Researchers said they did not get any evidence that the symptoms of depression were linked with any of the season-related measures. Published in Clinical Psychological Science, the recent study generally identified that a "large-scale survey of U.S. adults provides no evidence that levels of depressive symptoms vary from season to season."
According to Science Daily, the researchers examine the data from different angles and found out that depression is very steady from any seasons of the year. The team led by Steven LoBello, the senior author of the study and a professor of psychology at Auburn University at Montgomery investigated the seasonal affective disorder (SAD), which is the "seasonal pattern" modifier for the analysis of depression. The report shows an increase of depressive symptoms in the fall and winter while fewer symptoms in spring and summer.
On the other hand, the new studies have tested the rationality of the SAD research stating that the criteria to identify the SAD do not support the criteria for major depression.
LoBello and his team conducted a study that involved 34,294 individuals with ages from 18 to 99. They measured the depressive symptoms using the PH-8, which queried the individuals on how many days in the preceding two weeks they had experienced the symptoms of depression. The team also acquired season-related measures that include the latitude, the actual day of the year and the amount of sunlight exposure.
The outcome of their study shows no evidence that the symptoms of depression vary from season to season. "Being depressed during winter is not an evidence that one is depressed because of winter," the researchers argued.
"Mental health professionals who treat people with depression should be concerned about their own and their patients' accurate conception about the possible causes of depression," LoBello concluded.
Psyche Central describes depression as a severe mental condition. In depression, the behavior, thinking, appetite and sleep of the patient do not function properly. The mental health biomedical organizations including the National Institute of Mental Health are conducting and researching the diagnosis, causes and more effective treatments of depression.
Watch this video that discusses the signs, symptoms and treatment of depression.
