Bio-Dopamine hypothesis

Question 1

What is dopamine and where is it found?

Answer 1

A NT which is a chemical in the brain which influences our behaviour
Found in limbic system which includes the hypothalamus and the amygdala thought to be related by our emotional life
people with S have shown extreme emotional disturbance

Question 2

How does dopamine work?

Answer 2

Released and binds to the receptors which carries on the impulse
then NT goes back up and reabsorbed into the neuron

Question 3

What has reseach suggested about dopamine receptors?

Answer 3

increased number and abnormally high numbers of d2 receptors in the brain
shown though post mortems

Question 4

What are phenothiazines?

Answer 4

anti-phsychotic drug that had been found to reduce the symptoms of S reduces D activity by blocking D receptors
stops dopamine working by binding the receptor and carrying on the impulse

Question 5

What are the roles of amphetamines and LSD?

Answer 5

Drugs such as amphetamines and LSD are known to have effects on dopamine levels
drugs can induce states very similar to S in individuals
Randrup and Munkvad gave amphetamines to rats and observed similar behaviour to S

Question 6

What is L-DOPA?

Answer 6

can induce symptoms resembing paranoid S in parkinsons patients

Question 7

What has mesolimbic and mesocortical got to do with S?

Answer 7

Thought that high levels of D is the mesolimbic D system are the cause of positive symproms whereas high levels in mesocortical dopamine system are associated with negative symptoms

Question 8

Eval for dopamine?

Answer 8

Too simplistic x 2
Practical applications
Cause and effect
Other neurotransmitterd may be involved 
Drug companies may have inappropriately promoted D hypothesis

Question 9

Why is it too simplistic?

Answer 9

antipsychotics take weeks to worrk although they reduce D levels by blocking D2 receptors v quickly. You would expect that as soon as the D levels are reduced the symptoms should reduce immediately
may be that dopamine is the first step in the chain reaction of S symptoms and reducing levels leads to reduction in symptoms

ignores alternative expls

Question 10

What prac apps?

Answer 10

drug treatments, phenothiazines aim to reduce d levels

Question 11

Why is cause and effect an issue?

Answer 11

Cannot be sure that high D levels are the cause
you do not test S until it has developed eg pet scan
so how can you esablish cause and effect

Question 12

How may other NT’s be involved?

Answer 12

atypical antipsychotic is thought to have an influence on serotonin activity
and its suggested that atypical antips are more effective than typical that only influence D levels

Question 13

Why may drug companies cause problems?

Answer 13

Healy suggested that D hyp is promoted this is because if they can promote that D is the cause then people can buy drugs
peoples health is put at risk and influenced by a drug companies want to make a profit

Question 14

Researchers

Answer 14

Randrup and Munkvad
Iversen
Kessler
Wong

Question 15

What did Randrup and Munkvad do?

Answer 15

Gave amphetaimes to rats and observes behaviour similar to S

Question 16

What did Iverson do?

Answer 16

reported post mortems on people who has S

found excess D levels in limbic system suggesting involvement of the NT

Question 17

What did Kessler do?

Answer 17

used PET scans and MRI and found people with S had elevated D levels in basal forebrain

Question 18

What did Wong do?

Answer 18

found 2/3 increased in density of D receptor sites in the people with S who had never been treated