It turns out seasonal affective disorder (SAD), a form of depression usually associated with the darker winter months, can take hold in the summer, too.

While its symptoms can be different from its winter counterpart — cold-weather SAD typically makes people lethargic, while summer SAD makes them more agitated — it’s also a condition triggered by seasonal changes.

That makes it an issue of particular concern amid the surge of extreme heat in 2024 and the spikes of temperature yet to come. As hot as June has been in the US, temperatures are only expected to rise in the next few months. These spikes underscore the effects of climate change and how rising temperatures worldwide are leading to hotter, longer, summers. That reality is likely to exacerbate summer SAD, and could make it more common.

“The hot environment is only getting hotter,” Norman Rosenthal, the Georgetown University psychiatrist who first described SAD, told Vox. “So that is what’s going to make this more important than ever, as a factor to reckon with in terms of mental health.”

Fortunately, there are things you can do to mitigate the effects of summer SAD, which can include feeling down, less productive, and wanting to be left alone. It can also makes people feel overstimulated and, in some cases, increases the risk of suicide.

The key to fighting summer SAD is to understand its triggers, including the influx of heat and light that come during this part of the year. That means finding shade, cool areas, and more. Here’s what you need to know about summer SAD, and what to do to overcome it.

Similar to winter SAD, summer SAD is prompted by unique seasonal developments.

Just as lack of light can affect people’s mood in winter, an overabundance of it, along with heat and humidity, can also affect people in the summertime.

Researchers have found that heat can make people more fatigued, irritable, and aggressive, and that excess light can do the same. Both of these variables can also interfere with people’s circadian rhythms and their sleep schedules, which can have mental health effects, too.

“The heat depletes you, takes your energy away,” Rosenthal told Vox. “The light agitates you.”

Kelly Rohan, a University of Vermont psychology professor who studies SAD, says there isn’t a lot known about why these attributes specifically trigger seasonal depression and that more work needs to be done on this front more generally. Because summer SAD is less common than winter SAD, it hasn’t yet been scrutinized to the same degree. About 10 percent of people who experience SAD do so in the summer, experts estimate.

Rosenthal notes that people who experience summer SAD typically have a genetic predisposition toward depression that can be triggered by seasonal developments. Rohan adds that seasonal allergies could also play a role because they increase people’s discomfort in the summertime and cause inflammation, which is linked to depression as well.

Although people who experience SAD in winter and summer share feelings of being withdrawn and gloomy, the other symptoms they have can be markedly different.

“In the summer, people feel agitated,” says Rosenthal. “And even though they’re depressed, they’ve got this excess internal energy.”

The combination of energy and agitation is linked to a higher risk of suicide. People in summer may be more activated and inclined to take action, for instance, while people in the winter are less energized and inclined to pursue it.

If you suspect you might have summer SAD, the best thing to do is to speak with a doctor about the symptoms you’re experiencing. As one way to evaluate the pattern of symptoms, Rosenthal recommends that people think back through the last few years and try to recall if they had negative mood changes tied to the start of the season.

Again, it’s important to note that seeing a medical professional is vital to address mental health concerns — and that this guidance is not a substitute for that.

Some of the recommendations that experts have suggested, however, are possible ways to curb certain symptoms of SAD.

Cooling the body down using tools like air conditioning and 15-minute cold showers is one way to ameliorate the negative effects of heat.

In one 1987 study, Rohan notes, one patient took multiple cold showers a day while also staying in an air-conditioned home. That approach helped improve their mood considerably, but it was tough to maintain when they went outdoors and were exposed to heat shortly after the study.

If options like that are inaccessible, other ideas for cooling down include visiting public spaces like libraries and museums, and bodies of water like rivers and lakes.

Shady areas, under trees and umbrellas, can be helpful, too.

Cutting down on light exposure using devices like blackout curtains can also help.

Reducing light in a room can be calming, says Rosenthal, allowing people to wind down a bit if they’re feeling agitated. “If you’re understanding that the temperature is a problem, that the light is a problem, you can adjust your environments to minimize these irritations,” he says.

Researchers have found that the use of items like blackout curtains can help improve sleep quality, too, ensuring that people feel better rested and less anxious.

Feelings of anxiousness and agitation can be related to how disruptive extreme heat can be to a person’s typical routine including sleep, exercise, and other regular activities.

Setting up a consistent daily routine can help maintain a sense of stability and structure despite these disruptions.

Experts emphasize that treatments that are used for depression more broadly — including antidepressant medication and cognitive behavioral therapy — also apply to SAD and can be used to address it.

“All antidepressants currently in use for general depression can be used for summer depression as well,” Rosenthal writes in his 2023 book, Defeating SAD.

Rohan echoed this point. She cautioned, however, that some antidepressants could interfere with the body’s ability to regulate temperature, and that it’s important to be aware of that when pursuing this route.