Psychosis

Question 1

Define psychosis

Answer 1

• Presence of hallucinations or delusions

- Describe symptoms, not a diagnosis in itself

Question 2

Define hallucinations

Answer 2

• Perception without a stimulus
• Can be in any sensory modality
• Visual hallucinations are usually organic (caused by problem with brain or eyes)
• Hypnagogic hallucinations - going to sleep
• Hypnopompic hallucinations - waking up

Question 3

Define delusions

Answer 3

Abnormal belief, outside of culture norms

Question 4

Describe the first rank symptoms of psychosis

Answer 4

• Auditory hallucinations
  
  • Thought echo - hearing thoughts aloud
  • Running commentary - voices referring to patient in third person and conversing with each other about the patient
• Passivity experiences
  
  • Patient believes an action or feeling is caused by an external force
  • Eg. Someone has been moving my leg
• Through withdrawal, broadcast or insertion
  
  • Thought withdrawal - thoughts are being taken out of the mind
  • Thought broadcast - thoughts are being made known to others
  • Thought insertion - thoughts implanted by others
• Delusional perceptions
  
  • Attribution of new meaning, usually in the sense of self-reference, to a normally perceives object
  • Eg. The traffic lights went red and I knew this was a sign that aliens were going to land
• Somatic hallucinations
  
  • Mimics feeling from inside the body
  • Eg. It feels there is a snake inside me
• Lack of insight
  - Do not believe they are unwell

Question 5

Describe positive and negative symptoms of psychosis

Answer 5

• Positive symptoms - added symptoms
  
  • Delusions, hallucinations, thought disorder, lack of insight
• Negative symptoms - symptoms that take away from the patient
  - Underactivity, low motivation, social withdrawal, emotional flattening, self neglect

Question 6

List the types of schizophrenia

Answer 6

• Paranoid schizophrenia
• Simple schizophrenia
• Hebephrenic schizophrenia
• Undifferentiated schizophrenia
• Catatonic schizophrenia

Question 7

Describe paranoid schizophrenia

Answer 7

Delusions or hallucinations prominent

Question 8

Describe simple schizophrenia

Answer 8

• Loss of drive and interest, aimlessness, idleness, self absorbed attitude and social withdrawal
• Marked decline in social, academic or work performance
• No hallucinations/delusions

Question 9

Describe herbephrenic schizophrenia

Answer 9

• Aimless and disjointed behaviour or thought disorder affecting speech
• Hallucinations/delusions must not dominate

Question 10

Describe undifferentiated schizophrenia

Answer 10

• Insufficient symptoms to meet criteria of any subtypes or so many symptoms fit more than one criteria

Question 11

Describe catatonic schizophrenia

Answer 11

Voluntary movements stop and adopt unusual posture

Question 12

Describe the pathophysiology of schizophrenia

Answer 12

• Dopamine pathways altered in schizophrenia
• Mesolimbic pathway runs from ventral tegmental area to limbic structures and nucleus accumbens
  
  • Involved in motivation, reward, and positive symptoms of schizophrenia
  • Overactive in schizophrenia
• Mesocortical pathway runs from ventral tegmental area to frontal and cingulate cortex
  
  • Involved in cognition and emotion
    
    • Underactive in schizophrenia - loss of cognition and negative symptoms

Question 13

Describe the brain changes due to schizophrenia

Answer 13

• Enlarged ventricles

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

Question 14

Describe the treatment of schizophrenia

Answer 14

• Typical antipsychotics
  
  • Block D2 receptors in all CNS dopaminergic pathways
  • Main action as antipsychotics is on mesolimbic and mesocortical pathways
  • Many side effects - as all D2 receptors blocked
• Atypical antipsychotics
  
  • Low affinity for D2 receptors
  • Milder side effects as dissociated rapidly from D2 receptor
• Not that D2 receptors are located in the striatum, substantia nigra and pituitary gland
• Individual therapy - help patient normalise through patterns, cope with stress and identify early warning signs or relapse
• Avatar therapy - therapist uses avatar to communicate with patient

Question 15

Describe the effect of antipsychotics on the nigrostriatal pathway

Answer 15

• Nigrostriatal pathway runs from substantia nigra pars compacta to striatum (putamen) in the basal ganglia
• D2 antagonists reduce dopamine and thus cause a lack of movement as a side effect
• Can lead to stiffness, dystonia, bradykinesia, parkinsonism

Question 16

Describe the specific causes of psychosis mentioned in lecture

Answer 16

• Drug induced psychosis
• Affective psychosis - psychotic experiences are normally congruent with mood
  
  • Depressed patients may have delusions of guilt or nihilism (feel body is dead or rotting), unpleasant auditory hallucinations
• Post partum psychosis - very severe and needs to be recognized quickly to avoid harm to mother or baby