Ch.18- biopsychology of psychiatric disorders

Question 1

positive symptoms of schizophrenia

Answer 1

delusions, hallucinations, odd behaviour, inappropriate affect, disorganized speech

Question 2

negative symptoms of schizphrenia

Answer 2

affective flattening, avolition (loss of goal directed behaviours, motivation gone), catatonia (unable to move)

Question 3

duration of symptoms for a schizphrenia diagnosis

Answer 3

1 month , needs to have one of delusions, disorganized speech or hallucinations

Question 4

chlorpromazine

Answer 4

• first developped as an antihistamine
• alleviates symptoms of schizphrenia, calms ppl
  -emotionally blunted ppl are activated by it
• said to be a blocker, binds to dopamine without activating it

Question 5

reserpine

Answer 5

active ingrediant in snake root plant
- was good for schizophrenia but not used anymore bc casues blood pressure decline

Question 6

how did research on parkinsons help schizophrenia

Answer 6

• in parkinsons, striatum is depleted of dopamine
• this posits that the disruption to dopaminergic transmission produces both parkinsons disease and antipsychotic effects of the drugs chlorpromazine and reserpine

Question 7

dopamine theory of schizophrenia

Answer 7

• schizophrenia is caused by too much dopamine (antipsychotics chlorpromazine help treat this by decreasing dopamine levels)

Question 8

support for dopamine theory of schizophrenia

Answer 8

• in healthy ppl, excitatory drugs like amphetamiens can cause schizophrenia like symptoms bc they increase prescence of dopamine
• antipsychotic drugs (reserpine) break down synaptic vessicles which carry dopamine and thus reduce the levels of dopamine (chlorpromazine binds to dopamine receptors)

Question 9

work done by Carlsson and Lindquist on dopamine theory of schizophrenia

Answer 9

• found that lack of activity in post synaptic dopamine recopotrs triggered feedback loop wehre more dopamine was released explained why the exrtacellular levels of dopamine were the asme but metabolites were increased.
• chlorpromazine binds to the dopamine receptors but did not activate it, explaining why more was sent out and just kept getting metabolized
• rather than high levels of dopamine, schizophrenia is said to be caused by high levels of activity of dopamine receptors

Question 10

haloperidol (type of butyrophenone)

Answer 10

most potent antipsychotic drugs with low affinity for dopamine, odd bc most antipsychotics had a high affinity for dopamine

Question 11

explain why haloperidol is odd

Answer 11

odd bc it has high affinity for dopamine when the rest have low

• solution: dopamine binds to more than one dopamine receptor subtype
• chlorpromazine and others (phenothiazines_ bind to both D1 and D2 receptors
• haloperidol only binds to D2 (not D1)

Question 12

Typical antipsychotics and Snyder

Answer 12

• the degree to which first generation of antipsychotic drugs bind to D2 receptors is correlated with their effectiveness in suppressing symptoms of schizophrenia

Question 13

why is the butyrophenone spiroperdiol the most potent antipsychotic drug

Answer 13

it has a high affinity for D2 receptors

Question 14

limitation to dopamine theory

Answer 14

• doesnt explain why medicatio ntakes several weeks to work
• doesnt explain why antipsychotic medication are only effective for positive symptoms

Question 15

current version of dopamine theory