Neural explanations

Question 1

Pharmacological evidence suggests that positive symptoms of schizophrenia …

Answer 1

… are caused by abnormalities in dopamine neurons (as in the receptor site)

Question 2

What does the dopamine hypotheses postulate?

Answer 2

Dopamine hypotheses postulate that hyperactivity (hyper-activity) of dopamine (high rates of firing) D2 receptor neurotransmission in the subcortical and limbic brain regions contributes to positive symptoms

Question 3

The efficacy of antipsychotics has been established in many double-blind studies by who?

Answer 3

(Baldessarini (1977)

Question 4

What has been said about the efficacy of antipsychotics?

Answer 4

The drugs actually eliminate, or at least diminish, the patient’s positive symptoms.

Question 5

What can negative symptoms of the disorder be attributed to

Answer 5

Hypofunctionality (under-activity) of dopamine (low firing rates) D1 receptor neurotransmission in the prefrontal cortex (Toda and Abi-Dargham, 2007)

Question 6

Outline Weinberger and Wyatt (1982) investigation

Answer 6

Weinberger and Wyatt (1982) obtained CT scans of 80 chronic schizophrenics and 66 non-schizophrenics of the same mean age (29)

Without knowledge of the patients’ diagnoses, they measured the area of the lateral ventricles in the scan that cut through them at their largest extent, and they expressed this area of brain tissue in the same scan.

The relative ventricle size of the schizophrenic patient was more than twice (due to the loss of brain tissue) as great as that of controls.

Question 7

AO3: Narrow focus on dopamine (-)

Answer 7

The traditional dopamine hypotheses can be critiqued for having a narrow focus on dopamine rather than other factors altering their levels. For example, Howes (2009) notes the importance of the theory to understand how dopamine can interact with genetic and environmental factors. A more multi-dimensional hypothesis would account for the complexity of disorders like schizophrenia such as considering factors like stress, trauma and drugs. The traditional hypotheses cannot explain this complex interplay of factors and overlook their role in the onset of schizophrenia. Perhaps an interactionist approach to explaining schizophrenia would be more plausible. Therefore, the traditional dopamine hypothesis may be deemed too simplistic when explaining schizophrenia.

Question 8

AO3: PPA antipsychotics Strange (2008)

Answer 8

Neural explanations of schizophrenia can be praised for having positive practical applications. For example, antipsychotic drugs were found to have one property in common- they block D2 dopamine receptors (Strange, 2008). This neural explanation allows for the development of specific medications that directly target the underlying neurochemical imbalances associated with the disorder. By blocking these receptors, antipsychotic drugs help to reduce the excessive dopamine activity in certain brain regions, leading to a decrease in positive symptoms like delusions and hallucinations. As such, schizophrenics prescribed antipsychotic medication can reintegrate into society and have a better quality of life. Therefore, neural explanations of schizophrenia can be given practical validity.