Biological Explanations of Schizophrenia

• Genetic Theory:

  :) RTS Tierney

  > studied 155 adopted children who had biological mothers with schizophrenia and found they had a concordance rate of 10% compared to 1% in adopted children without schizophrenic parents

  > provides support for the role of genetics as an explanation of schizophrenia - role of social learning theory could not have been a factor (children were adopted)
• Neural Correlates (brain structure):

  :) RTS Suddath

  > used MRI scans to investigate the brain structure of monozygotic twins, in which one twin was schizophrenic

  > schizophrenic twin generally had more enlarged ventricles

  > suggests enlarged ventricles play a role in determining the likelihood of developing schizophrenia
• :) scientific methods

  > theory is based on objective and empirical techniques, such as gene mapping and brain scans (e.g. fMRI), which are used to identify specific genes (PCM1) or areas of the brain linked to schizophrenia (enlarged ventricles)

  > increases overall internal validity of the biological explanation of schizophrenia, thus, raising Psychology's scientific status
• :( biological determinism

  > theory states that an individual is controlled by internal factors, such as high dopamine activity in the subcortex, which inevitably causes auditory hallucinations

  > neglects the role of free will and choice that individuals have - could leave victims feeling like they have no control over their schizophrenogenic behaviour

  > could be seen as unethical - victims' families feel guilty as they have passed a gene on that has affected their children

  > limits biological explanation
• :) practical applications

  > the principles of the theory, that schizophrenia is caused by an imbalance of dopamine, has led to the treatment of drug therapies such as typical and atypical antipsychotics

  > these drugs treat schizophrenia by balancing levels of dopamine in the brain so reducing symptoms such as hallucinations and delusions

  > biological explanation is an important part of applied psychology