Seasons, especially summer and winter, can be challenging for people, according to Norman Rosenthal, MD, a psychiatrist and researcher who led the team that discovered seasonal affective disorder (SAD). Rosenthal is also an author Beating SAD (Seasonal Affective Disorder): A Guide to Seasonal Health and Happinesswhich comes out in August.

Some people feel depressed in the winter, often because of the lack of sunlight during the short day, but others feel depressed, irritable and agitated in the summer, Rosenthal says.

When Rosenthal began researching seasonal affective disorder in the 1980s, he initially focused on people who suffered during the winter. But after learning from many people who experienced the “exact opposite” of winter SAD, his team began investigating summer SAD as well.

According to him, in people with summer SAD, feelings of depression and anxiety begin to appear when it’s hot outside, in May or June, and last until mid-September.

While winter SAD is often partly attributed to a lack of sunlight, Rosenthal says that summer SAD can sometimes be triggered by lots of sunlight, which some people find arousing and can negatively affect our sleep (which we know is important for regulating mood). Hot weather is also a likely cause of summer SAR.

However, Rosenthal added that “no one knows for sure” exactly what causes summer blues, and there may be other psychological factors, such as feeling anxious that everyone else is having more fun than you are, or being unsure about shedding the cozy winter layers and expose more skin. .

“When people are having such a great time in the summer and you’re not, you feel like you’ve been kicked out of some carnival that everyone else is in,” says Rosenthal.