Bullying and the Brain

Pick up your favorite young adult novel or start watching the latest teen drama on your favorite streaming app, and chances are, one of the major plot points will involve bullying. While such stories may lead you to believe that bullying, defined by the American Psychological Association as “a form of aggressive behavior in which someone intentionally and repeatedly causes another person injury or discomfort,” is just a childhood rite of passage, many studies show it can have long-term effects on an individual’s health and well-being. Research studies looking at links between bullying and the brain have demonstrated it also can have significant cognitive and emotional consequences, much like other adverse childhood experiences such as neglect or family violence. The results are so striking that bullying is now seen as a global public health problem with impacts on child, adolescent, and adult health.

What Is an Adverse Childhood Experience (ACE)?

An ACE is a negative or potentially traumatic event that occurs in childhood. ACEs can include physical, psychological, or sexual abuse, or neglect. It’s any prolonged or repeated experience that might undermine a child’s sense of safety and stability and, in doing so, lead to increased feelings of stress and social isolation.

The landmark ACEs study, a 1998 epidemiological review that looked at how childhood trauma can affect health later in adulthood, demonstrated that ACEs are directly correlated with mental health issues, substance abuse disorders, and chronic health problems such as obesity and cardiovascular disease.

Chronic bullying, or persistent physical or psychological abuse that may come from a family member or a friend, is considered an ACE. Like other ACEs, it can lead to overwhelming feelings of stress and isolation. Children who are bullied can develop anxiety, depression, and other mental health issues later in life, studies show. Bullying has also been linked to self-harm behaviors and even suicide. It’s a problem that scientists and public health experts now understand has a powerful impact on health, social, and emotional well-being.

How Common Is Bullying?

Between 15 and 22 percent of students between the ages of 12 and 18 experience some form of bullying, according to federal programs including the Department of Education’s 2022 Indicators of School Crime and Safety and the Center for Disease Control and Prevention (CDC)’s 2021 Youth Risk Behavior Surveillance System. It is a problem widespread enough that the CDC, as well as a variety of mental health advocacy organizations, have called for more programs to prevent it from happening in schools across the US.

Are There Different Types of Bullying?

Bullying can come in many different forms. The most common types of bullying involve being the subject of rumors or lies, being consistently belittled, or called names. Some people may also be bullied physically, by being pushed or shoved, for example, or having their property taken or destroyed.

Another form, known as cyberbullying, is a relatively new type of bullying that takes place digitally. People can be bullied over the internet, whether it’s by receiving negative emails, text messages, or online comments—or having rumors or lies spread to others via social media. Regardless of the type of bullying, it is something to take seriously, especially when the person being bullied is experiencing increased stress or negative feelings in response.

How Does Bullying Affect the Brain?

Since the first ACEs study was published, researchers have tried to understand why experiences like bullying can lead to such negative health consequences. Those studies have led to new insights into how bullying can lead to changes to the brain.

For example, the IMAGEN project—a European research consortium studying adolescent brain development—looked at the effects of bullying on young adults. About 30 percent of participants in the study said they had experienced chronic bullying, and they reported higher levels of anxiety than those who hadn’t been bullied. When the researchers looked at fMRI scans of the bullied individuals, they discovered structural differences in the brain in areas like the putamen and caudate, both linked to anxiety disorders. Other studies have shown that chronic bullying is also linked to white matter changes in the brain, which may make the person more susceptible to depression.

A more recent review of studies found an expanded range of impact—with changes noted in a variety of brain areas implicated in emotional processing, including the amygdala and prefrontal cortex. The review authors also hypothesize, given the wide range of areas affected, that bullying likely affects the way these different regions interact with one another, making it more difficult for victims of bullying to understand emotional cues and regulate their emotions.

Other studies, using animal models and human participants, suggest that chronic bullying leads to an increased release of stress hormones, like cortisol, especially in brain areas involved with reward-processing. Not only do those chemicals make you more reactive to stress, in general, but over time, they can change the circuitry in the reward centers, which can put people at higher risk of developing a substance use disorder after trying alcohol, cigarettes, or other drugs.

Finally, the stress hormones released during bullying can also affect the immune system. Those hormones can lead to increased inflammation, which has been linked to both depression and anxiety disorders, as well as medical conditions such as hypertension and obesity. When you put it all together, the chronic stress involved with the experience of persistent bullying can lead to structural and functional brain changes that increase the risk of developing both mental and physical health problems into adulthood.

Are the Cognitive Changes Permanent?

The good news is that the brain is “plastic”—the networks and circuits in everyone’s brains have the ability to change over time in response to their environment. Even if you have experienced bullying at one point or another in your life, that doesn’t mean you will necessarily develop ACE-related health problems. That said, if you are experiencing depression, anxiety, or are using drugs or alcohol in an unhealthy way, it’s important to reach out to your primary care provider or a mental health professional. They can help.

Does Bullying Harm the Bully?

Studies with animals demonstrate that those who are bullied tend to show increased levels of stress hormones, and over time, those bullied animals tend to be more aggressive toward younger, smaller animals. In addition to that, a 2013 JAMA Psychiatry study in people found both bullies and their victims showed a higher prevalence of childhood psychiatric disorders, including anxiety and depression. The study also showed that bullies—and not their targets—were at a higher risk for developing antisocial personality disorder later in life. That said, it is hard to be sure, because the vast majority of children who end up bullying others have been bullied themselves. It is a vicious cycle.

What to Do If You or Someone You Know Is Being Bullied

If you are being bullied, talk to an adult you trust: a parent, teacher, coach, or other important person in your life. Most bullying happens where other people can’t see it, so when you can shine a light on it by talking about it, you can do your part to help prevent it from happening again. Mental Health America also offers recommendations on how to respond in situations where bullying is taking place, whether it’s in person or online. For example, tell bullies to stop in a calm, clear voice; try to keep yourself surrounded by other people in situations where you are likely to be bullied; and never respond to online bullies. Your specific plan for managing the problem will likely depend on the type of bullying you or someone you care about might be experiencing.

Remember: Bullying isn’t something everyone goes through, or just a “normal” part of childhood. It can and does have lasting consequences. Whenever you can prevent it from happening, you’re helping prevent the development of bullying-related mental and physical health issues, too.

*Updated March 2024