By Shelby Deering

Every winter of my life, it arrives as surely as the below-freezing temperatures or sales on swimsuits: Seasonal Affective Disorder, also known as SAD or seasonal depression. As soon as Daylight Saving Time hits, the symptoms come along with it: low mood, lethargy, a loss of interest in things that usually make me happy, and a persistent desire to eat every carb in sight.

Defined by the National Institute of Mental Health as "a type of depression that comes and goes with the seasons," SAD symptoms often include feelings of hopelessness, appetite changes, and sleep problems in the winter. According to Norman Rosenthal, M.D., the pioneer who first identified the condition over three decades ago, SAD impacts about 6% of Americans. Studies also indicate that the condition affects more women than men.

When spring arrives, I know that I will literally have a spring in my step once again. As the temperatures rise and the days get longer, I find that I exercise more, think positively, and feel like myself again. But there is a group of people out there who feel exactly the opposite when summer is around the corner. In fact, they feel the same way that I feel in November.

This condition is known as summer SAD, and it’s a form of seasonal depression that flares up during the summertime. While other people might be planning summer trips, hitting the pool, and going to picnics, those with summer SAD might not be in the mood for those activities.

Arpit Aggarwal, M.D., a psychiatrist with University of Missouri Health Care, explains that the most common symptoms of summer SAD include a sad or irritable mood, loss of appetite, weight loss, agitation, insomnia, and suicidal thoughts. People diagnosed with summer SAD have experienced these symptoms for at least two years. Dr. Aggarwal notes that out of everyone who experiences seasonal depression, about 90% have the classic winter SAD and the other 10% have summer SAD.

What causes summer depression?

While experts believe that a lack of light can cause winter depression, the reverse phenomenon could instigate the summer version of the disorder.

"The exact cause is unknown, but it is believed that changes in brain chemicals such as serotonin and melatonin are possibly due to too much sunlight," Dr. Aggarwal explains.

Sunlight availability can cause fluctuations in melatonin and serotonin levels, and our brain chemicals can deeply impact a variety of mental health disorders. For example, low levels of serotonin transmission in particular areas of the brain have been linked with depression.

Changes in circadian rhythms due to longer days and unpredictable schedules during summer breaks could also affect summer SAD, he adds. This can disrupt the body’s internal clock, which could lead to seasonal depression.

The phenomenon of FOMO, or "fear of missing out," may trickle into summer depression as well since social feeds appear packed with friends’ fun and exciting lives.

"It's the expectation that ‘everyone else is having fun except me,'" Dr. Aggarwal says.

How is summer depression treated?

While everyone else is gleefully lighting sparklers or hanging at the beach, you might feel as if your days are less-than-sunny. Summer SAD can absolutely impact day-to-day life, and according to Dr. Aggarwal, it should be treated with the same seriousness as any type of depression.

"As with any form of depression, SAD can cause problems with everyday activities like maintaining a job or a relationship," he says. "The lack of motivation and energy makes it harder to keep up with daily life."

If you suspect that you might be dealing with summer SAD, your very next stop should be to your doc. "One should never take the symptoms of depression lightly," Dr. Aggarwal says. "If someone feels sad for more than two weeks at a time and it starts interfering with your daily living activates, you should talk to your primary care doctor or a mental health provider to see if counseling or medications are needed."

Dr. Aggarwal also suggests a routine that includes adequate sleep and exercise. "Exercise promotes positive changes in the brain, including the production of endorphins or 'feel-good' chemicals," he says. "Adequate sleep provides the brain with enough rest to restore its circadian rhythm."

By seeking help for your summer SAD symptoms and practicing some self-care, you might notice an improvement before you know it. We may even find you on a volleyball court or going for a swim, soaking up the fun of summer.