S11) Psychotic Disorders Flashcards
What is psychosis?
- Psychosis is the presence of hallucinations or delusions
- It describes symptoms, not a diagnosis in itself
What are hallucinations?
- Hallucinations are a perception without a stimulus
- It can be in any sensory modality (visual hallucinations are organic e.g. tumour, eye disease) (auditory hallucinations were the commensest)
What are some hallucinations experienced in the ‘normal’ population?
- Hypnogogic – experienced when going to sleep (commonest, feeling like your name is called)
- Hypnopompic – experienced when waking up
usually auditory
What is a delusion?
A delusion is an abnormal fixed, false belief, outside of cultural norms (unshakeable- they truly believe it)
Identify five organic causes of psychosis
- Delirium caused by infection
- Hypercalcaemia
- Acute drug/alcohol intoxication
- Post-ictal psychosis
- Hyperthyroidism
Identify some iatrogenic causes of psychosis
- Steroids
- L-Dopas
Describe features of schizophrenia (myths to overcome)
Patients with schizophrenia don’t have a split mind or personality - it is a psychotic disorder!
Patients with schizophrenia are generally no more ‘dangerous’ than any other patient.
5% of violent crimes are committed by patients with severe mental illness, which means that 95% are committed by ‘normal people’!
Identify the first rank symptoms of schizophrenia (extremely diverse, manifesting in many diff ways)
- Auditory hallucinations
- Passivity experiences
- Thought withdrawal, broadcast or insertion
- Delusional perceptions
- Somatic hallucinations
Identify examples of auditory hallucinations?
– 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
(voices they here are from the outside, not in their mind!)
What are passivity experiences?
Patient believes an action or feeling is caused by an external force
(felt like arm being moved by something else)
Distinguish between thought withdrawal, broadcast and insertion
- Thought withdrawal – thoughts are being taken out of the mind (feeling like someone else’s thoughts are in their head i.e. not your own thoughts)
- Thought broadcast – thoughts are being made known to others e.g. via radio
- Thought insertion – thoughts implanted by others
What is delusional perception?
‘attribution of new meaning, usually in the sense of self-reference, to a normally perceived object’
New meaning cannot be understood as arising from patient’s affective state or previous attitudes
The perception is real but then correlate it with something delusional
What are somatic hallucinations?
Mimics feeling from inside the body
– physical bodily sensations - e.g. a lady felt like a hamster was living insider her or e.g. the sense of being touched when noone is there.
Identify some positive symptoms of schizophrenia
Positive symptoms – added symptoms:
- Delusions
- Hallucinations
- Thought disorder (problem with organization of thoughts)
- Lack of insight
(ADDED SYMPTOMS)
Far better at treating positive symptoms than negative symptoms
Identify some negative symptoms of schizophrenia
Negative symptoms – symptoms that take away from the patient:
- Underactivity
- Low motivation
- Social withdrawal
- Emotional flattening
- Self neglect
(SYMPTOMS THAT TAKE AWAY FROM THE PT)
How can all patients with Schizophrenia be different?
– While patients with Schizophrenia might have the same cluster of symptoms e.g. delusions, hallucinations, absence of insight.
– How each patient experiences these symptoms will be completely different e.g.
- Delusions MI5 are following them
- Delusions witchcraft is being performed on them
- Delusions family are poisoning them
Describe the possible mechanisms for pathophysiology of Schizophrenia.
Dopamine pathways
Brain changes
Limbic system
Describe the dopamine theory of Schizophrenia.
– Drugs e.g. amphetamines which cause the release of DA induces psychotic symptoms.
– All medications that antagonise DA receptors (blocks D2 receptors) help treat psychosis & those with the strongest affinity to D2 receptions are most clinically effective.
– 4 DA pathways in the brain: mesocortical/ mesolimbic/ nigrostriatal (involved in Parkinson’s disease) / tuberoinfundibular pathways.
Describe the involvement of dopamine in schizophrenia?
– Drugs that increase dopamine levels (e.g.
amphetamines) induce psychosis
– Drugs that antagonise dopamine treat psychosis (especially those acting at D2 receptors)
Identify the 4 examples of dopaminergic pathways.
– Mesolimbic pathway
– Mesocortical pathway
– Nigrostriatal
– Tuberoinfundibular pathways.
Describe the role of the Mesolimbic pathway and Mesocortical pathway in Schizophrenia.
Mesolimbic pathway → thought to be overactive in schizophrenia (too much dopamine - mainly responsible for positive symptoms: hallucinations and delusions) - need to block dopamine in that pathway - use dopamine blockers
Mesocortical pathway → thought to be in underactive in schizophrenia (responsible for the most negative symptoms - harder to treat as the dopamine levels are much lower here, so when trying to combat the positive symptoms by using dopamine blockers, it enhances the negative symptoms)
Describe the mesolimbic pathway.
From Ventral tegmental area
To Limbic structures (amygdala, septal area, hippocampal formation) and Nucleus accumben
Describe the mesocortical pathway.
From Ventral tegmental area
To Frontal cortex and Cingulate cortex
Describe the common brain changes seen in Schizophrenia
Note: can’t do this scan to confirm the diagnosis though
– Enlarged ventricles
– Reduced grey matter (with reduced brain weight)
– Decreased temporal lobe volume
– Reduced hippocampal formation, amygdala, parahippocampal gyrus and prefrontal cortex
In the ICD10 diagnosis of schizophrenia, a patient with schizophrenia must present with at least one of which symptoms?
A) Thought echo, insertion, withdrawal, broadcast
B) Delusions of control, influence or passivity
C) Hallucinatory voices
D) Persistent delusions that are culturally inappropriate and completely impossible
In the ICD10 diagnosis of schizophrenia, a patient with schizophrenia must present with at least two of which symptoms?
E) Persistent hallucinations in any modality, occurring every day for at least one month
F) Neologisms, breaks or interpolations in the train of thought, resulting in incoherent/irrelevant speech
G) Catatonic behaviour
H) Negative symptoms e.g. marked apathy, paucity of speech, incongruity of emotional responses
Identify the different types of schizophrenia
- Paranoid schizophrenia
- Simple schizophrenia
- Hebephrenic schizophrenia
- Undifferentiated schizophrenia
- Catatonic schizophrenia
What is paranoid schizophrenia?
Paranoid schizophrenia – delusions or hallucinations prominent
What is simple schizophrenia?
Simple schizophrenia:
- Loss of drive and interest, aimlessness, idleness, self absorbed attitude and social withdrawal
- No hallucinations/delusions
What is hebephrenic schizophrenia?
Hebephrenic schizophrenia – definite and sustained flattening or shallowness of affect or incongruity/inappropriateness of affect, aimless and disjointed behaviour or thought disorder affecting speech
What is undifferentiated schizophrenia?
Undifferentiated schizophrenia – insufficient symptoms to meet criteria of any subtypes or so many symptoms fit more than one criteria
In the pathophysiology of schizophrenia, which two brain pathways are thought to change?
- Mesolimbic pathway – thought to be overactive in schizophrenia
- Mesocortical pathway – thought to be underactive in schizophrenia
Describe the course of the mesolimbic pathway
- From: ventral tegmental area
- To: limbic structures (amygdala, septal area, hippocampal formation) and nucleus accumbens
Describe the course of the mesocortical pathway
- From: ventral tegmental area
- To: frontal cortex and cingulate cortex
Describe the brain changes observed in schizophrenia
- Enlarged ventricles
- Reduced hippocampal formation, amygdala, parahippocampal gyrus and prefrontal cortex
- Decreased grey matter
- Decreased temporal lobe volume
- Reduced size of limbic structures and prefrontal cortex
- Changes at synapses
- Fewer oligodendrocytes
- Fewer thalamic neurones
▪ Possible role of basal ganglia
- Some schizophrenics show movement disorder features
Describe 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.
Describe the other possible theories for 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 are the two options for treating schizophrenia?
- Typical antipsychotics
- Atypical antispychotics
Describe the mechanism of action of typical antipsychotics in the treatment of schizophrenia
- Block D2 receptors in all CNS dopaminergic pathways
- Main action as antipsychotics by inhibiting the mesolimbic and mesocortical pathways
- Side effects come from blocking other pathways (e.g. nigrostriatal)
Note: v potent, they cause a lot of side effects: tardive dyskinesia (it is permanent! even when drug is stopped and no effective treatment for it) more parkinsonian side effects)
Describe the mechanism of action of atypical antipsychotics in the treatment of schizophrenia
- Lower affinity for D2 receptors
- Milder side effects as dissociate rapidly from D2 receptor
- Also block 5HT2 receptors (so some action on serotonin systems)
More commonly used.
Note: side effect: increase appetite and gain weight, sedation
There are 5 different dopamine receptors in the brain. Which one is said to be the most important target for psychosis and Schizophrenia.
D2 receptor
What are the problems in the treatment of Schizophrenia?
Antipsychotic medications cause side effects!
If you block the dopamine in the nigrostriatal pathway → you get Parkinsonian symptoms - shuffling gait, mask like face, rigidity, tremors, cogwheeling
Less dopamine = less movement
When you stop the drug, the symptoms get bigger but Schizophrenia is an illness so we don’t want to stop the treatment.
Describe the course of the Nigrostriatal pathway?
From: Substantia nigra pars compacta
To: Striatum (caudate nucleus and putamen)
What are the side effects of antipsychotics - dopamine antagonists?
– Can affect movement due to involvement of nigrostriatal pathways (similar to Parkinson’s disease)
– However, untreated patients can also develop hypokinetic movement disorders (catatonia) → might be caused by involvement of GABA
Endocrine side effects
– Since dopamine normally inhibits prolactin release, antipsychotics can lead to increased prolactin levels
- Amenorrhea
- Galactorrhoea
- Decreased fertility
- Decreased libido
- Osteoporosis
What happens if we have lack of dopamine?
Less movement
What is Catatonia?
Catatonia is a psychomotor syndrome that has been reported to occur in more than 10% of patients with acute psychiatric illnesses.
So if dopamine promotes movement, why do untreated patients develop catatonia?
– More than two weeks, one or more of:
- Stupor / mutism
- Excitement
- Posturing
- Negativism
- Rigidity
- Waxy flexibility
- Command automatism
Probably due to less GABA binding so loss of inhibitory effect
Describe the course of the tuberoinfundibular pathway.
From: Arcuate and periventricular nuclei of Hypothalmus
To: Infundibular region of hypothalamus
What hormone level rises when dopamine antagonists are given?
– Dopamine normally inhibits prolactin release from the pituitary
– DA antagonists, which lower DA lead to loss of DA’s inhibitory function, and .: increased prolactin levels
– This can lead to amenorrhoea, galactorrhoea, decreased fertility, reduced libido and long term can lead to osteopenia/ osteoporosis
What are the difficulties treating people with SCZ?
– Lack insight (don’t realise they are unwell .: don’t take meds/ lack compliance) - to get around this can be given as a depot injection (only needs to be done once in a month)
– Medications therefore often not taken (.: when people are well - recovered from an acute psychotic episode, often left with negative symptoms which includes reduced motivation, energy)
– Medications can be given in different ways: PO (inc orodispersible- melt in the mouth tablet), short acting IM, depot (long acting, infection then tablets doesn’t have to be taken for the rest of the movement).
What is drug induced psychosis?
Drug induced psychosis is a form of psychosis induced by a psychoactive substance
Provide examples of drugs that can induce psychosis
- Methamphetamine
- Cannabis
- Cocaine
- Amphetamines
- Ketamine
What is the ICD10 criteria for drug induced psychosis?
- Onset of psychotic symptoms during or within two weeks of substance use
- Persistence of the psychotic symptoms for more than 48 hours
- Duration of the disorder ≤ six months
What is the prognosis of SCZ?
– Earlier someone is treated the better the prognosis.
– About 50% will do well ling term
– Good prognostic factors
What are the factors associated with good prognosis of Schizophrenia?
– No/ Absence of family history
– Good premorbid function
– Acute onset
– Mood disturbance
– Prompt treatment
– Maintenance of initiative and motivation
Describe the long term complications of 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
