12.2 Psychotic Disorders

Question 1

What’s the main psychotic disorder?

Answer 1

Schizophrenia

Question 2

What is psychosis?

Answer 2

Presence of hallucinations or delusions

Question 3

What are hallucinations?

Answer 3

Perception of stimuli without is being there. Can be in any sensory modality. Visual hallucinations are usually organic

Question 4

What is a hypnagogic hallucination?

Answer 4

A hallucination that occurs as you are going to sleep (usually auditory)

Question 5

What is a hypnopompic hallucination?

Answer 5

A hallucination experienced when waking up (normally auditory)

Question 6

What are delusions?

Answer 6

A fixed false belief, which is unshakeable. Outside of cultural norms.

Question 7

What are the first rank symptoms of schizophrenia?

Answer 7

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

Question 8

What are the different types of auditory hallucinations?

Answer 8

Second person hallucinations - voices are addressing you directly
Thought echo – hearing thoughts aloud
Running commentary – ‘He’s brushing his teeth, he’s sitting down’
Third Person - Voices referring to patient in third person and conversing with each other about the patient

Question 9

What are passivity experiences?

Answer 9

Patient believes an action or feeling is caused by an external force e.g. MI5 have been moving my leg
Not in control of own actions

Question 10

What is meant by thought withdrawal?

Answer 10

Thought withdrawal – thoughts are being taken out of the mind

Question 11

What is meant by though broadcast?

Answer 11

Everyone knows what the patient is thinking

Question 12

What is meant by though insertion?

Answer 12

Thoughts implanted by others

Question 13

What is delusion perception?

Answer 13

Delusional perception describes, confusingly, a true perception, to which a patient attributes a false meaning. For example, a perfectly normal event such as the traffic lights turning red may be interpreted by the patient as meaning that the martians are about to land.
New meaning cannot be understood as arising from patient’s affective state or previous attitudes

Question 14

What is somatic hallucinations?

Answer 14

A perception of being touched in the absence of a sensory stimulus is termed a somatic hallucination

Question 15

What are positive symptoms of schizophrenia ?

Answer 15

Symptoms that are gained:
Delusions
Hallucinations
Thought disorder
Lack of insight

Question 16

What are negative symptoms experienced by patients with schizophrenia?

Answer 16

Loss of feelings: under activity, low motivation, social withdrawal, emotional flattening, self neglect

Question 17

What are the 3 broad neurological changes seen in schizophrenia?

Answer 17

Dopamine pathway changes
Brain changes
Limbic system changes

Question 18

What is the dopamine theory of schizophrenia?

Answer 18

• Drugs e.g. amphetamines which cause the release of DA induces psychotic symptoms.
• All medications that antagonise DA receptors, help treat psychosis & those with the strongest affinity to D2 receptions are most clinically effective.
• 4 DA pathways in the brain.

Question 19

What are the 4 dopamine pathways in the brain?

Answer 19

Mesocortical pathway
Mesolimbic pathway
Nigrostriatal pathway
Tuberoinfundibular pathway

Question 20

Where does the mesolimbic pathway run?

Answer 20

From the Ventral tegmental area to the limbic structures and the nucleus accumbens

Question 21

Which dopamine pathway is overstimulated in schizophrenia?

Answer 21

Mesolimbic system - causes positive symptoms

Question 22

Where does the mesocortical pathway run?

Answer 22

From the ventral tegmental area to the frontal cortex and vinguate gyrus

Question 23

What causes the negative symptoms of schizophrenia?

Answer 23

The underactivity of the mesocortical pathway

Question 24

What are the structural brain changes of schizophrenia?

Answer 24

Enlarged ventricles
Reduced grey matter (with reduced brain weight)
Decreased temporal lobe volume (auditory hallucinations)
Reduced hippocampal formation, amygdala, parahippocampal gyrus and prefrontal cortex

Question 25

What is the neuropathology of schizophrenia?

Answer 25

• Decreased pre-synaptic markers
• Decreased oligodendroglia
• Fewer thalamic neurons
• Together these changes have led to a theory of “aberrant connectivity” causing schizophrenia.

Question 26

Other than the dopamine theory and the neuropatholocigal changes seen, what other structures are involved in schizophrenia?

Answer 26

Involvement of the limbic structures – as they have a role in regulating emotional behaviour
Basal ganglia – even untreated patients can present with motor symptoms

Question 27

What is the treatment of schizophrenia?

Answer 27

Typical antipsychotics (dopamine antagonists) = Block D2 receptors in all CNS dopaminergic pathways. Main action as antipsychotics is on mesolimbic and mesocortical pathways. But side effects come from antagonising D2 receptors in other pathways. Low dopamine levels associated with Parkinsonism

Atypical antipsychotics = Lower affinity for D2 receptors. Milder side effects as dissociate rapidly from D2 receptor. Also block 5HT2 receptors. Less Parkinsonism. Impaired glucose tolerance (diabetes), weight gain, hypercholesterolaemia, prolonged QT.

Question 28

Why do patients being treated for schizophrenia get parkinsonian symptoms?

Answer 28

As antipsychotics cause an overall decrease in dopamine in all pathways. A decrease in dopamine i the nigrostriatal pathway involves the basal ganglia and causes extra pyramidal side effects.
Ultimately leads to less glutamate released from the thalamus and overallleads to less movement

Question 29

Where does the nigrostriatal pathway run?

Answer 29

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

Question 30

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

Answer 30

Probably due to less GABA binding so loss of inhibitory effect

Question 31

What is Catalonia?

Answer 31

State of psychogenic motor immobility and behaioural abnormality manifested by stupor

Question 32

Where does the tuberoinfundibular pathway run?

Answer 32

From the arcuate and periventricular nuclei of hypothalamus to the infundibular region of hypothalamus

Question 33

What can decreased dopamine in the tuberoinfundibular pathway lead to?

Answer 33

amenorrhoea, galactorrhoea, decreased fertility,
reduced libido and long term can lead to osteopenia/osteoporosis
Due to decreased dopamine normally inhibits prolactin release from the pituitary. DA antagonists, which lower DA lead to loss of DA’s inhibitory function, and therefore increased prolactin levels.

Question 34

What are some of the difficulties in treating schizophrenia?

Answer 34

Lack of insight - patient doesn’t believe there is anything wrong with them
Medications not taken - poor adherence as dont believe medication is necessary and unwanted side effects such as drowsiness
Medications may need to be taken parentally as poor oral adherence.

Question 35

What are some factors that indicate a good prognosis with schizophrenia?

Answer 35

Absence of family history 
Good premorbid function 
Acute onset 
Mood disturbance 
Prompt treatment 
Maintenance of initiative and motivation

Question 36

What are some of the health risks / long term problems associated with schizophrenia?

Answer 36

Mortality is twice as high as in general
population
Shorter life expectancy
Higher incidence of CVS disease, respiratory disease and cancer
Suicide risk is 9x higher than in general population
Death from violent incidents in 2x as high
About 50% have a substance misuse problem
Higher rate of cigarette smoking