A. When violence causes tragedy, the initial response is usually a knee jerk reflex to blame and seek vengeance. After this initial impulse to vent our frustration, it leaves us with an unsettled feeling as we ask – how did it really happen? Although aggression is a fundamental part of human nature, violence and homicide are not. In the aftermath of tragedy we attempt to comprehend this dark side of human nature. When the perpetrator survives, they are assessed from the perspective of sanity, responsibility, blame, punishment, and rehabilitative potential.

It is often difficult to accurately assess these categories. The identified perpetrator may also be a victim. They may not be clearly sane or insane. Responsibility and blame may be very complex issues. The preponderant view that someone declared sane has total criminal responsibility, while someone labled sane has none, is overly simplistic. A continuum of purposeful and knowing free will is more accurate, and the legal system needs to reflect this in assessing the degree of criminal responsibility. Punishment may or may not have deterrent or corrective value. In some instances, the threat of punishment encourages both a masochistic perpetrator, and a perpetrator who recognizes that incarceration may be an improvement in the quality of their life. Rehabilitative potential may be impossible to predict in view of our rapidly advancing mental health treatment capability. Categorizing the perpetrators as guilty, and deserving punishment often gives an artificial sense of closure.

When we view a criminal act as merely the result of an act of "badness" rather than illness, it prevents us from looking further into the multitudes of dynamics that contribute to crime, which in turn hinders our ability to impact the forces that lead to crime. Instead, we frequently blame and punish, and our prison population grows. An excessive reliance upon such an approach is comparable to the "Just Say No" anti-drug campaign.

Statistics show that youths arrested for homicides increased 90% between 1987-1991. It cannot be as simple as just a lot of "bad" young people. It is often said that a plane does not crash as a result of only one failure. The crash is a result of a series of failures. We need to look closely at all the forces that interact to lead to violence. From evaluating many potentially violent and post violent situations, I have found the following approach to be useful. Since violence is a very complex issue, it can best be understood by using a multisystem model which incorporates the multitude of factors that contribute to violence. It is important to realize that no single thing alone causes of violence, but instead it is a unique interaction of multiple determinants that cause violence.

For example, one Danish study demonstrated that neither obstetrical complications or maternal rejection alone were associated with future crime, but the combination of the two were associated with a significantly increased risk for later violent offenses. Likewise, genes alone rarely, if ever, cause violence, however, genes interacting with specific life situations can play a contributory role. While using the multisystem interactive model, it is helpful to look at three major considerations – predisposing factors, triggering events and a failure of the normal deterrents to violence.

There are many predisposing factors which span the entire spectrum of all the bio-psychosocial forces that impact human behavior. However, most commonly these can be reduced to three major categories – neurological impairment, a history of abuse, and social isolation. One study found that 100% of death row inmates were neurologically impaired. Sometimes the impairment is obvious, while at other times it is more subtle and difficult to detect.

With new technical ability to study the brain, we are now better able to study altered physiological and neurological patterns associated with criminal aggression. For example, criminal behavior shows a statistical correlation with low levels of physiological arousal; such as low resting heart rate, low arousal measured by EEG, and low levels of skin conductance activity, fearlessness, and overall decreased sensitivity to the world around them.

To briefly review the physiology of the brain, there is a hierarchy of functioning within the central nervous system(CNS), which has developed through evolution. When we go from the most advanced to the most primitive areas of the brain, the hierarchy consists of the prefrontal cortex, other cortical regions, para limbic associative areas, the limbic system, and the brain stem and hypothalamus. These centers function together with many feed forward and feed back pathways that are both stimulatory and inhibitory. Injury to a higher center can result in a dysfunction or a loss of a function. Injury to an inhibiting pathway will cause a decline or an inability to inhibit that function. As a result, brain injury leads to a decline in our ability to fine-tune our adaptive abilities in an effective manner.

In the case of aggressive functioning, injury can lead to apathy (a failure of stimulation) and/or aggression (a failure an inhibition, modulation, or association). Since circuits controlling aggression are often parallel with sex and feeding, we often see aggressive disorders in combination of sexual dysfunction and eating disorders. Different patterns of brain injury result in different patterns of symptoms.

Neural injury impairs the physiological capacity for bonding is particularly significant in contributing towards autistic and antisocial tendencies. This has been associated with temporal lobe dysfunction. Stroke, tumors, radiation injury, carbon monoxide poisoning, lupus, MS, head injuries, herpes, shigella, and other infections have been demonstrated to cause temporal lobe injury and bonding impairments. Primate experiments have demonstrated that infection of the trigiminal (5^th cranial nerve) can progress to involvement of limbic temporal lobe structures that are particularly significant in interpersonal bonding. This is only one of several entry routes into the CNS by microbes.

Impulsive, explosive anger is frequently associated with frontal lobe dysfunction. One teen-ager with frontal lobe dysfunction I evaluated for rape and murder had such poor impulse control that he expressed his annoyance with the judge by attempting to attack and strangle him during his trial. Many head injuries cause injury to the tips of the frontal and temporal lobes. This combination of frontal and temporal lobe injury, in some cases, contributes to an impairment of both impulse control and bonding capacity, which increases aggressive potential.

Compulsive aggressiveness is associated with an overactivity of the cingulate gyrus. This finding supports the view that such individuals have difficulty with mental flexibility, shifting their thoughts and motivation. Many other types of neurological impairments which prevent health adaptive functioning may also contribute to dysfunction associated with violence. These findings include low IQ, particularly low spatial IQ; decreased frustration tolerance; obsessive compulsive disorder with intrusive thoughts, images, and compulsions of a violent nature; increased startle reflex; hypervigilance, sensory hyperacusis; impaired perception of reality; paranoia, delusions, hallucinations; poor insight; and a failure of higher powers resulting in an emergence of more primitive behavior. It is again important to emphasize the presence of any of these findings does not necessarily cause violence but instead different combinations and interactions contribute to violence.

It is my opinion that we have not given adequate attention to the role of infectious disease in causing dysfunction that contributes to violence. I have evaluated a number of cases in which infectious disease affecting the CNS played a major contributory role in violence, suicide, homicide, combined homicide/suicide, and other felonies and crimes.

It is my hypothesis that certain regions of the world that are more endemic to infections that affect the brain are associated with a higher incidence of violence and war. For example, the Balkans. Throughout history, soldiers returning from war zones often displayed unusual post war syndromes. It is possible that infectious diseases which contributed to the war also contributed to causing the post war syndrome in the veterans. We need to consider the possibility that wars may be more effectively fought with medical care, vaccines, and antimicrobial treatments rather than military intervention, guns, and bombs.

If anyone looks carefully at the facial expressions of the teens who committed the school shootings, most of them had facial asymmetry which indicated the presence of Bell’s palsy (7^th cranial nerve). This finding usually indicates an infection has affected the nervous system. Although Bell’s palsy is a common finding in the general population, the prevalence of this finding is much greater in these youthful offenders. This suggests an infection of the CNS may be a contributing factor in these school shootings.

 A second major contributing factor is a history of neglect and/or abuse which can contribute to a greater possibility of impaired social bonding, excessive guardedness, impulsivity, and greater negative reactivity. A common dynamic in perpetrators of the most violent acts is a prior history of both neurological impairment and abuse. Sometimes the neurological injury precedes the abuse, sometimes they begin at the same time, and sometimes the abuse precedes the neurological injury. The presence and interaction of both can contribute to a vicious cycle of increasing social isolation and hostility.

Social isolation is another very major predisposing factor which precedes violence. Although there are many different explanations most perpetrators have a history of poor social adjustment. On close scrutiny, many offenders do not possess healthy sexual relationships. Another major predisposing factor is substance abuse which can further contribute to the isolation and other issues already discussed. Other predisposing factors include belonging to a gang; access to firearms; larger physical stature; a history of torturing animals, fire setting, or prior criminal arrests.

As Mao once stated, "Power is in the barrel of a gun." Individuals who feel disempowered, some who feel ineffective and helpless think of violence as a means of acquiring the power, notoriety, or attention they often lack.

In adolescents, role models are particularly significant. Many youths who commit violence identify with violent role models such as – "Natural Born Killers ", "The Terminator", and notorious criminals. They commonly listen to music with themes of alienation and violence, such as the music of Marilyn Manson. The availability of violent themes in the mass media appears to be a contributing factor. One isolated area of Canada had a low incidence of violence until there was access to television We now are seeing a generation of youths who grew up with violent video games, a greater incidence of violence in movies and TV, and greater access to violence on the Internet. Some perpetrators are obsessed with different movies and or music prior to the violent behavior.

No single risk factor correlates 100% with violence. Even when many predisposing factors are present, we possess an ability to compensate and still adapt in a healthy manner, but out compensatory abilities are limited.

Triggering factors contribute to provoking violence in someone who is vulnerable to these particular triggers. Examples include different types of acute stress, a perception of threat, jealousy, competition, impairment from substance use, obsession, psychotic delusions, post traumatic flashbacks, hopelessness, a lack of pleasure from life, and suicidal intent.

There are a multitude of deterrents which normally prevent violence even when risk factors exist. Some of these deterrents are programmed genetically within as by evolution. Our empathy for another person is the greatest deterrent. In most instances, a healthy person cannot look into the eyes and face of another person and commit a violent act. There are a multitude of deterrents to violence throughout our nervous system, psyche, and body not all of which are well understood. A stable society also has a number of deterrents to violence, including a stable family, the community, and other formal social structures. These include health care systems, religious organizations, educational systems, governmental systems, and legal systems. Failure in any of these areas can increase the risk of violence. The abysmal failure of managed care to provide adequate mental health care for severely disturbed youths has been a major problem in recent years. A technology exits to prevent many forms of violence, but there are many barriers which prevent access to and implementation of this higher level capability.

We can conceptualize violence into two major categories – defensive and predatory. Some violence shows elements of both. Defensive aggression is more easily understood. It occurs in response to a perception of threat. Often there is a counter provocative effect between the perpetrator and the potential victim (70% of homicide victims are intoxicated at the time of the homicide). The vicious cycle of aggressive counter provocation accelerates the level of hostility and magnifies the violent potential. In contrast, predatory aggression such as, serial killing, mass murders, spree killings, and sexual sadistic murders, are more predatory, and more difficult to understand. Humans are controlled predators by nature. However, predatory aggression is normally controlled and adequately restrained by higher power. The greatest safeguard against predatory aggression is the capacity to form healthy, empathetic bonds with others. When there is a failure of healthy bonding, sexual motivation and the drive to feel connected to another person may be expressed in a bizarre manner. Mild impairments may be expressed as subtle forms of sadomasochistic behavior, while more severe pathology is manifested as sexual sadism, pedophilia, necrophilia, and cannibalism. One form of homicide, neonaticide is associated with a failure to bond, his unique dynamics, and should be viewed in a specialized conceptual framework.

To better understand violence we need to closely look at ourselves in the mirror. There is a violent potential within human nature itself which is not always restrained by our higher power and the influence of civilization. We must recognize the aggressive potential which exists within us and all the forces which encourage or deter its appearance. An eventual goal is improved prevention and better access to effective intervention before the crime. Mental health technology needs to exceed weapons technology.

We are in the last year of the Decade of the Brain.  Our understanding capability is proceeding foreword at a rapid pace. We need to keep mental health as a high national security priority. Society in the millenium to come many look back with disdain at our current excessive reliance upon the blame/punish approach to deal with seriously disturbed offenders with the same amazement that we view the approaches of the last millenium.

Robert C. Bransfield, M.D.