Do you blame the climate or lack of sunlight for your depressive mood? A new study has casted doubts on the existence of seasonal affective disorder, a depressive disorder linked to the lack of sunlight during frigid winter months.
Seasonal affective disorder (SAD) is a type of depression linked to the changes in seasons. It usually occurs in winter months in response to changes in the natural day and night cycle. About 10 million Americans are reportedly experiencing SAD and it is more common in women than men.
"The findings cast doubt on major depression with seasonal variation as a legitimate psychiatric disorder," the researchers said.
A survey of adults from the United States shows no evidence that levels of depressive symptoms change from one season to another. In the study published in the journal Clinical Psychological Science, the researchers collected data from a telephone survey of 34,294 U.S. adults as they were asked about depressive symptoms.
"We analyzed the data from many angles and found that the prevalence of depression is very stable across different latitudes, seasons of the year, and sunlight exposures," said Steven LoBello, an Auburn University at Montgomery psychology professor.
By using topographical location for all participants, the researchers collected season-related factors. Findings show that there is no evidence of depressive symptoms linked with any season-related measures.
The participants who answered the survey during the frigid winter did not incur increased levels of depressive symptoms than those who responded at other times.
"Results do not support the validity of a seasonal modifier in major depression. The idea of seasonal depression may be strongly rooted in folk psychology, but it is not supported by objective data," the researchers concluded.
Depression is a sporadic disorder and during winter months, people feel depressive episodes. The researchers, however, argue that when people report feeling depressed in winter does not mean that they are depressed because of the season. They added that SAD may be present but not as much prevalent as it is thought to be.
"Mental health professionals who treat people with depression should be concerned about their own and their patients' accurate conceptions about the possible causes of depression," LoBello explained. He added that when treatments are done despite false causes may not contribute to rapid recoveries.
According to Dr. Matthew Lorber, acting director of child and adolescent psychiatry at Lenox Hill Hospital, the presence of SAD may not be a reasonable diagnosis but drug companies recommend it to be recognized as one. The presence of SAD among many people in the population allowed them to market their medicines.
"That was a motivating factor in creating this disorder," said Lorber, who wasn't involved in the new study.
Photo: Sander van der Wel | Flickr