Explanations of Schizophrenia

Genetic 

Belief that there is link between schizophrenia and inherited genetic material. Thus, the closer one’ genetic is to someone diagnosed with the mental illness, the more likely they are to be diagnosed themselves. 

GOTTESMAN AND SHIELDS (1972) found that the closer the genetic relationships between two people, the higher the chance that if one of them is diagnosed with schizophrenia, the higher the chance that the other will too.However, the concordance rates were not 100%, which leads researchers to assume that the environment plays a part in triggering the disorder.

For more detailed information – Gottesman and Shields (1972)

Biochemical – Dopamine hypothesis 

Dopamine is a neurotransmitter, which was found to be chemically similar to hallucinogenic drugs that produce effects similar to schizophrenia. 

• Therefore the belief that schizophrenics brains are more sensitive to dopamine was created. Apparently, the disorder is caused by an excess of the chemical in the brain.
• Further research that makes the hypothesis reliable is that drug treatment to reduce dopamine levels leads to symptoms similar to those of Parkinson’s disease, which is caused by low levels of the same chemical.

Linstoem et al (1999) used PET scans to test the hypothesis by injecting a radioactively labelled chemical called L-DOPA, which is related to the production dopamine. It was found that this was taken up quicker in the schizophrenic brain since there is more of the neurotransmitter.

Cognitive 

Idea that schizophrenia is a result of defective processing mechanism, a selective attention of deficiency, a lack of brain filter and an inability to interpret external stimuli.

FRITH (1992) studied faulty cognitive processes and the schizophrenic theory of mind – the belief that people diagnosed with the disorder cannot distinguish internal and external actions. E.g. hearing voices is not recognized as being self-generated. 

• He noted that schizophrenics may have a deficient META-REPRESENTATION,which is the mechanism that allows us to have a theory of mind. 
• This is believed to be caused by a disconnection between frontal areas of the brain – actions – and rear areas – perceptions.