SCIZOPHRENIA

Question 1

positive symptoms

Answer 1

hallucinations
delusions

Question 2

negative symptoms

Answer 2

blunted emotional responses
withdrawal from social interactions
lack of motivation
behave eccentrically
poverty of speech
poor attention spam

Question 3

cognitive symptoms

Answer 3

disorganised life > long term disability
no treatment
can be found to some degree before the positive symptoms appeared

Question 4

hallucinations

Answer 4

• precepts that occur in the absence of appropriate sensory stimuli
• auditory hallucinations

Question 5

delusions

Answer 5

firm beliefs that are not realistic and not explained by the patient’s culture

Question 6

periods of florid psychosis

Answer 6

accompanied by markedly disordered thinking and abnormalities in the regulation of emotion

interspersed with periods of residual symptoms

Question 7

treatement for schizophrenia

Answer 7

antipsychotics > most effective at diminishing positive symptoms

Question 8

aetiology of schizophrenia

Answer 8

genetically heterogeneous

may genes associated are expressed during neurodevelopment, therefore a neurodevelopmental disorder

Question 9

2 forms of genetic variation in schizophrenia

Answer 9

variations in single nucleotide bases

large chromosomal deletions, duplications, or translocations

22q11.2

Question 10

chromosomal translocation in sz

Answer 10

chromosomes 1 and 11

inactivates a gene (DISC-1)

Question 11

DISC-1

Answer 11

• important for brain development
• disrupted in schizophrenia-1
• DISC-1 must interact with other genes and non-genetic factors to determine the final phenotype

Question 12

amino acid neurotransmitters

Answer 12

glutamate
GABA

Question 13

biogenic amines neurotransmitters

Answer 13

histamine
serotonin
catecholamine (noradrenaline, adrenaline, dopamine)
acetylcholine

Question 14

neuropeptide neurotransmitters

Answer 14

orexin
oxytocin

Question 15

structural abnormalities

Answer 15

• thinning of specific areas of the prefrontal, temporal and parietal cerebral cortex
• prefrontal cortex > the most pronounced area > dorsolateral prefrontal cortex (working memory, cognitive function)
• temporal lobe > loss of grey matter in > the superior temporal gyrus, temporal pole, amygdala (may be limited to males), hippocampus

Question 16

cellular and synaptic level - grey matter

Answer 16

loss of grey matter in the cerebral cortex
- due to network dysfunction
- not the result of cell death
- a reduction in dendritic, axonal and synaptic processes

Question 17

cellular and synaptic level - smaller thalamus

Answer 17

• may be explained by cell death
• may be loss of cell bodies in the mediodorsal nucleus of the thalamus
• loss of axonal terminals in the DLPFC
• contribute to the reduction of cortical dendrites and the dendritic spines

Question 18

when are the abnormalities observed in sz

Answer 18

diagnosed in late teen years/early 20s

cortical abnormalities and ventricular enlargement are generally observed at the time of first diagnosis

Question 19

adolescent (healthy) brain

Answer 19

• early adulthood is an important period of brain development
• ‘synaptic pruning’ - circuit refinement
• may be particularly important in the PFC
• pruning coincides with major changes in dopaminergic neurotransmission during late adolescence

Question 20

1st generation antipsychotics in sz

Answer 20

• all act on dopaminergic pathways
• chlorpromazine (originally an anti-histamine)
• reducing positive symptoms such as hallucinations and delusions
• less impact on the negative symptoms and little/no impact on cognitive deficits
• produced Parkinson-like side effects

Question 21

2nd generation antipsychotics in sz

Answer 21

• clozapine has the best efficacy
• lower affinity for D2 receptors
• some also block the serotonin 5-HT 2A receptors

Question 22

clozapine in sz

Answer 22

• atypical drug
• affinity: D1, D2, 5HTRs, others

Question 23

chlorpromazine in sz

Answer 23

• ‘dirty’ drug
• acting on many receptors

Question 24

haloperidol in sz

Answer 24

• typical drug
• high affinity for D2 receptors

Question 25

olanzapine in sz

Answer 25

• atypical drug
• affinity for 5-HT 2A receptors > D2 receptors

Question 26

risperidone for sz

Answer 26

• qualitatively atypical drug
• more pronounced serotonin antagonism than dopamine antagonism

Question 27

D1 and D5 dopamine receptors

Answer 27

• coupled to stimulatory G proteins that activate adenylyl cyclase
• striatum, cerebral cortex and hippocampus

Question 28

D2, D3 and D4 dopamine receptors

Answer 28

• coupled to inhibitory G protein that inhibits adenylyl cyclase
• striatum, cerebral cortex, amygdala and hippocampus