Psychosis

Question 1

What is psychosis?

Answer 1

Presence hallucinations or delusions

Describes symptoms not a diagnosis itself

Question 2

What is a hallucination? Hallucinations in normal population?

Answer 2

Perception without a stimulus

Can be any sensory modality

Visual usually organic (problem brain/ eyes)

Hypnogogic - going to sleep

Hypnopompic - waking up

Question 3

What is a delusion?

Answer 3

Fixed false belief unshakeable

Outside cultural norms

Question 4

First rank symptoms of schizophrenia

Answer 4

Auditory hallucinations

Passivity experiences - action/ feeling caused by external force

Thought withdrawal (taken out of the mind)/ broadcast (everyone knows thoughts) / insertion (implanted by others)

Delusional perceptions - new meaning usually in sensory self-reference to a normally perceived object

Somatic hallucinations - mimics feelings form inside body e.g. heart twisting

Question 5

Examples of auditory hallucinations

Answer 5

Thought eco - hearing thoughts aloud

Running commentary

Third person - may converse about the pt

Question 6

Positive vs negative symptoms

Answer 6

Positive: delusions, hallucinations, thought disorder (jumps randomly), lack on insight
Added symptoms

Negative: underactivity, low motivation, social withdrawal, emotional flattening, self neglect
Take away from patient (sometimes left in this state after treating hallucinations e.g. sat doing nothing all day but not depression)

Question 7

Pathophysiology of schizophrenia

Answer 7

Dopamine pathways

Brain changes

Limbic system - regulating emotional behaviour

Basal ganglia - even untreated can present motor symptoms

Question 8

Dopamine theory of schizophrenia

Answer 8

Drugs e.g. amphetamines - cause release DA indices psychotic symptoms

All meds antagonise DA receptors, hell treat psychosis, strongest affinity most effective

4 DA pathways in Brain:

• mesolimbic, ventral tegmental area -> limbic structures + nucleus accumbens (overactive - positive symptoms)
• mesocortical pathway, ventral tegmental a -> frontal cortex + cingulate cortex (underatcive- negative symptoms)
• nigrostriatal, substantia nigra pars compacta -> striatum (caudate nucleus & putamen)
• tuberoinfundibular, arcuate + periventricular nuclei of hypothalamus -> infundibular region of hypothalamus

Question 9

Brain changes in schizophrenia

Answer 9

Enlarged ventricles

Reduced grey matter

Decreased temporal lobe volume

Reduced hippocampal formation, amygdala, parahippocampal gyrus & prefrontal cortex

Question 10

Neuropathology of schizophrenia

Answer 10

Decreased presynaptic markers

Decreased oligodenroglia

Fewer thalamic neurones

• aberrant connectivity

Question 11

Treatment of schizophrenia

Answer 11

• typical antipsychotics - block D2 receptors in all CNS dopaminergic pathways, main action on mesolimbic & mesocortical pathways - side effects from antagonising other pathways e.g. Parkinson’s symptoms

Atypical antipsychotics - loser affinity D2 receptors, milder side effects as dissociate rapidly, also block 5HT2 receptors - weight gain, hypercholesteroaemia, prolonged QT-> arrhythmias

• can be PO, short acting IM, long acting depot injections

Question 12

What is catatonic?

Answer 12

More than 2 weeks, one or more: 
Stupor/ mutism
Excitement
Posturing 
Negativism 
Rigidity 
Waxy flexibility- can be moulded
Command automatism 

Probs due less GABA binding so loss inhibitory effect

Avoided by early treatment

Question 13

Why do antipsychotics sometimes cause lactation?

Answer 13

Hyperprolactinemia - dopamine normally inhibits prolactin release from pituitary, Da anatagonists lower DA -> loss DA’s inhibitory function so increased prolactin levels

Can cause: amenorrhea, galactorrhoea, decreased fertility, reduced libido, long term -> osteopenia/ osteoporosis