After several tragedies in the past few years, bullying has gone from being considered a “soft” form of abuse to a high-profile issue in our society. With new research into the neurological and psychological effects of peer harassment and victimization, scientists strongly believe that the resulting emotional and stressful impacts on a teen’s brain could cause unforeseen short- and long-term effects.
The middle and high school periods are sensitive ones. Emotionally, individuals are struggling to find themselves and determine their place within their communities, and neurologically, their brain connections are still forming. Bullying at this developmental stage can certainly leave neurological scars: hormones can be thrown out of whack, connectivity in the brain can be stunted, and even the growth of new neurons can be impaired . The chronic stress experienced because of bullying during this time is so influential on an individual’s brain and emotional health that researchers have added it to the category of childhood trauma.
Martin Teicher, a neuroscientist at McLean Hospital in Belmont, MA, has long been examining this relationship between bullying and the brain in young adults . Teicher and his colleagues most recently studied a group of young adults who varied in how much verbal harassment they had received from their peers. Not surprisingly, what the scientists found was that the subjects who had been bullied reported more symptoms of depression, anxiety, hostility, and other psychiatric disorders than the non-victimized subjects. With these initial, confirming results, Teicher and his team decided to further explore the causes and effects of this relationship by conducting brain scans of 63 of their subjects. Surprisingly, the victimized individuals had, on average, about 40% smaller corpus callosums – the thick bundle of nerve fibers that acts as the bridge between the two hemispheres, and which is critical in visual processing, memory, and emotional balance, among many other functions. Moreover, the neurons within their corpus callosums had less myelin – the insulation layer around the axon that speeds the propagation of the action potential from one neuron to the next. While the molecular and cellular basis of this phenomenon is still unclear, these structural changes seem to be strongly linked to the higher rates of depression and anxiety that the bullied individuals experienced, and perhaps to their altered stress-processing mechanisms post-bullying.
In addition to causing structural damage, bullying is also implicated in causing emotional imbalances due to a disruption of hormonal homeostasis, especially for the hormone cortisol. Cortisol is an end product of the stress (fight or flight) response, and it is produced in the adrenal glands along with other stress hormones such as adrenalin. When a person experiences a threatening situation, their cortisol levels rise, causing the immune system to slow down and the learning systems to shut down, while their bodies prepare to manage the threat by either confronting the situation, or attempting to flee. Cortisol, like many other hormones, has far-reaching influence: by pushing the body into hyper-alertness and hyper-activity, it accelerates one’s heart rate, which propagates its further distribution throughout the body, and communicates with both the hypothalamus and the pituitary glands in the brain to further regulate this response.
Tracy Vaillancourt, a psychologist at the University of Ottowa, has been studying the effects of cortisol as a result of the stress associated with bullying on an individual’s emotional responses in a group of 12-year olds, where some of them had a history of being verbally harassed by their peers and others didn’t . After assessing their cortisol levels every six months, Vaillancourt noticed an alarming trend: the bullied subjects showed a substantial decrease in cortisol production compared to the control subjects; and, the bullied female subjects, compared to the bullied male subjects, showed an even lower level of cortisol. While it is still unclear why the bullied females produced less cortisol than the bullied males, the overall decrease in cortisol production points to the brain’s desensitization to cortisol. In other words, since the bullied subjects’ fear response was consistently activated, their bodies would need increasingly larger amounts of cortisol in order to sustain the same level of response. However, this resulting hypercortisolemia eventually becomes neurotoxic: over-stimulation for each subsequent fear response begins to cause neuronal cell death in associated brain structures, such as the hypothalamus, pituitary glands, and amygdala, which then leads to less cortisol production. Additionally, damage to these areas of the brain can cause a cascade of changes that affect attention, impulse control, sleep and dietary regulation, anxiety coping, verbal memory, and clear thinking.
Unfortunately, this is only the tip of the iceberg. When considering the effects of these changes in the long-term, the potential dangers become more variable and unclear. Since repeated bullying leaves an indelible print on a young adult’s developing brain, it may have long-lasting repercussions in adulthood. According to a large statistical study published in “Psychological Science” , adults who experienced childhood bullying were generally more likely to struggle to hold a regular job, to develop unhealthy habits such as smoking, to maintain poor social relationships, in addition to being at an increased risk for developing long-term psychiatric disorders, such as depression or anxiety. These findings, although not definitive, hint at just how damaging the consequences of bullying can be: emotional trauma may be just as harmful as physical injuries.
This interdisciplinary research between neurology and psychology is still fairly new, and as provocative as these findings are, they raise many more questions than they answer. On the neurological end, much is still to be determined at the molecular and cellular level. How and why do bullied males produce more cortisol than bullied females? What other previously unconsidered hormones could potentially be involved in this response? Moreover, it becomes difficult to differentiate cause and effect. Is it possible that certain teens are predisposed with certain biological and biochemical traits that somehow make them more likely to be targeted as a victim, or perhaps more likely to develop certain psychiatric diseases as a result? How is it that not every bullied child carries the repercussions of the traumatic events into adulthood? How can a child become more resilient to the effects of bullying?
While current research is still looking for clinical answers, our society has a responsibility. Studies have already shown that a young adult’s environment, which includes the home, school, and everything in between, is largely responsible for molding both their brain and their mind. Even though schools have established therapy programs and anti-bullying campaigns in order to alleviate the effects of, and discourage the act of bullying, peer harassment continues. More importantly, it carries a social stigma that, despite all of these efforts, is still ineffaceable. If we want any chance of changing the way bullying is handled, we need to start by changing the way it is perceived. Bullying, especially in today’s age, can no longer be considered as a “soft” form of abuse. With the rise of technology and cyber-bullying, peer harassment has become easier to accomplish, anonymous, and omnipresent. The school environment has become alarmingly more hostile than it was even a decade ago, and peer victimization has surpassed the school walls to infiltrate the home and become an all-pervading danger. Facebook, Tumblr, Instagram, and Twitter have become mediums for permanent and public humiliation, and even vectors for previously inexistent anonymous harassment. As a result, what was once a localized threat has become both impossibly difficult to anticipate and control, and has taken on an alarming and tragic face: lethality.
In June 2012, the Center for Disease Control and Prevention predicted that about one in twelve teenagers who had been victims of either cyber bullying or conventional bullying would attempt suicide . Considering that such a significant percentage of the future generation is emotionally and physically compromised, bullying needs to be treated as a serious public health concern.
 Teicher, Martin, Jacqueline Samson, Yi-Shin Sheu, Ann Polcari, and Cynthia McGreenery. “Hurtful Words: Exposure to Peer Verbal Aggression Is Associated with Elevated Psychiatric Symptom Scores and Corpus Callosum Abnormalities.” The American Journal of Psychiatry Vol 167, no. 12 (2010): 1464-471.
 Vaillancourt, Tracy, E. Duku, D. Decatanzaro, H. MacMillan, C. Muir, and LA Schmidt. “Variation in Hypothalamic-pituitary-adrenal Axis Activity among Bullied and Non-bullied Children.” Aggressive Behavior Vol 34, no. 3 (2008): 294-305.
 Wolke, Dieter, William Copeland, Adrian Angold, and E. Jane Costello. “Impact of Bullying in Childhood on Adult Health, Wealth, Crime, and Social Outcomes.” Psychological Science Vol 24, no. 10 (2013): 1958-970.
 “Youth Risk Behavior Surveillance — United States, 2013.” Center for Disease Control and Prevention: Morbidity and Mortality Weekly Report Vol 63, no. 4 (2014).
Image Credit Accessed March 22, 2015. http://upload.wikimedia.org/wikipedia/commons/b/bc/Rebecca1917version.jpg.
Natalie Petrossian is a third-year student at the University of Chicago majoring in the Biological Sciences and specializing in Neuroscience. Follow The Triple Helix Online on Twitter and join us on Facebook.