Sticks and stones may break your bones but words will break your brain

“Sticks and stones may break my bones but words will never hurt me.” Sounds familiar? You may have been taught this witty maxim to fend off bullies during the glorious years that are high school. Since then, bullying has become a big deal: its often-devastating consequences are more than ever in the public eye. We already know that childhood abuse in many different forms (sexual abuse, physical abuse, witnessing domestic violence) can have long-lasting impacts. For example, sufferers are found to be more susceptible to depression and suicide, and more likely to engage in fights, do drugs and use a weapon. But what about verbal abuse from peers?

To evaluate the effects of peer verbal abuse on the brain and behavior, a team of researchers studied over 800 young adults who had no history of any of the big confounding factors such as exposure to domestic violence, sexual abuse, or physical abuse. The participants were asked to fill out surveys about how much verbal abuse they experienced from peers at school as well as surveys with more general questions about mood, behavior and psychiatric symptoms.

The results show that the more peer verbal abuse one is exposed to during school, the more likely they are to experience anxiety, depression, anger and drug use. As it turns out, verbal abuse from peers is just as bad as verbal abuse from parents in generating these consequences. As well, researchers found that peer verbal abuse that occurs during middle school years (ages 11-14) has the most significant impact (compared with elementary school and high school). I find that surprising, as I remember high school being much worse than middle school, but apparently it has to do with the timeline of brain development, not my personal feelings about high school.

To dig a little deeper, the researchers selected 63 participants who had experienced varying degrees of peer verbal abuse and had them undergo a brain scan (MRI). They found that participants who had been exposed to a lot of peer verbal abuse displayed abnormalities in their corpus callosum, a big bunch of white matter fibers that connect the left and right sides of your brain. The researchers suggest that this abnormality may explain some of the behaviors and symptoms associated with the abuse (such as depression).

While this study convincingly highlights the impact of bullying on the brain and brain function, there are a few things to keep in mind. Repeat after me: correlation does not mean causation. That undergoing bullying is associated with abnormalities in the brain does not mean that bullying necessarily caused these abnormalities. More studies will be needed to uncover that link. As well, the study is retrospective, meaning the authors “go back in time” by asking the participants to remember events from years ago. This can sometimes lead to faulty recalls or false associations. Lastly, I find it a bit strange that the researchers have not looked at the hippocampus of the participants. You may remember that the hippocampus is a brain region important for memory, but it is also involved in emotions, and it has been shown to be susceptible to other forms of abuse. I’m hoping the bullying-hippocampus link will be looked at in a future study.

Overall, though, the study reminds us that bullying is an important and potent childhood stressor. Sticks and stones it is.

Reference: Hurtful words: association of exposure to peer verbal abuse with elevated psychiatric symptom scores and corpus callosum abnormalities. (2010) Teicher MH et al. Am J Psychiatry 167(12):1464-71.