Antipsychotics

Question 1

what is psychosis?

Answer 1

severe disturbance in brain function in which normal perceptions of the environment are disrupted (dissociation from reality)

Question 2

what are “positive symptoms”?

Answer 2

hallucinations, paranoia, delusions, etc.

Question 3

what are “negative symptoms”?

Answer 3

apathy, social withdrawl, extreme inattentiveness

Question 4

what is the typical progression of schizophrenia?

Answer 4

continuous or relapsing episodes of psychosis (positive symptoms), usually followed later in the disease progression by the development of neative symptoms.

Question 5

what causes drug induced psychosis? Why? (2)

Answer 5

• cocaine/amphetamine use (increases dopamine neurotransmission)
• hallicinogens (impacts glutamate and serotonin transmission)

Question 6

What is the dopamine hypothesis relative to psychosis?

(4 main points)

Answer 6

• drugs that increase dopamine activity aggravate or produce psychosis
• schizophenia causes increased dopamine receptor density
• antipsychotics block D2 receptors
• treatment of schizophrenia reduces dopamine metabloites

Question 7

What are the 3 dopamine pathways?

Answer 7

1. nigrostriatal
2. mesocortical
3. mesolimbic

Question 8

the nigostriatal pathway is associate with what?

Answer 8

movement

Question 9

the mesocortical pathway is associate with what?

Answer 9

behaviour

Question 10

the mesolimbic pathway is associate with what?

Answer 10

behaviour

Question 11

antipsychotic drugs decrease psychotic symptoms by…

Answer 11

decreasing dopamine synaptic activity in the limbic pathway (binding to D2 receptors)

Note that the blocking of D2 in the cortex can cause negative symptoms!

Question 12

what are the 4 types of antipsychotics?

Answer 12

1. phenothiazine derivatives
2. thioxanthene derivatives
3. butyrophenone derivatives (haloperidol)
4. atypical (olanzapine)

Question 13

Haloperidol has high affinity for ____ and low affinity for ____.

Answer 13

D2 ; 5-HT2A

Question 14

Olanzapine has high affinity for ____ and low affinity for ____.

Answer 14

5-HT2A ; D2

Question 15

Olanzapine was comparable to haperidol in efficay in treating ____ symptoms, and was significantly superior in treating ____ symptoms.

Answer 15

positive ; negative

Question 16

Haloperidol and Olanzapine function by ____ their respective receptors.

Answer 16

blocking

Question 17

what is the current hypothesis cause the cause of negative symptoms in schizophrenia?

Answer 17

dopamine hypofunction in cortex.