Children who are exposed to bullying — regardless of whether they’re the victim or the bully — have a higher risk of developing several psychiatric disorders as adults, according to a recent study published in JAMA Psychiatry.

Previous studies have suggested that childhood bullying could contribute to mental health issues later in life. But the current study revealed that, in addition to threatening a child’s physical and emotional safety in school, bullying was associated with a 20 percent higher chance of a severe psychiatric diagnosis by their late 20s. "Bullying often falls into the category that 'kids will be kids' and 'it's part of growing up,'" said Dr. Andre Sourander, of the University of Turku in Finland, according to HealthDay. "That's not true."

Nearly one in four students in the U.S. report being bullied in school, a space that’s supposed to foster a healthy, safe, and supportive environment for children, according to the National Bullying Prevention Center (NBPC). What’s more, a study conducted by the Centers For Disease Control and Prevention in 2013 found that 20 percent of high school students reported being bullied at school in the past year, while 15 percent reported being bullied online.

For the study, Sourander and his colleagues collected and analyzed data from more than 5,000 8-year-old Finnish children, who were followed until they were 29 years old. Of the kids, about 90 percent did experience any form of bullying, while 3 percent were bullies, nearly 5 percent were exposed to bullying, and 2 percent identified as both bullies and victims of bullying.

Of those who did not experience bullying, 11.5 percent received a psychiatric diagnosis by 29 years old. By comparison, nearly 20 percent of bullies, 23 percent of victims, and more than 31 percent of those who experienced both had psychiatric disorders that required treatment by follow-up. Those who were bullies or were exposed to bullying at age 8 had a markedly high risk for several mental disorders.

The study also found exposure to bullying was specifically associated with depression. This isn’t surprising, considering it’s also been linked to anxiety, psychological distress, and other mental health issues that require treatment in adulthood. "We need to understand the importance of early peer and school experiences for children," Sourander told Reuters. "We should integrate a mental health perspective to anti-bullying campaigns, because early intervention can prevent long-term consequences."

Bullying involves a range of behaviors, including hitting, making rude gestures, name calling, and spreading gossip or lies about someone, according to the NBPC. However, the spread of technology and the popularity of social media has also fueled cyberbullying, enabling bullies to harass others on social networking sites or via text messages.

Source: Sourander A, Gyllenberg D, Llola A, et al. Association of Bullying Behavior at 8 Years of Age and Use of Specialized Services for Psychiatric Disorders by 29 Years of Age. Jama Psychiatry. 2015.