2. Brain abnormality as an explanation of mental illness

Question 1

Structural abnormalities - Van Erp et al (2015)
MRI scans compared to Non-Schizophrenic controls (3 differences)

Answer 1

MRI
Exposes the patient to strong magnetic fields which cause movement of electrons which can reveal detailed structures in the brain.

MRI scans compared to Non-Schizophrenic controls:

• Smaller nucleus accumbens (linked to positive symptoms of Sz and motivation) and larger pallidum (Part of reward circuit also important for motivation)
• Smaller amygdala (inability to affective cues when dealing with social interactions), hippocampus – part of limbic system, important for learning, memory (during psychosis it may hard for the patient to identify real and unreal memories).
• Larger ventricles – suggests loss of brain tissue and therefore less of functionality.

Question 2

Outline the explanation for Brain abnormality in mental illness [5] AO1 (model answer)

Answer 2

One explanation of the medical model of mental illness is brain abnormality. This suggests that mental illness is caused by a difference in brain structures. This can be applied to schizophrenia (SZ)

Research has suggested that people with SZ have abnormally large ventricles in the brain. Ventricles are fluid filled cavities, this means that the brains of SZ’s are lighter than normal which can affect functionality. This is supported by Swayze, he reviewed 50 studies of SZ and found that many had abnormally large amounts of liquid in the ventricles of the brain.

Van Erp furthered this by looking at specific parts of the brain. He found that SZ’s have smaller nucleus accumbens (linked to motivation) and pallidum’s, which are also part of the reward circuit for motivation. Smaller amygdala and hippocampus have been found which are linked to learning and memory e.g real and unreal memories formed during psychosis)

However other research by Bang-Choon Ho suggests that the larger ventricles are linked to anti-psychotic medicine, and it is this what has made the ventricles larger

Question 3

Brain Abnormality Evaluation - 3 Strengths

Answer 3

• Objective and scientific measures from using MRI machines.
• Useful as memory tasks can reverse shrinkage of hippocampus and reduce symptoms
• Could be considered holistic as it takes into account the roles of different areas of the brain.

Question 4

Brain Abnormality Evaluation - 3 Weaknesses

Answer 4

• Lacks validity as changes in brain structure could be caused by the
  antipsychotic drugs not the disorder.
• Could be considered reductionist as it only focuses on how brain structure affects sz.
• Not useful as it doesn’t help to develop any sort of treatment from this knowledge