The days are getting longer. People have already pushed their clocks forward. In the Eastern and Midwestern United States, the snow has started melting into great big puddles and the birds are finally singing again. For people with Seasonal Affective Disorder (SAD), the spring is the light – quite literally – at the end of the tunnel.
For another group of people, however, the trouble is just beginning.
Reverse Seasonal Affective Disorder ,aka summer SAD, is a condition in which depressive episodes are associated with warmer weather. While people with traditional SAD might perk up with the blooming flowers in late March, people with summer SAD might want to curl up inside their homes and pretend that winter will never end.
In many ways, the symptoms of summer SAD are the complete opposite of its winter counterpart. People with winter SAD are often plagued by oversleeping – people with summer SAD tend to suffer from insomnia. People with winter SAD tend to overeat and gain weight, whereas people with summer SAD often develop a poor appetite and lose weight. Both forms of SAD involve low mood and a heightened risk of suicide.
Causes of the SADs
Researchers have theorized that people develop traditional SAD due to the reduced daylight in the winter and autumn. This reduction in daylight interrupts melatonin levels in the brain, a hormone responsible for sleep-wake cycles. These sleep-wake cycles, also known as circadian rhythms, are critical for mood maintenance. Most people with traditional SAD respond to light therapy, a treatment that involves sitting in front of a bright lamp for a certain amount of time every morning. The light from the lamp replaces the lack of light outside, resetting circadian rhythms and causing a reduction in depressive symptoms.
What about people with summer SAD? Unfortunately, performing light therapy in reverse does nothing to alleviate symptoms. Norman Rosenthal, M.D., a psychiatrist who worked on some of the first studies of summer SAD, explained to NBC news in 2011:
“A person with summer SAD can stay inside, crank up the AC, and darken the room but then go outside into the heat and it’s as if they’ve never been treated.”
Instead of disrupted circadian rhythms, people with summer SAD might be dealing with allergies. In 2007, a group of researchers published a study in The Journal of Affective Disorders that linked increased summer SAD symptoms with higher pollen counts. They also found that peaks in the amount of tree pollen coincide with springtime peaks in suicide. Although it might seem strange to link allergies with depression, both cytokines and inflammation have been found to increase during depressive episodes, and more and more scientists believe that depression might actually be caused by the immune system. People with summer SAD might be responding to a spring-summer allergen that causes brain inflammation and, ultimately, depression. In the winter, when the allergen is no longer present, the brain recovers back to its natural state.
Symptoms of summer SAD
Now that the warmer weather is here, people should keep an eye out for symptoms of summer SAD. Symptoms might include: