The Keenan Blog

Timely and informative posts written by our experts.


Bullying Changes the Brain

April 30, 2019 by Kathy Espinoza

The devastating consequences of bullying are well documented, and this has led to continuing efforts to halt these harmful behaviors. Research on the long-term impacts both for targets and instigators has brought important insights to the forefront, emphasizing the importance of this issue. Recently, studies have demonstrated that bullying can result in permanent chemical and physical changes in the brain (See resources below). Such alterations can be carried by an individual from childhood into their adult years with the potential for lifelong mental and physical problems, along with social, financial and employment difficulties.

Children who are targets of bullying on an ongoing basis often develop an overactive stress response that persists even at times they are not threatened. As they reach their teen years, the brain chemistry causing this stress response can cause them to become more impulsive, aggressive and permanently anxious. Such stress can also decrease the blood flow to critical areas of the brain which affect depression, irritability and impairs attention. Physiologists studying those suffering the psychological abuse of bullying found that certain structures of their brains were up to 40% smaller than expected, with the consequence of manic mood shifts and difficulty with social judgment. Long-term studies of bullied individuals revealed that physical and psychological effects of frequent bullying still affected them 40 years later.

Individuals who had been both bullies and targets of bullying seem to exhibit the worst outcomes for future mental health, financial distress and facing the challenges of parenthood. Bullies also carry a decreased capacity for empathy into adulthood. A University of Michigan study compared current college students with those of the 1970s and found that young people of today are 40% less empathetic. These findings have implications well beyond the playground and classroom.

Additional studies have shown certain changes in brain chemistry induced by bullying have health impacts beyond the brain. Individuals under the constant anxiety and stress of persistent bullying have higher levels of a brain chemical indicating low-level inflammation in the rest of the body. This kind of inflammatory response is closely related to cardiovascular disease, imbalances of metabolism, and immune disorders.

The findings from this wide range of research show that bullying is more than just bad behavior. It’s bad for our mental and physical wellbeing. It creates serious problems extending far beyond childhood and could contribute significantly to many socioeconomic problems in our communities. Addressing and preventing bullying in our schools and neighborhoods will not only make it safer for our children today; it’s also an investment in their future.

Additional background on Bullying and the Brain:

Bullying alters brain structure, raises risk of mental health problems
(National Center for Education Statistics and Bureau of Justice Statistics)

The Science of Bullying
(research from Children's Hospital Los Angeles and the University of Southern California Keck School of Medicine)

Long-Term Effects of Bullying
(Wolke D, Lereya ST. Long-term effects of bullying. Arch Dis Child. 2015;100(9):879–885. doi:10.1136/archdischild-2014-306667_Wolke D, Lereya ST. Long-term effects of bullying. Arch Dis Child. 2015;100(9):879–885. doi:10.1136/archdischild-2014-306667)


About Kathy Espinoza
Kathy is Keenan's ergonomist and conference speaker, authoring numerous articles on ergonomics, injury prevention and management issues that have an impact on Keenan clients.