Psychotic disorders

Question 1

Define psychosis

Answer 1

• A set of symptoms, not a diagnosis itself
• The presence of hallucinations or delusions

Question 2

What is a hallucination?

Answer 2

• A perception without an accompanying stimulus
• In any sensory modality
• Visual hallucinations are frequently caused by organic pathologies (e.g. tumour, eye disease)

Question 3

Give some examples of hallucinations that are not pathological

Answer 3

• Hypnogogic - experienced when going to sleep
• Hypnopompic - experienced upon waking

Question 4

What is a delusion?

Answer 4

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

Question 5

What are some misconceptions about schizophrenia?

Answer 5

• Not ‘split mind’
• Patients are no more dangerous than any other patient
• Only 5% of violent crimes are committed by those with severe mental illness

Question 6

What are the clinical features of schizophrenia?

Answer 6

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

Question 7

How can auditory hallucinations appear?

Answer 7

• Thought echo - hearing thoughts out loud
• Running commentary
• Third person - multiple voices talking about the patient

Question 8

What are passivity experiences?

Answer 8

• Belief that an action or feeling is caused by an external force

Question 9

What is thought withdrawal?

Answer 9

• Belief thoughts are being taken out of the mind

Question 10

What is thought broadcast?

Answer 10

• Belief that everyone knows what patient is thinking

Question 11

What is thought insertion?

Answer 11

• Belief that thoughts are being implanted by others

Question 12

What are delusional perceptions?

Answer 12

• Attribution of a new meaning to a normally perceived object

Question 13

What are somatic hallucinations?

Answer 13

• E.g. the sense of being touched when no one is there

Question 14

What are the positive symptoms of schizophrenia?

Answer 14

• Something added
• Delusions
• Hallucinations
• Thought disorder (problem with organisation of thoughts)
• Lack of insight

Question 15

What are the negative symptoms of schizophrenia?

Answer 15

• Something taken away
• Underactivity
• Low motivation
• Social withdrawal
• Emotional flattening
• Self neglect

Question 16

What is the dopamine theory describing the pathophysiology of schizophrenia?

Answer 16

• Drugs that increase dopamine levels (e.g. amphetamines) induce psychosis
• Drugs that antagonise dopamine treat psychosis (especially those that act at D2 receptors)

Question 17

What structural changes could lead to schizophrenia?

Answer 17

• Enlarged ventricles
• Decreased grey matter
• Decreased temporal lobe volume
• Reduced size of limbic structures and prefrontal cortex
• Changes at synapses
• Fewer oligodendrocytes
• Fewer thalamic neurones

Question 18

What is the possible role of the basal ganglia in schizophrenia?

Answer 18

• Some schizophrenics show movement disorder features

Question 19

How is schizophrenia treated?

Answer 19

• Typical antipsychotics
• Atypical antipsychotics

Question 20

What is the action of the typical antipsychotics used to treat schizophrenia?

Answer 20

• Block D2 receptors throughout the CNS
• Antipsychotic action from inhibition of mesolimbic and mesocortical pathways
• Side effects come from blocking other pathways

Question 21

What is the mechanism of action of the atypical antipsychotics?

Answer 21

• Lower affinity for D2 receptors than typicals so milder side effects
• Also block 5HT2 receptors (so some action on serotonin systems)

Question 22

What are the side effects of the atypical anipsychotics?

Answer 22

• Can affect movement due to involvement of nigrostriatal pathways (similar to Parkinson’s disease)
• However, untreated patients can also develop hypokinetic movement disorders (catatonia)
• Endocrine side effects

Question 23

What can cause hypokinetic movement disorders in schizophrenic patients?

Answer 23

• Might be caused by involvement of GABA

Question 24

What are the endocrine side effects of antipsychotics?

Answer 24

• Dopamine normally inhibits prolactin release
• Antipsychotics lead to increased prolactin levels
• Amenorrhoea
• Galactorrhoea
• Decreased fertility
• Decreased libido
• Osteoporosis

Question 25

What are the challenges in treating schizophrenia?

Answer 25

• Patients tend to lack insight, which can affect compliance with treatment
• To get around this, medication can be given in different ways such as a depot injection

Question 26

What is the prognosis of schizophrenia?

Answer 26

• If treatment is started early then good outlook
• About 50% will do well long term

Question 27

What are the factors associated with a good prognosis for schizophrenia?

Answer 27

• No family history
• Good premorbid function
• Acute onset
• Mood disturbance
• Prompt treatment
• Maintenance of motivation

Question 28

What are the long term complications of schizophrenia?

Answer 28

• All cause mortality twice as high as general population
• Shorter life expectancy
• Higher incidence of cardiovascular, respiratory disease and cancer
• 9x greater suicide risk than general population
• 2x greater risk of violent death than general population
• Substance misuse is common
• Many patients smoke