Teacher burnout may contribute to stressed-out students and vice versa, suggesting that stress may actually be contagious in communities, according to a new study out of the University of British Columbia. While it’s not uncommon for students to be under a lot of pressure — or for teachers to experience burnout — this is the first time research has found a potential link between the two. The researchers refer to the phenomenon as “stress contagion,” or the spreading of the physiological symptoms of stress and anxiety from person to person.

“This suggests that stress contagion might be taking place in the classroom among students and their teachers,” said Eva Oberle, lead author of the study and assistant professor at the Human Early Learning Partnership (HELP), in a press release. “It is unknown what came first — elevated cortisol or teacher burnout. We consider the connection between student and teacher stress a cyclical problem in the classroom.”

In the study, the researchers analyzed 400 elementary school kids and gathered saliva samples in order to test their cortisol. Teacher burnout ended up being associated with higher levels of cortisol, or the stress hormone, in students’ saliva. It’s difficult to say which one directly causes the other, but the researchers believe they play off one another. When teachers get stressed from inadequate support in the classroom or poor educational systems, their lessons are less organized and managed. Students, then, are affected by the stress and burnout, in turn increasing their own levels of anxiety. In other situations, students with anxiety or behavioral problems may be the source of stress for teachers. The study “is a reminder of the systemic issues facing teachers and educators as classroom sizes increase and supports for teachers are cut,” said Oberle.

As teachers “play a central role in establishing a positive and responsive classroom environment that is conducive to social, emotional, and academic growth,” the authors write, their mental health may have a large impact on students. Research has shown that depression and burnout often overlap, hinting that many burned-out teachers also suffer from other types of mental illness — and this may prevent students from learning as well as they would from a non-depressed teacher.

The research is supported by a 2014 study that found stress was contagious between mothers and infants. In the study, researchers measured parental and infant cardiac stress and the release of stress hormones when the mother received negative feedback after completing a task. It turned out that the mother’s stress — which could be manifested by changes in tone, voice, or smell — was passed on to the infant. Toxic stress at such an early age may change brain chemistry in the babies, as well as impair brain development. It may not be too hard to imagine that teachers can also pass on stress to their young students.

“It is clear from a number of recent research studies that teaching is one of the most stressful professions, and that teachers need adequate resources and support in their jobs in order to battle burnout and alleviate stress in the classroom,” said Kimberly Schonert-Reichl, an author of the study and director of HELP, in the press release. “If we do not support teachers, we risk the collateral damage of students."

Source: Oberle E, Schonert-Reichl K. Stress contagion in the classroom? The link between classroom teacher burnout and morning cortisol in elementary school students. Social Science & Medicine, 2016.