New research explains why it’s so hard to recover from being down in the dumps.

By Samantha Zabell
Updated November 03, 2014
Dusica Paripovic/Getty Images

While it might seem like boredom can last for hours, new research from the University of Leuven in Belgium suggests that’s not the case—in fact, the findings, published in the journal Motivation and Emotion, show that sadness outlasts every other emotion in the book. So why’s it so hard to shake off?

To investigate, they surveyed 233 high school students using a questionnaire that covered 27 emotions. The researchers were careful to clarify the difference between an emotion and a mood—emotions required a very specific onset point, and are triggered by a significant event. Moods have a more vague start and finish. Researchers asked students to recall events that set off each emotion, and to estimate the duration of the emotional experience.

Sadness, they found, was the longest-lasting emotion—by a lot, lingering nearly 240 times longer than boredom, irritation, surprise, or shame. Other emotions with high duration include hope, enthusiasm, and joy. Researchers believe one of the main distinguishing factors of an emotion's persistence is the event that sets it off. Those tied to significant life events—like loss—generally have more impact, as opposed to an emotion like boredom, which probably isn’t spurred by a life-altering moment. The second distinguishing factor was how much each emotion required a person to think things over—that’s why, for example, anxiety had a much higher duration than fear.

“Rumination is the central determinant of why some emotions last longer than others," study co-author Philippe Verduyn said in a statement. “Emotions associated with high levels of rumination will last longest.”

If you can’t seem to get yourself out of a rut, try these simple tips to be happier, or this 15-minute fix for a bad mood. If all else fails, just know that sadness did have a stopping point—it might linger the longest, but it didn’t last forever.