The Correlation Between Death Row Inmates and Schizophrenia

This paper reflects the research and thoughts of a student at the time the paper was written for a course at Bryn Mawr College. Like other materials on Serendip, it is not intended to be "authoritative" but rather to help others further develop their own explorations. Web links were active as of the time the paper was posted but are not updated.

Contribute Thoughts | Search Serendip for Other Papers | Serendip Home Page

Biology 202

2006 First Web Paper

On Serendip

The Correlation Between Death Row Inmates and Schizophrenia

Claude Heffron

Since I was very young and began to hear talk of the death penalty, I always intuitively believed that most people who commit crimes that are punishable by death are not normally functioning people. Scientific research supports my early belief that there is some kind of link between violent criminal behavior and mental illness. Of mental illnesses, paranoid schizophrenia seems to be one of the most prevalent among death row inmates. Schizophrenia influences the features of the brain, which causes schizophrenics to behave in ways that are seen as deviant by the rest of the population. While many researchers maintain that there is no connection at all between violence and schizophrenia, they often concede that schizophrenic patients are more likely to abuse alcohol and drugs, which often contributes to violent behavior (10).

Schizophrenia has been labeled one of the ten most debilitating diseases by the World Health Organization (12). The 1% of adults who suffer from schizophrenia may experience "positive symptoms" such as hallucinations, delusions, thought disorders, or disorders of movement; "negative symptoms" like speaking infrequently, an inability to sustain activities, or a lack of pleasure; and "cognitive symptoms" including short attention spans, poor executive functioning, and difficulty with memory (10).

An Australian study on schizophrenia declares that schizophrenics are three to five times more likely to commit violent crimes than non-schizophrenics. In contrast, another study over a thirteen year period reveals that fewer than .2 percent of schizophrenics committed murder (9). This evidence shows a correlation between death row inmates and schizophrenia, but it cannot be assumed that schizophrenia necessarily causes people to exhibit criminal behavior.

Causes of schizophrenia are attributed mainly to genetics, but environmental influences are also factors in the development of this disorder (10). So what exactly makes schizophrenics different? The National Institute of Mental Health proclaims that imbalances in neurotransmitters, specifically dopamine and glutamate are observable in schizophrenics (14). People with schizophrenia have distinctly different features in their brains when compared to non-schizophrenics. For one thing, they have 25% less gray matter, when measured in volume, than non-schizophrenics in the frontal and temporal lobes of the brain. According to certain studies, schizophrenics also have enlarged amygdalas and enlarged lateral ventricles(5). In a study at King's College of London, researchers found that the difference in brain size that is evident in schizophrenic patients was even more pronounced in those schizophrenics with a history of violent behavior (1).

Given what is known about the differences in the brains of schizophrenic patients, it is possible to hypothesize that features of the brain could contribute to the violent criminal behavior that is occasionally demonstrated by schizophrenics. Various methods, such as CAT scans and MRI imaging, show that there is a decreased frontal lobe size in schizophrenic patients. This can certainly explain why schizophrenics have difficulty focusing and difficulty with memory. The frontal lobe also has numerous effects on personality, and deficiencies in it could potentially result in abnormal behaviors such as irritability or aggressive acts (13), including violent criminal acts

One notable effect of smaller temporal lobes in schizophrenics is the inability to classify things. Malfunctioning temporal lobes can lead to memory, mood, and drive problems (14). Furthermore, it is possible that schizophrenics' ineptitude with classification could make understanding the difference between "right" and "wrong" or legal and illegal very challenging.

Lateral ventricles distribute cerebral spinal fluid throughout the brain, distributing nutrients, ridding the brain of wastes, and cushioning the brain (2). The reason that schizophrenics have enlarged lateral ventricles, and the effects of this feature are largely unknown, but as with all parts of the brain this region is very likely to effect behavior.

The New York Academy of Sciences theorizes that the unusually small size of the amygdala in schizophrenic patients may help explain their disorder (11). They theorize that this characteristic of the amygdala may lead to fear and anxiety, potentially causing paranoid behavior. Another variation in the limbic system is a high concentration of both D3 and D4 (dopamine) receptors that could be a cause of schizophrenics' inability to inhibit and express emotions (4).

People with mental illnesses are much more likely to use or abuse alcohol or drugs. In fact, as much as 50% of the mentally ill population suffers from a substance abuse problem(5). There are several possible reasons why schizophrenics are likely to end up abusing substances. Some use alcohol or drugs to reduce anxiety and fear. Another explanation is that social stigmatization can force the mentally ill into economic situations that put them in frequent contact with substance abusers.

The link between schizophrenia and violence is not universally agreed upon. Some scientists do not believe that the mentally ill are any more likely to commit violent crimes than the general population. Others have found much anecdotal and statistical evidence indicates that a link between mental illness and criminal behavior does exist.

Schizophrenia may be the most dominant in the news, but people with all different types of mental illness and brain trauma often end up on death row. Dr. Dorothy Lewis of New York University did a study of juvenile convicts and found that of 14, all 14 had experienced brain trauma, 12 had been abused by their parents, and five had been sodomized by relatives (6). ACLU reports that since 1983, at least 60 mentally ill people have been executed, although this most likely reflects serious underreporting as quite a number of mentally ill prisoners do not disclose this information (7).

A good example of anecdotal evidence indicating a link between schizophrenia and violence is the case of James Blake Colburn. Colburn was executed in 2003 in Texas. A paranoid schizophrenic who also suffered from post-traumatic stress disorder, James Colburn had a long history as a drug user and had attempted suicide several times. He seems to have been having a hallucination when he claimed in court to have heard voices telling him that the way for him to get back into prison was to murder someone. Colburn was sedated for his trial, convicted, and sentenced to death (12).

Assuming that brain and behavior directly influence one another, it is inhumane to execute mentally ill criminals. People with brains that are far different from those of the majority of the population can be expected to exhibit very different behaviors, including the ability and desire to commit violent crimes. The National Alliance for the Mentally Ill states that "the death penalty is never appropriate for a defendant suffering from schizophrenia or other serious brain disorders"(12). The American Psychological Association also actively lobbies against the death penalty on the basis that it is unfairly applied to the mentally ill (8). People who cannot categorize things, such as right and wrong, experience delusions and hallucinations that tell them to murder, or people that have difficulty inhibiting their emotions, abuse substances as a result of mental illnesses, and are paranoid cannot be held to the same standard of responsibility as the rest of population. On this basis, it is unjust to apply the death penalty to the mentally ill.

Works Cited

1) Barkataki, I., V. Kumari, M. Das, P. Taylor, and T. Sharma. "Volumetric Structural Brain Abnormalities in Men with Schizophrenia or Antisocial Personality Disorder." Brain Info. 6 Feb. 2006. Institute of Psychiatry, King's College London. 15 Feb. 2006 .

2)Christoff, Kalina. "Brain Structure and Function I." Brain and Behavior: Lecture 2. 31 Jan. 2005. Stanford University, Department of Psychology. 15 Feb. 2006

3)Claxton, Nathan S., Shannon H. Neaves, and Michael W. Davidson. "Rat Brain Tissue Sections: Lateral Ventricles." Olympus FloView Resource Center: Confocal Gallery. 2006. Florida State University. 15 Feb. 2006 .

4)Frederickson, Anne. "The Dopamine Hypothesis of Schizophrenia." Serendip. 1998. Bryn Maw College. 15 Feb. 2006 .

5)Hatfield, Agnes B. "Dual Diagnosis: Substance Abuse and Mental Illness." 1993. 15 Feb. 2006.

6) Mansnerus, Laura. "Damaged Brains and the Death Penalty." Death Penalty Info. 21 July 2001. Death Penalty Information Center. 15 Feb. 2006

7)"Mental Illness and the Death Penalty in the United States." American Civil Liberties Union). 31 Jan. 2005. 15 Feb. 2006.

8) "Resolution on the Death Penalty in the United States."American Psychological Association. APA. 2001.

9)"Schizophrenia Daily News Blog." Schizophrenia Daily News Blog: Crime and Schizophrenia. 27 Apr. 2005. 15 Feb. 2006

10) "Schizophrenia." National Institute of Mental Health,NIMH: Schizophrenia. 19 Oct. 2005. National Institute of Mental Health. 15 Feb. 2006 .

11)"The Amygdala: The Mind's "Emotional Engine" Focus of 2002 Conference Conference Set for March 24-26 in Galveston, Texas." The Amaygdala: The Mind's "Emotional Engine" 24 Mar. 2002. New York Academy of Sciences. 15 Feb. 2006

12) The Execution of Mentally Offenders: Summary Report." Amnesty International USA: The execution of mentally offenders- Summary Report. 2006. Amnesty International. 15 Feb. 2006

13) Thimble, Michael H. "Psychopathology of Frontal Lobe Syndromes." Psychopathology of Frontal Lobe Syndromes. Sept. 1990. 15 Feb. 2006

14) Torrey, E. Fuller. "Schizophrenia is a Disease of the Brain." is a Brain Disease. 15 Feb. 2006

| Course Home | Serendip Home |

Send us your comments at Serendip

© by Serendip 1994- - Last Modified: Thursday, 02-Mar-2006 14:45:10 EST