Neurotransmitter SZ Theory

Question 1

Neurotransmitter SZ Theory

Answer 1

Dopamine is thought to be the key neurotransmitter associated with psychosis.

Patients that abused a large amount of amphetamines showed positive symptoms.

Question 2

Dopamine - Randrup and Munkvad 1966

Answer 2

• Raised dopamine levels in rats brains by injecting amphetamines. They became stereotyped aggressive and isolated.

Question 3

Dopamine - What did Goldman Rakic et al suggest?

Answer 3

Abnormally low dopamine levels in prefrontal cortex may be responsible for negative symptoms of SZ.

Because prefrontal cortex is associated with logical thinking, so low levels could impair an individuals ability to construct grammatical

Question 4

What has the SZ dopamine hypothesis had important implications for?

Answer 4

Development of drug treatments for SZ (antipsychotics and dopamine antagonists).

Question 5

Dopamine - Lieberman et al 1987

Answer 5

75% of patients with SZ show new symptoms or increase in psychosis after taking amphetamines.

Question 6

Dopamine - D2 Receptors

Answer 6

Abnormally high dopamine levels in the frontal lobe, specifically Broca’s area which may have an excess of D2 receptors which may be responsible for the + symptoms of SZ auditory hallucinations due to overactivity of auditory areas of the brain.

Question 7

Neurotransmitter SZ Evaluation:

Answer 7

+ Typical antipsychotic drugs work by blocking dopamine receptors.

+ When Parkinson’s patients dose of DRA is too high, they experience SZ positive symptoms.

• Not all SZ respond to antipsychotic medicine blocking dopamine receptors.
• New atypical drugs (Clozapine) also block serotonin receptors.