The U.S. Food and Drug Administration (FDA) has given it's approval for a drug to treat a condition known as Seasonal Affective Disorder (SAD).
Seasonal major depressive episodes affect around 6 percent of American adults and the new drug Wellbutrin XL is the first and only medication approved to prevent the disorder occurring.
Seasonal affective disorder, also known as major depressive disorder with a seasonal pattern, is typically characterized by recurring fall or winter onset of depressive symptoms, with symptoms subsiding during the spring and summer months.
While the exact cause is unknown, SAD is believed to be related to seasonal variations of light, as well as changes in certain brain chemicals, which may induce feelings of depression.
According to Norman E. Rosenthal, M.D., clinical professor of Psychiatry at Georgetown Medical School and medical director of Capital Clinical Research Associates it is a serious and under-diagnosed form of depression that affects millions of people each year in the United States.
Dr. Rosenthal says it may now be possible to prevent the predictable onset of SAD with medication by beginning treatment in the autumn season, prior to experiencing depressive symptoms.
A combined analysis of three clinical trials showed that Wellbutrin XL reduces the chance of developing a seasonal major depressive episode by 44 percent.
Rosenthal, who is widely recognized as the first psychiatrist to investigate SAD, as well as the author of numerous articles and a popular book on the topic, say it is no surprise that the prevalence of SAD is highest in the northern parts of the United States where winter daylight hours are shorter and people tend to have less exposure to sunlight.
Symptoms of SAD may include depressed mood, overeating (and carbohydrate cravings, weight gain, lethargy and increased sleep.
Although antidepressant medications have been used to treat the disorder the new studies with Wellbutrin XL were among the first to explore the possibility of preventing the onset of autumn-winter depression by starting treatment with an antidepressant early in the season, prior to experiencing symptoms.
Two placebo-controlled clinical trials were conducted during the 2002-2003 autumn-winter seasons and a third trial during the 2003-2004 autumn-winter season.
A total of 1,042 outpatients were enrolled in the autumn, prior to experiencing symptoms and a questionnaire was completed at screening to evaluate the historical pattern and severity of seasonal depressive symptoms.
Subjects received matching placebo or Wellbutrin at 150 mg/day for the first week, with an increase up to 300 mg/day and treatment was discontinued in the early spring.
The results of the studies show that the drug is effective in preventing seasonal major depressive episodes in patients with a diagnosis of SAD.
For all three studies combined, the depression-free rate at the end-of-treatment was higher in the Wellbutrin XL group than the placebo group.
Wellbutrin XL does however carry a risk a risk of seizure with higher doses and taking more than 450 mg/day increases the chance of serious side effects.
People should not use it if they have had a seizure or eating disorder, or if they abruptly stop using alcohol or sedatives, and it should not be used with monoamine oxidase inhibitors or medicines that contain bupropion.
When used with a nicotine patch or alone, there is a risk of increased blood pressure, sometimes severe.
To reduce risk of serious side effects, people should tell their doctor if they have liver or kidney problems.
Other side effects may include flatulence, constipation, weight loss, dry mouth, nausea, difficulty sleeping, dizziness or sore throat.
Wellbutrin XL is approved only for adults 18 years and over.