Theories of Causation of Schizophrenia

Theories of Causation of Schizophrenia

PowerPoint Summary

Carla Seeley

Psychology 101

John Mess

5/11/17

Introduction

Schizophrenia is a psychological disorder that disables the brain from functioning normally. Although the exact cause of schizophrenia is unknown, it is believed that various factors like genetic, psychological and environmental disposition make people more susceptible to developing this disorder. Also, stressful or emotional life events are thought to trigger this condition.  Schizophrenia distorts a person's thinking. Sufferers may have hallucinations (hearing or seeing things that are not there), delusions (beliefs that are not true), trouble organizing thoughts, and strange movements. The disorder typically appears during late adolescence or early adulthood. Men usually develop their first symptoms at an earlier age then women and African Americans are more often diagnosed with this condition. In this essay I will discuss the theories of causes of schizophrenia and how further research could improve treatment of this condition.

Genetic Causes

There are 108 known places in the genome which point towards genes that are involved in the causation of schizophrenia. No one gene is responsible for the genetic component of this illness, but rather a combination of genes.  Researchers have found that these genes are connected with the immune system. It is believed that if a person has a number of these gene variations and mutations, the risk of developing this mental illness increases. For example, when the gene COMT is abnormal, it depletes dopamine in the frontal lobes causing symptoms of schizophrenia such as having a false sense of reality and hallucinations. Research has suggested that it is more likely to be transmitted if a family member has it. Often, when a gene is associated with an illness, "typical" inheritance patterns mean that a person carrying that gene will be affected by this illness and this gene may be passed down to offspring. If a parent, brother or sister has been diagnosed with schizophrenia your chances of also developing this disorder go up by 10%. If both of your parents have it, you have a 40% chance of getting it too. Your chances are greatest at 50% if you have an identical twin with the disorder. Although it has been proven that heredity plays a big role in the cause of schizophrenia, it is not solely responsible.

Misuse of Drugs

People who abuse drugs sometimes develop symptoms that closely mimic schizophrenia. Continual drug abuse may actually trigger the onset of the condition. Nearly half of all schizophrenics in the US report abusing drugs. Schizophrenia may develop actively as a result of using hallucinogenic drugs in particular. Also marijuana use has been proven to be a factor in the start of the disease. THC, the psycho-active ingredient in marijuana, has a strong effect on the hippocampus and the prefrontal cortex making it difficult to form memories and make decisions. Similar brain structures in both drug addicts and schizophrenic patients have been seen. Over time the effects of drugs on the brain will increase the risk of the disorder developing going up even higher if the person already has a genetic predisposition to the disorder. Schizophrenic addicts especially, are more likely not to receive care and are less likely to be dual diagnosed and even if patients are receiving care, an underlying, unknown drug addiction while taking anti-psychotic medications will make the mental illness symptoms worse.

Trauma

        In a traumatic experience, our minds do not want to both remember the event and to forget it. Because our mind conflicts by blocking out the trauma but yet feeling that it is something that should not be forgotten either, the trauma can manifest itself in the form of hearing voices or having delusions (flashbacks), both schizophrenic symptoms. Similarities in brain structures have been found in both PTSD patients and schizophrenic patients. There is visible damage to the hippocampus, the adrenal pituitary axis is over-reactive and serotonin, dopamine and norepinephrine level abnormities can be seen in both kinds of patients. There is also a correlation between the severity of the trauma and the severity of psychotic symptoms.

Risk from Exposures in Infancy

It has been proven that exposure to toxins during the prenatal and perinatal periods play a big role in determining a person’s risk level of developing schizophrenia. In the prenatal period, exposure to influenza in the first trimester of pregnancy increases the risk level. Factors during the second and third trimester like maternal rubella and respiratory infections have also been linked to one’s level of risk of developing this condition. Maternal environmental factors during key developmental phases of the fetus like being from a low socioeconomic class and malnutrition can also leave one predisposed. Chemicals released due to maternal stress may have a negative impact on the developing brain of a fetus.