Psychosis and Schizophrenia

Question 1

what are the 3 core symptoms of psychosis?

Answer 1

1. Hallucinations- perceptions in the absence of stimulus
2. Delusions- a fixed and firm belief about something that is untrue or irrational
3. Disordered thinking- how one thought connects to another expressed by abnormalities of speech

Question 2

what are risk factors for psychosis?

Answer 2

family history
stress and trauma
drug use- cannabis and psychoactive substances
neonatal- low birth weight, birth trauma, infection
migration
urban living

Question 3

what is the stress vulnerability model for development of psychosis?

Answer 3

underlying risk factors convey vulnerability to psychosis. if you have greater vulnerability it takes a lower amount of stress to develop psychosis

Question 4

what are the limitations to classification systems for psychosis?

Answer 4

oversimplified
may contribute to over diagnosis
stigmatising

Question 5

how is dopamine synthesised?

Answer 5

tyrosine is converted to dihydroxyphenylamine (DOPA) and then to dopamine

Question 6

how is dopamine reabsorbed?

Answer 6

dopamine active transporter (DAT)

Question 7

how is dopamine broken down?

Answer 7

catechol-O-methyltransferase and monoamine oxidase

Question 8

what are the 3 main dopamine pathways in the brain?

Answer 8

1. mesolimibic
2. mesocortical
3. nigrostriatal

Question 9

which brain area is associated with dopamine?

Answer 9

ventral tegmental area

Question 10

which dopamine receptor is excitatory?

Answer 10

D1

Question 11

what changes occur in the mesolimibic pathway in schizophrenia?

Answer 11

hyperactivity of D2 receptors leading to positive symptoms of schizophrenia

Question 12

what changes occur in the mesocortical pathway in schizophrenia?

Answer 12

hypoactivity of D1 receptors leading to negative symptoms

Question 13

what are the positive and negative symptoms of schizophrenia?

Answer 13

positive- symptoms which aren’t normally there- hallucinations, delusions disordered thoughts
negative- absence of features that should be present- emotions, motivation, concentration

Question 14

how is noradrenaline synthesised?

Answer 14

tyrosine is converted to DOPA and then to dopamine which is converted to noradrenaline

Question 15

what receptors does noradrenaline act on and what effect does it have?

Answer 15

alpha and beta adrenergic receptors

it has an excitatory effect

Question 16

how is noradrenaline reabsorbed?

Answer 16

noradrenaline transporter (NET)

Question 17

how is noradrenaline broken down?

Answer 17

catechol-O-methyltransferase and monoamine oxidase

Question 18

which Brian area is associated with noradrenaline?

Answer 18

locus coeruleus

Question 19

how is serotonin synthesised?

Answer 19

tryptophan is converted to 5-hydroxy tryptophan which is converted to 5-hydroxy tryptamine

Question 20

how is serotonin reabsorbed?

Answer 20

5-hydroxy tryptamine transporter (5-HTT)

Question 21

how is serotonin broken down?

Answer 21

monoamine oxidase

Question 22

which brain area is associated with serotonin?

Answer 22

raphe nuclei

Question 23

how is acetylcholine synthesised?

Answer 23

binding of acetate and choline

Question 24

what are the 2 types of acetylcholine receptor?

Answer 24

nicotinic and muscarinic

Question 25

how is acetylcholine reabsorbed and recycled?

Answer 25

acetylcholinesterase breaks acteylcholine down into acetate and choline which is reabsorbed

Question 26

which brain areas is associated with acetylcholine?

Answer 26

basal forebrain and dorsolateral pons/tegmentum

Question 27

how is glutamate synthesised?

Answer 27

glutamate is converted to glutamine

Question 28

what are the glutamate receptors?

Answer 28

ionotropic AMPA, NMDA and kainate recpetors and metabotropic G protein coupled receptors

Question 29

which is the main excitatory neurotransmitter?

Answer 29

glutamate

Question 30

which is the main inhibitory neurotransmitter?

Answer 30

GABA

Question 31

how is GABA synthesised?

Answer 31

glutamate is converted to GABA

Question 32

what are the GABA receptors?

Answer 32

GABA A/ GABA C- inotropic | GABA B- metabotropic

Question 33

what changes occur in the temporal lobe in psychosis?

Answer 33

smaller hippocampus due to damage to GABAergic neurones leading to reduced inhibition and therefore increased activity

Question 34

how does NMDA receptor hypofunction impact dopamine pathways?

Answer 34

NMDA pathways may reduce mesocortical dopaminergic activity (negative symptoms) but remove GABA inhibition of VTA enhancing dopmamine release in mesolimbic areas (postivie symptoms)

Question 35

what is the mechanism of action of antipsychotics?

Answer 35

dopamine antagonists (blocks mesolimbic pathway to treat postive symptoms)

Question 36

what are the main side effects of typical antipsychotics?

Answer 36

extrapyramidal side effects- movement disorders e.g parkonsinism, dystonia, akasthesia

Question 37

what are the main side effects of atypical antipsychotics?

Answer 37

metabolic side effects- weight gain, diabetes

Question 38

what are the main groups of typical antipsychotics?

Answer 38

phenothiazines- chlopromazine, thioxanthenes- flupentixol bytyrophenes- haloperidol

Question 39

which drug is most effective for resistant schizophrenia?

Answer 39

clozapine- atypical antipsychotic

Question 40

what is prejudice?

Answer 40

a preconceived opinion that is not based on reason or actual experience