometimes associated with depression, Knapp said.

When spring comes, symptoms resolve and the patient becomes his or her regular self again, Dunk said.

"As with other forms of depression, treatment for Seasonal Affective Disorder begins with a thorough assessment of patterns of symptoms and a client's history and experience," Knapp said. "Common treatments include psychotherapy, behavioral adaptations and self-help activities like increased natural light exposure and exercise, and medications such as antidepressants."

Light therapy, which is when the patient sits in front of a light box, can also treat SAD.

"Light therapy involves exposure to full spectrum light from an artificial source which replaces the light lost during the shorter daylight of winter months," Knapp said. "Light banks generally range from 2,500 to 10,000 lux ... Lux is a measurement of light intensity entering the eye."

Although light exposure can help treat a patient with SAD, not all light exposure is valuable.

Hannah Oberseitinger, salon attendant for Simply Tan, 1635 N. Atherton St., said that tanning would not be helpful in treating SAD.

"Because the rays in tanning beds are so strong, customers need to wear eye protection, which blocks most of the light," she said.

Though tanning cannot help treat SAD patients, it can help improve your mood.

Teah Botticher (sophomore-animal science) said tanning can positively affect your mood.

"You usually feel better after tanning because it relaxes you," she said.

Although light therapy works, a combination of both medication and light therapy seems to have better results.

"In addition to full blown SAD, many people will feel a little more sluggish or irritable, but are able to compensate so that it doesn't interfere with their mood or functioning," Knapp said. "Self-help strategies include exercise, increased exposure to light, and planning activities that are fun and energizing. If you like winter sports or walks, you are in luck."