Session 12: Psychosis

Question 1

Definition of psychosis.

Answer 1

Presence of hallucinations or delusions

(It is not a diagnosis in itself)

Question 2

What are hallucinations?

Answer 2

Perception of a stimulus without there being a stimulus.

Can be in any sensory modality

Question 3

Give examples of normal hallucinations

Answer 3

Hypnogogic (hearing your name called when going to sleep e.g.)

Hypnopompic (hearing your name called when waking up e.g.)

Question 4

What are delusions?

Answer 4

Fixed false belief which is unshakeable and outside the cultural norm.

Question 5

First rank symptoms of schizophrenia

Answer 5

Auditory hallucinations

Passivity experiences

Thought withdrawal, broadcast or insertion

Delusional perceptions

Somatic hallucinations

Question 6

Give examples of types of auditory hallucinations in schizophrenia.

Answer 6

Thought echo (hearing thoughts aloud)

Running commentary

Third person voices

Question 7

What are passivity experiences?

Answer 7

Patient believes an action or feeling is caused by an external force.

E.g.

MI5 have been moving my leg

Question 8

What is thought withdrawal?

Answer 8

Thought are being taken out of the mind

Question 9

What is though broadcast?

Answer 9

Everyone knows what the person is thinking

Question 10

What is thought insertion?

Answer 10

Thoughts implanted by others

Question 11

What are delusional perceptions?

Answer 11

Attribution of new meaning usually in the sense of self-reference to a normally perceived object.

An example is:

Traffic lights went red and I knew this was a sign that aliens were going to land soon.

Question 12

Positive symptoms of schizophrenia

Answer 12

Delusions

Hallucinations

Thought disorder

Lack of insight

(These are added symptoms)

Question 13

Negative symptoms of schizophrenia.

Answer 13

Underactivity

Low motivation

Social withdrawal

Emotional flattening

Self neglect

(symptoms that are taken away from patient)

Question 14

Dopamine theory of schizophrenia.

Answer 14

Drugs like amphetamines which cause the release of dopamine agonists induces schizophrenic psychotic symptoms.

All medications that antagonise DA receptors help treat psychosis and those with the strongest affinity to D2 receptions are most clinically effective.

Question 15

2 main pathways involved in schizophrenia

Answer 15

Mesolimbic pathway

Mesocortical pathway

Question 16

Explain the mesolimbic pathway

Answer 16

From the ventral tegmental area to the limbic structures and the nucleus accumbens.

Question 17

What is different about the mesolimbic pathway in schizophrenia?

Answer 17

It is thought to be overactive

Question 18

Explain the mesocortical pathway.

Answer 18

From the ventral tegmental area and the goes to the frontal cortex and the cingulate cortex.

Question 19

What is different about the mesocortical pathway in schizophrenia?

Answer 19

It is thought to be underactive

Question 20

Brain changes in schizophrenia (macro).

Answer 20

Enlarged ventricles

Reduced grey matter

Decreased temporal lobe volume

Reduced hippocampal formation, amygdala, parahippocampal gyrus and prefrontal cortex.

Question 21

Neuropathology of schizophrenia

Answer 21

Decreased presynpatic markers

Decreased oligodendroglia

Fewer thalamic neurons

Question 22

Give other theories of schizophrenia.

Answer 22

Other limbic structure involvment - emotional behaviour

Basal ganglia involved since untreated patients can present with motor symptoms

Question 23

Treatment of schizophrenia.

Answer 23

Typical or atypical antipsychotics

Question 24

Action of typical antipsychotics.

Answer 24

Block D2 receptors in all CNS dopaminergic pathways.

The main action is on mesolimbic and mesocortical pathways.

Side effects arise from antagonising D2 receptors in other pathways.

Question 25

What is different about atypical antipsychotics?

Answer 25

Lower affinity for D2 receptors

MIdler side effects as they dissociate rapidly from D2 receptors

Also block 5HT2 receptors

Question 26

Explain nigrostriatal pathway.

Answer 26

From substantia nigra pars compacta to striatum (caudate nucleus and putamen)

Question 27

So if dopamine promotes movement, why do untreated patients develop catatonia?

Answer 27

Probably due to less GABA binding so loss of inhibitory effect

Question 28

Explain tuberoinfundibular pathway.

Answer 28

From arcuate and periventricular nuclei of hypothalamus and then to infundibular region of hypothalamus.

Question 29

Explain hyperprolactinaemia and antipsychotics.

Answer 29

Dopamine normally inhibits prolactin release from the pituitary.

DA antagonists lower DA leading to increased prolactin levels.

Question 30

Side effects of hyperprolactinaemia.

Answer 30

Amenorrhoea

Galactorrhoea

Decreased fertility

Reduced libido

Osteopenia/osteoporosis

Question 31

Why might it be difficult to treat patients with schizophrenia?

Answer 31

Lack of insight of patient

Medications are not often taken because they might think that the doctor is “one of them” who is trying to kill them etc…

Question 32

Prognosis of schizophrenia.

Answer 32

The earlier a diagnosis is made the better outcome.

There is a moderately good long term global outocme in about 50%

Question 33

Give examples of good prognostic factors.

Answer 33

Absence of FH

Good premorbid function

Acute onset

Mood disturbance

Prompt treatment

Maintenance of initiative and motivation

Question 34

What makes prognosis worse?

Answer 34

Mortality is twice as high as in gen pop

Short life expectancy

Higher incidence of CVS, resp and cancer.

Suicide risk 9x higher than gen pop

Substance misuse in around 50%

Higher rate of cigarette smoking