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Section 1

Violence is an unfortunate part of our everyday life. It can be seen leading off the news every night, from extreme stories of war, to sad stories of family tragedies. With the repetitive nature of violence as well as escalating costs in order to prevent it, society searches for answers of how to prevent violence. In order to find an answer of how to prevent violence, we must first find out why violence happens. Throughout much research, there has been no definitive answer for one underlying reason for violence to happen. We have come to an agreement that there are many possible reasons, correlations, and causes for violence, and they are all related. In order to start to find a solution to violence, we must break it down to small sections of correlations. One such section we investigate is serotonin, and how it is related to violence.

Serotonin is a neurotransmitter in the human mind. The scientific name for serotonin is 5-hydroxytryptamine, and it is a messenger for nerve impulses to travel between synaptic gaps in the brain (Alvarez and Bachman, 2008, pg. 35). Serotonin is needed for messages in the brain to transmit and be processed, and the messages can’t make it across the gap without serotonin. One of the aspects of violence that serotonin has been linked to is impulsivity of aggressive acts (Alvarez and Bachman, 2008, pg. 35). If a person has low serotonin, they are more likely to engage in aggressive acts because of their inability to control those aggressive impulses (Alvarez and Bachman, 2008, pg. 35). Although there is no evidence that low levels of serotonin in the brain causes violence, it has been correlated to findings that people with low levels have a harder time stopping to think about their actions before engaging in violence (Alvarez and Bachman, 2008, pg. 35).

Studies have been done to test this theory of serotonin being linked to violence. In the study performed by Retz, Retz-Junginger, Supprian, Thome, and Rosler (2004), the authors attempted to support a link between the serotonin (5-HT) function and impulse control and violence. The study was performed on a sample of 153 adult males, 132 of which were criminal defendants. The sample was split into a violent and nonviolent group based on history of criminal charges. After researching the groups, the authors concluded that there was support between lowered or disturbed serotonin function and violent and aggressive behavior. The authors also showed a link to impulsive behavior, which is related to aggressive and violent behavior. These findings help support previous research that violent behavior and impulsive behavior is correlated to having low serotonin levels.

Another study that was performed to investigate a correlation between low serotonin levels and violent behavior was performed by Courtet and colleagues (2001). In this study the authors attempted to support the correlation. In order to examine this correlation, the authors used those that attempted violent suicide and nonviolent suicide. The study used 51 patients from a psychiatric department after a violent suicide attempt, and 139 people who have not attempted suicide. The study supported the hypothesis that deficient serotonin levels are related to the violent suicide attempters. This supports the idea that low serotonin levels are related to violent and impulsive behavior.

Another study that links low serotonin levels with violence was performed by Siegel, Bhatt, Bhatt, and Zalcman (2007). In this study, the researchers examined many different behavioral characteristics and how it relates to violence. Some of the ways that serotonin has been studied were manipulations of brain serotonin levels, and pharmacological manipulations of brain serotonin levels. In order to manipulate serotonin levels without pharmacology, research has used dietary manipulations such as tryptophan. The results of this study were that men were more aggressive after tryptophan depletion. This supports the idea that depletion on tryptophan, which leads to lowered serotonin, increases the likelihood for violence. The study also investigates the manipulation of pharmacology, such as fluoxetine, to decrease aggressive behaviors. The results of this manipulation showed that aggression was decreased with fluoxetine treatment. This not only shows that lowered serotonin is correlated to violence, but increasing the depleted serotonin can decrease aggressive acts.

With many previous studies supporting the hypothesis that low serotonin levels are related to violence, researchers have begun attempting to find out how best to test for serotonin levels. In the study by Lande (2003), the author attempts to support a newer way to test serotonin levels. As stated previously, serotonin is located in the synaptic clefts in the brain. In order to test for serotonin levels with less obtrusive methods than going into the brain, researchers have begun trying new methods of testing. One of the ways for testing is by whole blood serotonin. In order to test for central serotonin, the authors would use whole blood serotonin, an indirect measure. Findings were that aggressive participants have a higher level of whole blood serotonin. In order to support this measurement, the author used this test on defendants in murder trials. These participants were tested to make sure other variables such as drug use and special diet would be controlled. The participants were then compared to a sample not being charged with murder. Results from this study were that violent men’s whole blood serotonin levels were .41 standard deviations higher than the control sample. This supports the hypothesis that there would be a noninvasive test to measure serotonin levels for predicting correlation to violence. This could help future policy makers implement laws or rulings in the future. It would determine which people would have lower serotonin levels than the normal population.

Section 2

As stated previously, violent acts are an unfortunate part of everyday life. We see headlines so often in the news that it becomes unimportant or a normal occurrence. One such story happened on May 16th, when a U.S. soldier killed five fellow soldiers in Iraq. The soldier’s name is Sgt. John Russell, a 44-year old from Sherman, Texas. Sgt. Russell is currently in his third tour of Iraq, and has also been deployed to Bosnia and Kosovo. The decision for the killings all began when a normal occurrence, or a situation that a normal person would consider small, began a sad series of events.

Sgt. Russell was referred to a counselor for “unspecified words and actions”, and had his weapon taken away. He was then escorted back to his living quarters by a fellow soldier. Sgt. Russell seized control of the soldier’s weapon a few hours later, stole a vehicle, and drove back to the clinic where the events began. Sgt. Russell then killed five soldiers at the clinic, two worked at the clinic and three that just happened to be there. Sgt. Russell wasn’t able to take the news that he wasn’t allowed to carry a weapon and needed counseling, and decided to fix this situation with violence.

Section 3

As this event just occurred, we are unsure of the root cause of Sgt. Russell’s actions. The fact of the matter is that Sgt. Russell was relieved of his duties and he stole a weapon and killed five people. Although we are unsure of Sgt. Russell’s serotonin levels, we can come to an agreement that this event seems to have impulsive action related to violence. Sgt. Russell could have waited for counseling, hearing the results before acting. Even if the results of the counseling were negative, Sgt. Russell could have taken any number of different routes to appeal any decisions on his career. Instead, Sgt. Russell did none of these well thought out actions. Sgt. Russell was frustrated and angry, and he decided to act in violence in order to remedy these feelings.

Previous research on serotonin could have been applied in order to have prevented this act of violence. As stated by the previous research of Retz, Retz-Junginger, Supprian, Thome, and Rosler (2004), low serotonin levels have been linked to impulsivity. If the Army were to use this information, they could have screened people to prevent possible random acts of violence. With the knowledge that low serotonin levels are linked to impulsivity, the army would have an educated understanding of who would be at greatest risk of unwanted violence around weapons. This link to impulsive action was also supported by a study performed by Courtet and colleagues (2001). As stated previously, individuals who attempted a more violent suicide were shown to have lower serotonin levels as well. If the army decided to test those that have low serotonin levels, they might have been able to prevent this event from occurring. The U.S. Army is able to decide whether to implement a blood sample for all new recruits. All soldiers are subject to any regulations that the U.S. Army decides to implement, so preventative measure could have been made. If the information found in Lande’s (2003) study was used to recognize low serotonin levels, preventative measures could have been used. In that study, a less invasive was of testing for low serotonin was supported. This method, or whole blood serotonin levels, is an easy way to record serotonin levels without having to record the amount of serotonin in the brain. The Army could have required this test in order to recognize who is at greatest risk for impulsive violence.

The underlying problem is that the U.S. Army wants, and needs to have violence in their profession. Although this paper must accept the fact that violence is desired to be a member of the army, a soldier would be expected to act when the time is right, and not impulsively. In order to curb any possible impulsive violence the army might use the results from the study by Siegel, Bhatt, Bhatt, and Zalcman (2007). In this study, the authors manipulated diet and pharmaceutical drugs to try to manipulate serotonin levels. The Army could have used this information after screening for those with low serotonin levels. Once soldiers are screened, those with genetically low serotonin levels could be either placed on a high tryptophan diet or on a drug therapy in order to increase serotonin output to normal levels. This would decrease the amount of impulsive violence that might occur in the Army.

Section 4

Although serotonin levels could be linked to some acts of violence, it unfortunately is not a reason for all acts of violence. One such incident that low serotonin levels in not relatable is the events that occurred at Columbine High school on April 20th, 1999. On that day, two high school students planned a massive attack on their school. According to investigators, the students were planning the best course of action for over a year in order to obtain the highest death toll possible. The students made hundreds of bombs and attempted to blow up and kill all the students in the quad as well as the library and cafeteria. The students learned bomb-making techniques from the Internet and worked for years in order to buy the bomb ingredients and guns. Although this plan did not go through as intended, it shows great diligence and thought.

This is opposite of the violence that is linked to low serotonin levels. The type of violence that is linked to low serotonin levels is impulsive and unplanned. The perpetrators of Columbine were not bullied and just snapped, but rather planned it for a long time. There was no one moment that the perpetrators acted without thinking, but rather the exact opposite. The perpetrators put great thought and planning, and the only impulsive moment in the series of event occurred after the bombs didn’t go off. Although shooting the students as the main attack was a slightly impulsive action, the two killers already planned to shoots students as they ran away from the explosion. The only impulsive moment was to decide to just shoot rather than go back and build more bombs for another attack at a later date.

In conclusion, taking serotonin levels would not solve all of the violent behavior we see today. Although we have seen there is a course of action to both take serotonin levels in a noninvasive manner and to treat those with low serotonin, this is not the only reason for violence. We have seen in the acts of Columbine that not all violence is impulsive. Some acts of violence are well planned out, and might take place years after the initial thought was first conceived. Due to this example, we must realize that taking serotonin levels in not the end-all answer to how to prevent future violence from occurring.


Alvarez, A., & Bachman, R. (2008). Violence: The Enduring Problem. Los Angeles: Sage Publications.

Courtet, P., Baud, P., Abbar, M., Boulenger, J., Castelnau, D., Mouthon, D., et al. (2001). Association between violent suicidal behavior and the low activity allele of the serotonin transporter gene. Molecular Psychiatry, 6(3), 338-341.

Lande, R. (2003). Whole blood serotonin levels among pretrial murder defendants. Journal of Psychiatry & Law, 31(3), 287-303.

Retz, W., Retz-Junginger, P., Supprian, T., Thome, J., & Rösier, M. (2004). Association of serotonin transporter promoter gene polymorphism with violence: Relation with personality disorders, impulsivity, and childhood ADHD psychopathology. Behavioral Sciences & the Law, 22(3), 415-425.

Siegel, A., Bhatt, S., Bhatt, R., & Zalcman, S. (2007). The neurobiological bases for development of pharmacological treatments of aggressive disorders. Current Neuropharmacology, 5(2), 135-147.

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