Much research probing the link between bullying and mental health has focused on how being bullied contributes to the development of issues like anxiety and depression. But a new study suggests the relationship goes both ways, finding that boys and girls with mental health disorders are three times more likely to be the bully.
The study, presented at the American Academy of Pediatrics' national conference in New Orleans on Monday, found that kids with Oppositional Defiant Disorder (ODD) -- which is characterized by frequent tantrums and revenge seeking -- were six times more likely to be identified as bullies than children with no mental health disorders, while children with depression were three times more likely. Children with anxiety and attention deficit hyperactivity disorder (ADHD) were also around three times more likely to be bullies, according to parental reports.
"There is a larger story behind why children bully," said study author Dr. Frances Turcotte-Benedict, a Brown University masters of public health student and a fellow at Hasbro Children's Hospital in Providence. "And part of that story may include the diagnosis of a mental health disorder."
She and her colleagues used data provided by the parents of some 64,000 children ages 6 to 17 as part of the 2007 National Survey of Children's Health. Approximately 15 percent of the children were identified as bullies.
Dr. Steven Meyers, a professor of psychology at Roosevelt University and a Chicago-based clinical psychologist who did not work on the new study, said the findings were not particularly surprising, at least in terms of ODD. That disorder, which affects between 1 percent and 16 percent of school-age children, according to the American Academy of Child and Adolescent Psychiatry, is characterized by many of the traits that are associated with bullying, such as aggression.
Nor was Meyers surprised by the finding that children with ADHD were more likely to be bullies.
"Even though, by definition, these children aren't angry or aggressive toward their peers, they do display traits that would increase the likelihood of having impaired social interactions," he told HuffPost. "If you're not really thinking through the consequences of your actions on the playground, you might not have the self-monitoring or restraint to hold back from bullying."
But Meyers said he was surprised by the finding that children with anxiety and depression were more likely to be bullies. Teachers and mental health providers do not think of children with such a diagnosis as being prone to bullying, he said, explaining they are considered "internalizing" disorders. One explanation, he said, is that children with anxiety or depression may perceive situations as being more negative or threatening than they truly are.
Additionally, a common stressor could lead to both a diagnosis for depression and contribute to that child lashing out and acting like a bully.
"For example, a child could be experiencing high levels of stress because his parents are getting a divorce," Meyers said. "That distress could be evident through depressive symptoms, but also could lead toward being aggressive to others."
Notably, the study found no differences between boys and girls.
"Both boys and girls with a diagnosis of any mental health disorder are more likely to be bullies," said Turcotte-Benedict. "However, when you look at gender and mental health disorders alone, white, non-Hispanic boys were more likely than girls to be diagnosed." Government estimates suggest that 1 in 5 children and teens in the U.S. have a serious, diagnosable mental health disorder that interferes with their day-to-day functioning. But only 20 percent get help, according to the National Alliance on Mental Illness.
Turcotte-Benedict said the new study emphasizes the need for continued research into the complicated link between mental health disorders and bullying in order to improve prevention efforts.
"We need to assess bullying prevention programs for their effect on children with mental health disorders," she said, "and whether psychological support for these children has any impact on bullying behavior."