1 - schizophrenia I

Question 1

how many people does schizophrenia effect?

Answer 1

1% of the population

Question 2

what are symptoms of schizophrenia?

Answer 2

• bizarre delusions
• inappropriate affect (emotional reactions)
• hallucinations
• incoherent thought
• odd behaviour
  positive symptoms (weren’t there before)

Question 3

what did Freud say about schizophrenia?

Answer 3

paranoid delusions result from repressed sexual urges which are striving for expression

Question 4

what is the difference between monozygotic and dizygotic twins?

Answer 4

monozygotic - identical twins , genes 100% same
dizygotic - fraternal twins - genes 50% same

Question 5

what is concordance rate?

Answer 5

degree of similarity between 2 things
e.g. the likelihood that schizophrenia is shared by two individuals

Question 6

what is the concordance rate for schizophrenia?

Answer 6

45% for identical twins
10% for fraternal twins
high rate of heritability

Question 7

what are factors other than genes?

Answer 7

• infections, autoimmune reactions, traumatic injury
• stress

Question 8

what was the first anti-psychotic drug that was discovered?

Answer 8

chlorpromazine
- originally marked as anti-histamine
- French surgeon noticed it calmed patients

Question 9

what was the second anti-psychotic drug discovered?

Answer 9

reserpine
- taken from snake root plant
- used to treat mental illness in India

Question 10

what are similarities between chlorpromazine and reserpine?

Answer 10

• take 2-3 weeks to work
• symptoms like those in Parkinson’s disease emerge
• then discovered that Parkinson’s was due to loss of dopamine in nitro-striatal pathway

Question 11

how does reserpine work?

Answer 11

depletes vesicles so reduces amount of DA that can be released

Question 12

how does chlorpromazine work?

Answer 12

blocks DA receptors so stops DA working

• false transmitter
• binds to DA receptors preventing DA from binding

Question 13

what is the dopamine theory?

Answer 13

drugs that reduce dopamine neurotransmission reduce psychotic symptoms

drugs that increase dopamine neurotransmission produce psychotic symptoms

Question 14

how do cocaine and amphetamine work?

Answer 14

block re-uptake transporter for dopamine (leaving more in synapse)

produce psychotic symptoms, not the same as psychosis

Question 15

what is the correlation between anti-psychotic drugs and binding with DA receptors?

Answer 15

positive correlation
the higher anti schizophrenic potency, the higher potency of binding to dopamine receptors

Question 16

what is the exception to the correlation between antiscizophrenic potency and binding to DA receptors?

Answer 16

haloperidol - high anti schizophrenic potency but didn’t bind to DA receptors

(binded to D2 not D1)

Question 17

what type of receptors are DA receptors?

Answer 17

metabotropic receptors (transmembrane proteins)

Question 18

how do D1 and D2 receptors differ?

Answer 18

D1 - positively coupled to adenylate cyclase
D2 - negatively coupled to adenylate cyclase

schizophrenia can be treated by blocking D2 receptors

Question 19

what are the families of DA receptors?

Answer 19

D1-like - D1, D5
D2-like - D2, D3, D4

Question 20

what does clozapine do?

Answer 20

blocks D4 receptors (atypical anti-psychotics)

Question 21

how does amount of DA receptors effect benefits of antipsychotic drugs?

Answer 21

people with more DA receptors responded better to antipsychotic drugs, they showed more improvement

Question 22

how can the amount of DA receptors in people with schizophrenia be measured?

Answer 22

deplete natural dopamine with a reserpine type drug so more DA receptors available

these can bind with drugs that make them radioactive so visible in PET scan

high number of receptors seen in schizophrenia after depletion of dopamine

suggests an overactive dopamine system in some people with schizophrenia