Evaluation (schizo); structural abnormalities

Question 1

Are the findings replicable?

Answer 1

• Robert McCarley and colleagues (1999) claim that the presence of enlarged ventricles in people with schizophrenia is the most reliable finding in research that uses brain scans. The link between cortical atrophy and cortical (e.g. Flashman and Green, 2004).
• However, structural abnormalities have not always been found and reproduced in studies of individuals with schizophrenia.
• McCarley et al. suggest such as the age, sex and severity of symptoms can all exert a powerful influence on the prevalence and pattern of the observed brain abnormalities’.
• This suggests that either structural abnormalities are only evident in some of those individuals diagnosed with schizophrenia or that we need to acknowledge more subtle differences, when assessing structural abnormalities.

Question 2

A cause or effect of schizophrenia

Answer 2

• As with the dopamine hypothesis, it is unclear whether structural abnormalities are the cause of schizophrenia or an effect of having schizophrenia.
• Although most researchers would probably argue that at least some structural abnormalities are a cause, we have to remember that environmental influences can significantly impact brain tissue.
• For example, Kenneth Lyon et al. (1981) reported that as doses of antipsychotic medications increased in their sample of participants, the density of brain tissue decreased. This suggests that perhaps after schizophrenia has been diagnosed and is treated with antipsychotic medications, the medication is what actually causes some structural abnormality such as enlarged ventricles.