Dopamine Hypothesis

Question 1

What is the dopamine hypothesis

Answer 1

Symptoms of schizophrenia are due to an excess of dopamine

Question 2

What are 3 factors that led to the dopamine hypothesis

Answer 2

1. Anti-psychotic drugs
2. Amphetamine psychosis
3. Post mortem studies

Question 3

How did anti-psychotic drugs lead to the dopamine hypothesis

Answer 3

Anti-psychotic drugs blocked dopamine receptors and alleviated positive symptoms

Parkinson’s - low levels of dopamine. When given l-dopa they had psychotic symptoms

Question 4

How did amphetamine psychosis lead to the dopamine hypothesis

Answer 4

Amphetamines increase dopamine activity

Those taking high levels of amphetamines for long periods of time produced behaviours similar to symptoms of psychosis

Question 5

How did post mortem studies lead to the dopamine hypothesis

Answer 5

Increased levels of dopamine and more dopamine receptors in brains of those with schizophrenia

Question 6

What 2 pathways are involved in the production of psychotic symptoms

Answer 6

Mesolimbic pathway

Mesocortical pathway

Question 7

What are 3 weaknesses of the dopamine hypothesis

Answer 7

1. Antipsychotic drugs do not begin working until after 6 weeks of taking
2. New antipsychotics reduce positive symptoms but have a small effect on dopamine levels.
3. Other neurotransmitters are involved in creating psychotic symptoms e.g serotonin, GABA