At year-end 2019, the total prison population in the U.S. numbered a staggering 1,430,800. And of these prisoners, 8% were serving time for a violent offense, according to the
Bureau of Justice Statistics. What makes some people violent? If you’re like most people, you may think it’s due to poor parenting, a character flaw, or just being a “bad” person. Brain imaging shows there may be another reason.
Mounting scientific evidence shows that
traumatic brain injury—even a mild one that doesn’t cause loss of consciousness—can lead to aggression or violent behavior in some people. Someone who has experienced a TBI may erupt with anger with little provocation. Something that seems inconsequential may set them off, and the severity of their reactions can range from irritability to verbal abuse to physical assault. Rather than writing off these individuals as bad people, it’s important to look at what’s happening in their brain.
The Link Between Head Trauma and Aggression
Aggression following head trauma is more common than you might think. Research in
The Journal of Neuropsychiatry and Clinical Neurosciences conducted a study in 2009 to evaluate 67 individuals who had suffered a TBI for the first time. Within 3 months of the injury, over 28% of them displayed post-TBI aggression (primarily verbal). In most cases, the aggression was associated with the onset of depression among other psychosocial problems.
Among violent inmates, the prevalence of TBI is even higher. In a
2020 study in
Frontiers in Psychiatry on violent offenders, over 77% reported experiencing one or more head injuries in their lifetime. Aggressive antisocial behaviors and
substance use disorders were more common in those prisoners with a prior TBI.
Other findings in
The Journal of Neuropsychiatry found that people with intermittent explosive disorder, a condition associated with impulsive aggression, are significantly more likely to have experienced a mild TBI compared with healthy people or those with psychiatric disorders. Such was the case with a
5-year-old boy who stabbed 3 members of his family over a juice box.
Although that case made national headlines, there are many more cases of domestic violence that go unreported and unseen. And expressions of violence can be quite frequent in some people. In a fascinating study in
Brain Injury involving 46 people in a TBI neurobehavioral program, the researchers noted 3,914 acts of aggression over a two-week period. Of those acts, 443 were physical assaults while the rest were verbal.
Post-TBI Self-Harm and Suicide
The violent behavior some people experience after a concussion isn’t always directed at others. In some cases, it manifests in the form of hurting oneself. Research in the
American Journal of Public Health shows that head injuries increase the risk of suicide. And findings in a
2009 study reveal that
self-harm is more prevalent in those with a prior head injury. Experts suggest that feelings of depression that emerge or worsen after a TBI can increase the risk of self-harm and
suicidal behaviors.
Related Consequences Associated with Head Injuries
A wealth of research shows that TBIs also increase the risk of
depression, substance use disorders,
ADD/ADHD, and more. These issues may indirectly contribute to violent behavior. For example, depressive symptoms are linked to an increase in the incidence of self-harm as you saw above. Drug or alcohol abuse impair thinking and judgment, increasing the chances of making poor decisions in relation to aggressive or violent behavior. ADD/ADHD, which is characterized by problems with impulse control, is associated with a tendency to act without thinking. Head trauma has also been linked to an increased risk of incarceration. In the U.S., 25-87% of all inmates say they have suffered a TBI compared with 25-38% in the general population.
How Even Minor Head Injuries Negatively Impact the Brain
Brain SPECT imaging, a well-respected technology that shows how the brain functions, reveals that suffering a TBI can have serious impacts on the brain. Amen Clinics has built the world’s largest database of functional brain scans related to behavior—over 170,000 scans and growing. These SPECT scans show that head injuries decrease blood flow to important brain regions that have been damaged. Some brain areas that are commonly impacted due to head trauma include:
Frontal Lobes
The brain’s frontal lobes are involved in impulse control, judgment, empathy, and more. When there is damage in this area it can increase the risk of aggression and violent behavior. Many people may think about committing violence or saying something abusive, but the vast majority of us work through the potential consequences of doing so and choose not to act out on those dark thoughts. When the frontal lobes are underactive, there’s a greater chance of acting out impulsively. In addition, decreased activity in the frontal lobes due to damage from a TBI is associated with a lack of empathy, meaning people don’t take others’ feelings into consideration. Instead, they blurt out hurtful things or lash out physically.
Temporal Lobes
The temporal lobes, located on either side of the eyes and underneath the temples, are involved in mood, emotional stability, and learning. Abnormal activity in this important brain region is associated with temper problems, anger, and unpredictable moods and behaviors.
Pituitary Gland
The pituitary gland is a pea-sized structure that lies in the back of the brain that is involved in hormone production. The pituitary gland sits in a bony area of the skull called the sella turcica, making it vulnerable to damage, especially from whiplash injuries. Damage to the pituitary gland can result in hormonal imbalances that increase the likelihood of a wide range of symptoms, such as anger, temper outbursts, depression, and more.
Where’s the good news in all this? People who display aggression or act out violently may have a
hidden brain injury. And there is hope for healing a damaged brain. When you put the brain in a healing environment, it can boost brain health and improve emotional stability and behavior.
Violence, aggression, head injuries, and other brain health issues can’t wait. At Amen Clinics, we’re here for you. We offer in-clinic brain scanning and appointments, as well as mental telehealth, clinical evaluations, and therapy for adults, teens, children, and couples. Find out more by speaking to a specialist today at 888-288-9834 or visit our contact page here.
