12.2 Psychotic Disorders Flashcards
What’s the main psychotic disorder?
Schizophrenia
What is psychosis?
Presence of hallucinations or delusions
What are hallucinations?
Perception of stimuli without is being there. Can be in any sensory modality. Visual hallucinations are usually organic
What is a hypnagogic hallucination?
A hallucination that occurs as you are going to sleep (usually auditory)
What is a hypnopompic hallucination?
A hallucination experienced when waking up (normally auditory)
What are delusions?
A fixed false belief, which is unshakeable. Outside of cultural norms.
What are the first rank symptoms of schizophrenia?
- Auditory hallucinations
- Passivity experiences
- Thought withdrawal, broadcast or insertion
- Delusional perceptions
- Somatic hallucinations
What are the different types of auditory hallucinations?
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
What are passivity experiences?
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
What is meant by thought withdrawal?
Thought withdrawal – thoughts are being taken out of the mind
What is meant by though broadcast?
Everyone knows what the patient is thinking
What is meant by though insertion?
Thoughts implanted by others
What is delusion perception?
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
What is somatic hallucinations?
A perception of being touched in the absence of a sensory stimulus is termed a somatic hallucination
What are positive symptoms of schizophrenia ?
Symptoms that are gained: Delusions Hallucinations Thought disorder Lack of insight
What are negative symptoms experienced by patients with schizophrenia?
Loss of feelings: under activity, low motivation, social withdrawal, emotional flattening, self neglect
What are the 3 broad neurological changes seen in schizophrenia?
Dopamine pathway changes
Brain changes
Limbic system changes
What is the dopamine theory of schizophrenia?
- 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.
What are the 4 dopamine pathways in the brain?
Mesocortical pathway
Mesolimbic pathway
Nigrostriatal pathway
Tuberoinfundibular pathway
Where does the mesolimbic pathway run?
From the Ventral tegmental area to the limbic structures and the nucleus accumbens
Which dopamine pathway is overstimulated in schizophrenia?
Mesolimbic system - causes positive symptoms
Where does the mesocortical pathway run?
From the ventral tegmental area to the frontal cortex and vinguate gyrus
What causes the negative symptoms of schizophrenia?
The underactivity of the mesocortical pathway
What are the structural brain changes of schizophrenia?
Enlarged ventricles
Reduced grey matter (with reduced brain weight)
Decreased temporal lobe volume (auditory hallucinations)
Reduced hippocampal formation, amygdala, parahippocampal gyrus and prefrontal cortex
What is the neuropathology of schizophrenia?
- Decreased pre-synaptic markers
- Decreased oligodendroglia
- Fewer thalamic neurons
- Together these changes have led to a theory of “aberrant connectivity” causing schizophrenia.
Other than the dopamine theory and the neuropatholocigal changes seen, what other structures are involved in schizophrenia?
Involvement of the limbic structures – as they have a role in regulating emotional behaviour
Basal ganglia – even untreated patients can present with motor symptoms
What is the treatment of schizophrenia?
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.
Why do patients being treated for schizophrenia get parkinsonian symptoms?
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
Where does the nigrostriatal pathway run?
From the substantia nigra pars compacts to the striatum (caudate nucleus and putamen)
So if dopamine promotes movement, why do untreated patients develop catatonia?
Probably due to less GABA binding so loss of inhibitory effect
What is Catalonia?
State of psychogenic motor immobility and behaioural abnormality manifested by stupor
Where does the tuberoinfundibular pathway run?
From the arcuate and periventricular nuclei of hypothalamus to the infundibular region of hypothalamus
What can decreased dopamine in the tuberoinfundibular pathway lead to?
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.
What are some of the difficulties in treating schizophrenia?
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.
What are some factors that indicate a good prognosis with schizophrenia?
Absence of family history Good premorbid function Acute onset Mood disturbance Prompt treatment Maintenance of initiative and motivation
What are some of the health risks / long term problems associated with schizophrenia?
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
