If you’ve ever sat in a therapist’s chair wondering if those bullies from junior high are responsible for your adult depression, a study published earlier this week in the British Medical Journal lends weight to your theory.
Researchers in the U.K. found that children who reported being bullied at age 13 were nearly three times more likely to experience depression at age 18 that peers who weren’t bullied. The researchers analyzed data from the Avon Longitudinal Study of Parents and Children, which followed 6,472 individuals from birth or early childhood to adulthood. Each participant was asked about bullying at age 13, and then tested for depression at age 18.
As 13 year-olds, participants reported whether they’d experienced bullying behaviors such as being called nasty names, receiving threats, getting hit or beaten up, or having lies spread about them; and how many times they experienced each type of abuse. At 18, the subjects answered questions about symptoms of depression. If results did indicate depression, the subject was asked how long he or she had been feeling sad, miserable or depressed. Of the participants who reported frequent victimization at age 13, 14.8 percent were depressed at 18.
Of course, a correlation between being bullied and becoming depressed doesn’t prove causation. But the researchers refined their results thanks to two decades worth of data on the subjects and their families. They adjusted for behavioral problems, exposure to stressful events or abuse in early childhood, and family characteristics such as maternal education, parents’ occupations and social class. The report calculates that 29.2 percent of the total risk of depression at age 18 could be explained by peer bullying in adolescence.
In an editorial accompanying the report, Maria Ttofi, psychological criminologist, at the University of Cambridge writes that based on this report and previous research “peer victimization significantly predicts depression.”
Her takeaway: parents and teachers need to take action. Ttofi notes that when asked, most adolescents in the study said they never told an adult about being bullied. “Parents and teachers need to…proactively ask children about school experiences beyond academic matters,” she writes. “Young people themselves need to endorse anti-bullying attitudes…and learn the importance of not internalizing the victim identity.”
According to the National Institutes of Health, 6.7 percent of American adults experience major depression each year. The World Health Organization calls depression "a leading cause of disability worldwide."