LEWISTOWN As the days get shorter and the nights get longer, it's normal to be distracted by feelings of drowsiness and irritability as the body works to adjust to seasonal changes. But it's when these feelings develop into seemingly permanent fatigue, lack of interest and social withdrawal that a person may be experiencing seasonal affective disorder.
"Though S.A.D. is not classified as a unique disorder, it is a type of depression," said Dr. Nalin Patel, a psychiatrist with Geisinger - Lewistown Hospital. "It affects a person at the same time every year, usually beginning in the fall until spring."
Seasonal affective disorder, or seasonal depression, is caused by the body's biological response to a lack of sunlight, Patel said. The limited exposure to daylight creates an abnormal circadian rhythm, the body's natural response to light and dark, which negatively influences sleep cycles and hormone release.
"A person isn't diagnosed with S.A.D. until there has been a two-year pattern of experiencing the disorder at the same time each year," Patel said. "However, there is usually a noticeable change in mood, need for sleep and food cravings."
Though children and adults of any age can experience seasonal depression, it's most likely to occur between the ages of 15 and 55, Patel said. It's also four times more likely to occur in women.
According to the National Alliance on Mental Illness, the most successful treatment for S.A.D. is light therapy, involving daily exposure to a light box, which artificially simulates high-intensity sunlight. A person should have at least 30 minutes of exposure to the light box each morning from the time the symptoms begin.
Patients tend to respond to light therapy within two to four days, Patel said, but if treatment is stopped, the positive effects will also stop within two to four days.
Patients experiencing S.A.D. can also be treated with medication that is slowly decreased as the days get longer, or cognitive behavior therapy, which teaches how to understand thoughts and feelings behind behaviors.
For more information on seasonal affective disorder, visit the National Alliance on Mental Illness at www.nami.org or the American Psychiatric Association at www.psychiatry.org/seasonal-affective-disorder. Any personal questions or concerns regarding S.A.D. should be directed to a primary care physician.