S12) 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)
What are some hallucinations experienced in the ‘normal’ population?
- Hypnogogic –experienced when going to sleep
- Hypnopompic – experienced when waking up
What is a delusion?
A delusion is an abnormal belief, outside of cultural norms (unshakeable)
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
Identify the first rank symptoms of schizophrenia
- Auditory hallucinations
- Passivity experiences
- Thought withdrawal, broadcast or insertion
- Delusional perceptions
- Somatic hallucinations
what are some features of auditory hallucinations
o Thought echo – hearing thoughts aloud
o Running commentary
o Third person – multiple voices talking about thepatient
what is passivity hallucinations
Belief that an action or feeling is caused by external force eg psychotic person moving limbs but feel like they’re watching
what are delusional perceptions
Attribution of a new meaning to a normally perceived object
eg red light means the earth will end
what are somatic hallucinations
the sense of being touched when no one is
there
Distinguish between thought withdrawal, broadcast and insertion
- Thought withdrawal – thoughts are being taken out of the mind
- Thought broadcast – thoughts are being made known to others e.g. via radio
- Thought insertion – thoughts implanted by others
Identify some positive symptoms of schizophrenia
Positive symptoms – added symptoms:
- Delusions
- Hallucinations
- Thought disorder
- Lack of insight
Identify some negative symptoms of schizophrenia
Negative symptoms – symptoms that take away from the patient:
- Underactivity
- Low motivation
- Social withdrawal
- Emotional flattening
- Self neglect
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 grey matter, temporal lobe reduction
- fewer oligodendrocytes and fewer thalamic neurones
- Reduced hippocampal formation, amygdala, parahippocampal gyrus and prefrontal cortex
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 is by inhibiting mesolimbic and mesocortical pathways
- main side effects come from blocking other dopamine pathways that you don’t want to block
Describe the mechanism of action of atypical antipsychotics in the treatment of schizophrenia
- Low affinity for D2 receptors
- Milder side effects as dissociate rapidly from D2 receptor
– also block 5HT2 receptors
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 dopamine theory
Evidence for involvement of dopamine in schizophrenia (dopamine too high in schizophrenia)
o Drugs that increase dopamine levels (e.g.amphetamines) induce psychosis
o Drugs that antagonise dopamine treat psychosis (especially those acting at D2 receptors)
what are some side effects of taking anti-psychotic medication
- 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
what are some endocrine side effects of taking anti-psychotic meds
o Since dopamine normally inhibits prolactin release, antipsychotics can lead to increased prolactin levels
▪ Amenorrhea
▪ Galactorrhoea
▪ Decreased fertility
▪ Decreased libido
▪ Osteoporosis (long term)
what are some challenges to treating schizophrenia
→ patients lack insight so just give depot injection
factors associated with good prognosis of schizophrenia
(50% of people do well long term)
No family history
Good premorbid function
Acute onset
Mood disturbance
Prompt treatment
Maintenance of motivation
long term complications of schizophrenia
- 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 (contributing to cardiovascular disease etc.)
describe the nigrostriatal pathway
overall what does a reduction in dopamine do to motility
reduces motility
what is Catatonia
→ state at which someone is awake but does not seem to respond to other people and their environment. They have little reaction to their surroundings.
due to less GABA so less inhibition
what is the criteria for the diagnosis of Catatonia
→ more than 2 weeks of either:
- Stupor / mutism
- Excitement
- Posturing
- Negativism
- Rigidity
- Waxy flexibility
- Command automatism
what is the Tuberoinfundibular pathway
pathways of dopamine involved in schizophrenia
