Pyschosis: Basic Sciences

Question 1

What is the main factor leading to schizophrenia?

Answer 1

GENES

78% heritability

Question 2

List other causes of schizophrenia

Answer 2

2nd trimester viral illness 
Obstetric problems
- pre eclampsia 
- fetal hypoxia
- emergency C- section
Substance Misuse
- amphetamines
- cocaine
- Cannabis

Question 3

Effect of drugs on schizophrenia and psychosis

Answer 3

May cause drug induced psychosis

If predisposed to schizophrenia, drug use may precipitate an episode and worsen prognosis

Question 4

Opiates cause psychosis - true or false?

Answer 4

FALSE

Question 5

Brain structure in schizophrenia with poor prognosis

Answer 5

1. reduced frontal lobe volume
2. Reduced frontal lobe grey matter
3. Enlarged lateral ventricles

Question 6

Grey matter abnormalities in Schizophrenia

Answer 6

1. widely distributed GM abnormalities
2. present early in illness
3. GM reductions due to reduced arborisation and not neuron loss
4. Grey matter reductions likely progressive in the initial years of illness

Question 7

White matter abnormalities in schizophrenia

Answer 7

Evidence from diffusion tensor Imaging:

1. reductions in white matter
2. mainly fronto temporal and around the ventricles
3. Assymetrical

Question 8

Can schizophrenia be diagnosed by neuro-imaging?

Answer 8

NO. Current neuroimaging methods have little relevance for clinical practice in psychiatry. New neuroimaging methods needed

Question 9

Dopamine hypothesis of schizophrenia

Answer 9

Dopamine excess causes psychosis

Question 10

Which is the main dopamine receptor involved in antipsychotics?

Answer 10

D2

Question 11

Other neurotransmitters in Schizophrenia

Answer 11

Glutamatergic hypothesis:
altered NMDA receptor subunit expression (ketamine can also induce psychotic symptoms)

Serotonergic hypothesis:
abnormalities in serotonin 2A binding potential in the frontal cortex index significantly smaller (by 16.3%) in patients with schizophrenia than in healthy subjects