Furii’s Flaming Finger’sFurii’s Flaming Finger’s(A.K.A.: Team 1)(A.K.A.: Team 1)

Possible Causes of Possible Causes of SchizophreniaSchizophrenia

By: Andrew, Anne, Connie and Diana

Genetics - InterplayGenetics - Interplay

Experts now agree that schizophrenia develops as a result Experts now agree that schizophrenia develops as a result of interplay between biological predisposition (for example, of interplay between biological predisposition (for example, inheriting certain genes) and the kind of environment a inheriting certain genes) and the kind of environment a person is exposed to (schizophrenia.com).person is exposed to (schizophrenia.com).

Schizophrenia researchers break down the causes of Schizophrenia researchers break down the causes of schizophrenia into two categories:schizophrenia into two categories: Genetic(s) (schizophrenia.com)Genetic(s) (schizophrenia.com) Environment (everything other than genes) Environment (everything other than genes)

(schizophrenia.com).:(schizophrenia.com).: ““Social, nutritional, hormonal and chemical environment in the Social, nutritional, hormonal and chemical environment in the

womb of the mother during pregnancy, up to the social dynamics womb of the mother during pregnancy, up to the social dynamics and stress a person experiences, to street drug use, education, and stress a person experiences, to street drug use, education, virus exposure, vitamin use, and much, much more” virus exposure, vitamin use, and much, much more” (schizophrenia.com).(schizophrenia.com).

Another way to think of this is “Nature vs. Nuture” or Another way to think of this is “Nature vs. Nuture” or “genes vs. environment” (schizophrenia.com).“genes vs. environment” (schizophrenia.com).

Genetics - ExamplesGenetics - Examples

An example of how a genetic predisposition for An example of how a genetic predisposition for schizophrenia can be triggered by environmental schizophrenia can be triggered by environmental influences can be seen in a research study taken influences can be seen in a research study taken from Biological Psychiatry, Volume 57:from Biological Psychiatry, Volume 57: Indicates that people who had multiple copies of a version Indicates that people who had multiple copies of a version

of the COMT gene and who smoked marijuana had a of the COMT gene and who smoked marijuana had a 1,000% increase in their risk of developing schizophrenia 1,000% increase in their risk of developing schizophrenia (as cited on schizophrenia.com).(as cited on schizophrenia.com).

Another example from the British Journal of Another example from the British Journal of Psychiatry:Psychiatry: Indicates that adopted children with high Indicates that adopted children with high

genetic/biological risk for schizophrenia (their mother had genetic/biological risk for schizophrenia (their mother had schizophrenia) had an 86% lower rate of developing schizophrenia) had an 86% lower rate of developing schizophrenia raised in a healthy vs. a dysfunctional schizophrenia raised in a healthy vs. a dysfunctional family. Only 6% of the children developed schizophrenia in family. Only 6% of the children developed schizophrenia in the healthy family. 37% of the children of the the healthy family. 37% of the children of the dysfunctional families developed schizophrenia (as cited dysfunctional families developed schizophrenia (as cited on schizophrenia.com).on schizophrenia.com).

Genetics - ResearchGenetics - Research

There are multiple genes being researched right now that may be There are multiple genes being researched right now that may be contributing to the schizophrenia. There are about a dozen that contributing to the schizophrenia. There are about a dozen that are the leading contributors (schizophrenia.com).are the leading contributors (schizophrenia.com).

There is also research being done to investigate what biological There is also research being done to investigate what biological molecules may be responsible for turning on and off certain genes molecules may be responsible for turning on and off certain genes contributing to schizophrenia (schizophrenia.com).contributing to schizophrenia (schizophrenia.com).

The predominance of these and other factors probably varies from The predominance of these and other factors probably varies from person to person in schizophrenia (Encyclopedia Britannica, 2008).person to person in schizophrenia (Encyclopedia Britannica, 2008).

It is becoming more evident that having a gene or genes linked to It is becoming more evident that having a gene or genes linked to schizophrenia is just the start. If you aren’t exposed to the schizophrenia is just the start. If you aren’t exposed to the environmental factors that contribute to schizophrenia, then it is environmental factors that contribute to schizophrenia, then it is likely you will never get it (schizophrenia.com).likely you will never get it (schizophrenia.com).

Having a predisposition and being exposed to certain Having a predisposition and being exposed to certain environmental factors certainly increases the chances of environmental factors certainly increases the chances of developing schizophrenia. The more environmental factors you developing schizophrenia. The more environmental factors you are exposed to, the higher the risk (schizophrenia.com).are exposed to, the higher the risk (schizophrenia.com).

Genetics - ChartGenetics - Chart Experts now promote that schizophrenia along with all other mental illness is Experts now promote that schizophrenia along with all other mental illness is

caused by a combination of biological, psychological and social factors, this caused by a combination of biological, psychological and social factors, this understanding is called the bio-psycho-social model.understanding is called the bio-psycho-social model.

The following charts show the probable factors and path leading to the onset The following charts show the probable factors and path leading to the onset of schizophrenia:of schizophrenia:

Chart taken from a presentation by Dr. Ira Glick, “New Schizophrenia Treatments” (as shown on schizophrenia.com).

Genetics - ChartGenetics - Chart

Chart taken from a presentation by Dr. Ira Glick, “New Schizophrenia Treatments”

(as shown on schizophrenia.com).

Genetics – Family StudiesGenetics – Family Studies

Family risk studies:Family risk studies: Compares the observed frequency of the mental illness in close Compares the observed frequency of the mental illness in close

relatives of a patient vs. the frequency in the general population relatives of a patient vs. the frequency in the general population (Encyclopedia Britannica, 2008).(Encyclopedia Britannica, 2008).

““First-degree relatives (parents, siblings, and children) share 50 First-degree relatives (parents, siblings, and children) share 50 percent of their genetic material with the patient, and higher rates of percent of their genetic material with the patient, and higher rates of the illness in these relatives than expected indicate a possible genetic the illness in these relatives than expected indicate a possible genetic factor” (Encyclopedia Britannica, 2008).factor” (Encyclopedia Britannica, 2008).

Further information on the impact of genetics versus environmental Further information on the impact of genetics versus environmental factors can be taken from comparing identical twins reared together factors can be taken from comparing identical twins reared together with those reared apart (Encyclopedia Britannica, 2008).with those reared apart (Encyclopedia Britannica, 2008).

Adoption studies comparing children whose biological parents who had Adoption studies comparing children whose biological parents who had schizophrenia with those whose parents did not can also be useful in schizophrenia with those whose parents did not can also be useful in separating biological from environmental influences (Encyclopedia separating biological from environmental influences (Encyclopedia Britannica, 2008).Britannica, 2008).

““These studies have demonstrated a clear role for genetic factors in These studies have demonstrated a clear role for genetic factors in the causation of schizophrenia” (Encyclopedia Britannica, 2008).the causation of schizophrenia” (Encyclopedia Britannica, 2008).

Genetics – Risk ChartGenetics – Risk Chart

The Dopamine The Dopamine HypothesisHypothesis

States that the excess of dopamine States that the excess of dopamine activity in the mesocortical dopamine activity in the mesocortical dopamine system produces the positive system produces the positive symptoms of Schizophrenia.symptoms of Schizophrenia.

This was discovered by accident in This was discovered by accident in 1950 by Henri Laborit when he 1950 by Henri Laborit when he noticed that antihistamine drugs noticed that antihistamine drugs prescribed to his patients reduced prescribed to his patients reduced anxieties without producing mental anxieties without producing mental confusion.confusion.

                    

The Dopamine The Dopamine HypothesisHypothesis

Chemist Paul Charpentier developed Chemist Paul Charpentier developed chlorpromazine (antihistamine) and chlorpromazine (antihistamine) and tested it on animals which was later tested it on animals which was later tested on humans.tested on humans.

It proved to be an effective treatment It proved to be an effective treatment only for patients with schizophrenia only for patients with schizophrenia by alleviating or eliminating their by alleviating or eliminating their hallucinations and delusions.hallucinations and delusions.

How does this work you How does this work you ask…ask…

Chlorpromine acts as a Chlorpromine acts as a dopamine antagonist by dopamine antagonist by blocking postsynapic blocking postsynapic dopaminergic receptors dopaminergic receptors thus supporting the thus supporting the dopamine hypothesis.dopamine hypothesis.

Other experiments show Other experiments show that chlorpromine and that chlorpromine and other antipsychotic other antipsychotic drugs selectively bind to drugs selectively bind to dopamine receptor sites.dopamine receptor sites.

The Dopamine The Dopamine HypothesisHypothesis People with schizophrenia have People with schizophrenia have

occasionally been found to have occasionally been found to have abnormally high levels of dopamine abnormally high levels of dopamine metabolites in their blood plasma.metabolites in their blood plasma.

In addition, drugs such as In addition, drugs such as amphetamines and cocaine that amphetamines and cocaine that increase dopamine activity in the CNS increase dopamine activity in the CNS can often produce positive can often produce positive symptoms of schizophrenia in symptoms of schizophrenia in individuals without this individuals without this disorder. disorder.

The Hypofrontality The Hypofrontality TheoryTheory

States that the negative symptoms of States that the negative symptoms of schizophrenia are caused by decreased schizophrenia are caused by decreased activity in the prefrontal cortex.activity in the prefrontal cortex.

In PET scans, it has shown that people In PET scans, it has shown that people with schizophrenia show decreased with schizophrenia show decreased metabolic activity in the frontal region metabolic activity in the frontal region of the brain.of the brain.

Support for this Support for this HypothesisHypothesis

Damage to the prefrontal cortex Damage to the prefrontal cortex in people who do not have in people who do not have schizophrenia often have schizophrenia often have motivational difficulties, motivational difficulties, confusion, decreased speech, confusion, decreased speech, flat affect, and social withdrawal.flat affect, and social withdrawal.

Also researchers have concluded that the Also researchers have concluded that the negative symptoms of schizophrenia negative symptoms of schizophrenia reflect prefrontal cortex deficits.reflect prefrontal cortex deficits.

Problems with this Problems with this TheoryTheory

Not all persons with Not all persons with schizophrenia exhibit schizophrenia exhibit hypofrontalityhypofrontality

Recently in a meta-Recently in a meta-analysis involving more analysis involving more than 4000 people with than 4000 people with schizophrenia, schizophrenia, hypofrontality was hypofrontality was exhibited in exhibited in approximately half of the approximately half of the patients (Davidson & patients (Davidson & Heinrichs, 2003)Heinrichs, 2003)

Abnormal Brain StructureAbnormal Brain Structure

Enlarged ventriclesEnlarged ventricles Smaller temporal and frontal lobesSmaller temporal and frontal lobes Smaller amounts of gray matterSmaller amounts of gray matter Abnormal blood flowAbnormal blood flow Abnormal amounts of neurotrophinsAbnormal amounts of neurotrophins Disorganized hippocampal cellsDisorganized hippocampal cells

Viral Infections and Viral Infections and SchizophreniaSchizophrenia

Fetal exposure to viral infections such as Fetal exposure to viral infections such as influenza influenza Many individuals with schizophrenia are born in Many individuals with schizophrenia are born in

winter months winter months Toxoplasma gondiiToxoplasma gondii

Intracellular parasite found in cat feces or uncooked Intracellular parasite found in cat feces or uncooked meatmeat

Known to cause abortions and stillbirthsKnown to cause abortions and stillbirths Can also cross the placenta and cause changes in Can also cross the placenta and cause changes in

head size,deafness, cerebral palsy, mental head size,deafness, cerebral palsy, mental retardation and later in life- psychosis such as retardation and later in life- psychosis such as delusions and hallucinations delusions and hallucinations

Sociocultural ViewsSociocultural Views

According to Comer (2007), sociocultural theorists believe According to Comer (2007), sociocultural theorists believe that people with mental disorders are victims of social forces. that people with mental disorders are victims of social forces. They say that both They say that both social labelingsocial labeling and and family dysfunctionfamily dysfunction contribute to the development of schizophrenia.contribute to the development of schizophrenia.Social Labeling: certain features of this disorder are Social Labeling: certain features of this disorder are influenced by the diagnosis itself (Modrow,1992 as cited in influenced by the diagnosis itself (Modrow,1992 as cited in Comer, 2008). The label of schizophrenic is given to those Comer, 2008). The label of schizophrenic is given to those persons in society that do not conform to certain norms or persons in society that do not conform to certain norms or behaviors. behaviors. Regardless of whether the label is justified or not, it does Regardless of whether the label is justified or not, it does become a self fulfilling prophecy, which then promotes the become a self fulfilling prophecy, which then promotes the development of several schizophrenic symptoms.development of several schizophrenic symptoms.Being labeled “crazy” might encourage people to display Being labeled “crazy” might encourage people to display psychotic behaviors (they accept and play the role). Dangers psychotic behaviors (they accept and play the role). Dangers of diagnostic labeling (Rosenhan, 1973).of diagnostic labeling (Rosenhan, 1973).

Family DysfunctionFamily Dysfunction

Theorists have said for years that certain patterns of family Theorists have said for years that certain patterns of family interaction can promote or sustain schizophrenic symptoms.interaction can promote or sustain schizophrenic symptoms.

Schizophrenia has often been linked to family stress (Boye Schizophrenia has often been linked to family stress (Boye et al., 2002; Schiffman et al., 2002, 2001; Miklowitz et al., et al., 2002; Schiffman et al., 2002, 2001; Miklowitz et al., 1995 as cited in Comer, 2007). Parents with people who 1995 as cited in Comer, 2007). Parents with people who have schizophrenia more times than not 1) display more have schizophrenia more times than not 1) display more conflict, 2) have greater difficulty communicating with one conflict, 2) have greater difficulty communicating with one another, 3) are more critical of and over-involved with their another, 3) are more critical of and over-involved with their children than other parents. Family theorists have observed children than other parents. Family theorists have observed that some families are high in that some families are high in express emotionexpress emotion. This means . This means that the family members criticize, disapprove of, are hostile that the family members criticize, disapprove of, are hostile towards each other as well as intrude on one another’s towards each other as well as intrude on one another’s privacy very frequentlyprivacy very frequently. .

People who have this disorder and live with such families People who have this disorder and live with such families are four times more likely to relapse, while trying to recover are four times more likely to relapse, while trying to recover (Comer, 2007).(Comer, 2007).

Double Bind HypothesisDouble Bind Hypothesis

This is a theory that says that some parents communicate This is a theory that says that some parents communicate mutually contradictory messages to their children which places mutually contradictory messages to their children which places them in a double bind situation. This causes the children to them in a double bind situation. This causes the children to constantly displease their parents “never doing anything right”.constantly displease their parents “never doing anything right”.

Double-bind messages are primarily verbal and non-verbal Double-bind messages are primarily verbal and non-verbal (contradictory metacommunication) (Comer, 2007).(contradictory metacommunication) (Comer, 2007).

Children repeatedly exposed to this kind of communication will Children repeatedly exposed to this kind of communication will develop strategies to cope. Some children will ignore the develop strategies to cope. Some children will ignore the primary communication and respond to the non-verbal primary communication and respond to the non-verbal communication, they become suspicious of what is being said communication, they become suspicious of what is being said to them (always trying to figure out the meaning behind what to them (always trying to figure out the meaning behind what is said), focus on clues in gestures, tones. When one is said), focus on clues in gestures, tones. When one increasingly responds to messages in this way, then they may increasingly responds to messages in this way, then they may move towards becoming a paranoid schizophrenic (Comer, move towards becoming a paranoid schizophrenic (Comer, 2007). 2007).

Sociocultural-Existential ViewSociocultural-Existential View

This is a theory that was developed by a clinical theorist This is a theory that was developed by a clinical theorist named R.D. Laing.named R.D. Laing.

This theory combined sociocultural views with existential This theory combined sociocultural views with existential ones. It argues that schizophrenia is a constructive ones. It argues that schizophrenia is a constructive process where people try to cure themselves of the process where people try to cure themselves of the unhappiness and confusion caused by their social unhappiness and confusion caused by their social environment. Liang said that if these people were left environment. Liang said that if these people were left alone then they would get better. alone then they would get better.

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March 12, March 12, 2008, from www.schizophrenia.com: 2008, from www.schizophrenia.com: http://www.schizophrenia.com/hypo.phphttp://www.schizophrenia.com/hypo.php

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psychology. New York: Worth Publishers. Klein, S. B. & Thorne, B. M. (2007). Klein, S. B. & Thorne, B. M. (2007). Biological psychology. Biological psychology. New New

York, NY: York, NY: Worth PublishersWorth Publishers Torrey, E. F., Yolken, R. H. (2003). Toxoplasma gondii and Torrey, E. F., Yolken, R. H. (2003). Toxoplasma gondii and

schiophrenia. schiophrenia. Emerging Infectious Diseases, 9, 1375-1380.Emerging Infectious Diseases, 9, 1375-1380.