Summer SAD - No, Really!

[gayle_yamazaki]

We've all heard about SAD (Seasonal Affective Disorder) in the winter, but who's heard of Summer SAD? It turns out that there really is such a thing.

While sufferers of SAD in the winter experience feeling sluggish, tendency to sleep and eat more, and feel other symptoms associated with depression, the people who struggle with summer SAD have a different experience. The summertime SAD symptoms can include insomnia, loss of appetite, weight loss and feelings of agitation or anxiety. What seems to make matters worse is that they often experience a sense of isolation, partly due to everyone else loving summer.

Recent research at Vanderbilt University suggests that winter and summer SAD may have something to do with when we're born. The mid-brain region, dorsal raphe nucleus, has been identified as a potential area that could be the source of SAD. This is an area that contains neurons that control serotonin levels in the brain. The research examined groups of mice that were born and raised in different "seasons." They artificially created seasons by regulating the amount of light the mice were exposed to across the day. Summer = 16 hours of light and 8 hours of dark. Winter = 8 hours of light and 16 hours of dark.

Summer mice were found to be more persistent in difficult tasks, more willing to engage in bold behaviors, and exhibited fewer anxiety behaviors. The summer-raised behaviors persisted even after the "seasonal" exposure to light wast changed.

This study examined mice, how about humans? Well, since researchers can't ethically or practically impose "seasons" on humans, the next best research is to examine longitudinal data. Columbia University researchers did just that. They compared 1,688 diseases with the birth dates of 1.7 million patients who had been treated at New York/Presbyterian Hospital/CUMC between the years of 1985 and 2013. The incidence of depression was one of the diseases studied and the analysis suggests that people born in the winter are more pron to depression.

If you're not as thrilled with summer being here as everyone else, you're not alone. http://www.smithsonianmag.com/science-nature/people-get-seasonal-depression-summer-too-180955673/?ut...

Here is the link to the article in the Smithsonian.