12. Psychosis

Question 1

What is the definition of psychosis?

Answer 1

Presence of hallucinations or delusions

Symptoms not a diagnosis itself

Question 2

What is a delusion?

Answer 2

A fixed false belief, which is unshakeable, outside of cultural norms

Question 3

What are the first rank symptoms of schizophrenia?

Answer 3

Auditory hallucinations
Passivity experiences
Thought withdrawal, broadcast or insertion
Delusional perceptions
Somatic hallucinations

Question 4

What are the Brian changes in schizophrenia?

Answer 4

Enlarged ventricles
Reduces grey matter
Decreased temporal lobe volume
Reduced hippocampal formation, amygdala, parahippocampal gyrus and prefrontal cortex

Question 5

What are the actions of the typical antipsychotics in treatment of schizophrenia?

Answer 5

Block D2 receptors in all CNS dopamine rigid pathways
Main action as antipsychotics is on mesolimbic and mesocortical pathways
But side effects come from antagonising D2 receptors in other pathway

Question 6

What are the actions of atypical antipsychotics in treatment of schizophrenia?

Answer 6

Lower affinity for D2 receptors
Milder side effects as dissociate rapidly from D2 receptors
Also block 5HT2 receptors