In an experiment involving mice, the researchers determined that being bullied may alter circadian rhythm function in a way that's similar to the changes brought on by depression and other mental illness. The researchers carried out the study by exposing mice to physical and emotional stimulus to mimic the effects of bullying. They paired small mice with larger, more aggressive mice—the larger mice showed territorial behavior and pinned the smaller animals down after a chase.
In order to observe the effect, researchers placed micro-transmitters (which are similar to activity trackers that measure heart rate and sleep) on the smaller mice. According to their observations, the smaller mice experienced progressive sleep pattern changes—the most significant change involved the mice going in and out of deep sleep frequently. These type of sleep disruptions are often seen in humans who deal with depression. The smaller mice also saw flattened body temperature fluctuations, another side effect of depression.
But is this really surprising? Bullying is obviously stressful and mood-altering, and the fact that it could affect a person's health—particularly his or her sleep habits, which are obviously tied to mental state—is not out of left field. But research like this may help scientists better understand how bullying affects the body, and come up with treatments that can counteract those effects—in fact, the mice even showed improvement in symptoms when treated with drugs.
"While our study found that some stress-related effects on circadian rhythms are short-lived, others are long-lasting," said William Carlezon, PhD, the study's senior author, in a release for this news. "Identifying these changes and understanding their meaning is an important step in developing methods to counter the long-lasting effects of traumatic experiences on mental health."