1: Psychosis and schizophrenia Flashcards
What is a functional hallucination?
Hallucination e.g visual, auditory which only occurs in response to a specific cue e.g a noise or sight
What is the definition of heritability?
Degree of variability in a trait that is caused by genetic differences in a population
Which type of twins are most likely to both develop schizophrenia?
Monozygotic
from the same zygote
Which drug is highly associated with schizophrenia?
Cannabis
Does heroin have a hallucinogenic effect?
No
sedative, analgesic
neither does withdrawal
What is the relationship between age, substance use and schizophrenia?
The younger you start on addictive drugs e.g cannabis, the more likely you are to be addicted AND develop schizophrenia
What happens to the brain grossly in poorly managed schizophrenia?
Enlarged ventricles
Why do the ventricles expand in diseases like Alzheimer’s and schizophrenia?
To fill space left by atrophied brain
Which lobes atrophy in schizophrenia?
Frontal lobe
Temporal lobe
causing negative symptoms
In schizophrenia, (grey / white) matter reduces in size.
grey matter
In schizophrenia, grey matter is lost from the brain.
What causes this?
Reduced connections between neurons
NOT neuronal loss as in Alzheimer’s disease
Which neurotransmitter is implicated in psychosis?
Dopamine
Which addictive drug causes dopamine release in the brain and can worsen schizophrenia?
Amphetamine
Which type of drug is used to treat schizophrenia?
Dopamine receptor antagonists
i.e antipsychotics
Which dopaminergic pathways start at the
a) substantia nigra
b) VTA
c) pituitary gland?
What are they responsible for?
a) Extrapyramidal motor pathway
b) Mesolimbic pathway
c) Prolactin pathway
Movement, motivation/reward and PRL action respectively
What effect do
a) amphetamine
b) dopamine antagonists
have on dopamine receptors?
a) Activation
b) Inhibition
What symptoms of schizophrenia are caused by dopamine
a) hyperactivity
b) hypoactivity?
What does this mean for the effects of antipsychotic drugs?
a) Psychotic (positive) symptoms
b) Negative symptoms
Antipsychotics are dopamine antagonists, so they treat the hyperactive symptoms (psychosis) but NOT the hypoactive (negative) symptoms
What areas of the brain are affected by schizophrenia?
Frontal lobe
Temporal lobes
What are the two main groups of antipsychotic drugs?
Typical (1st generation)
Atypical (2nd generation)
Which side effect do most 1st generation antipsychotics cause?
Extrapyramidal motor symptoms
Which specific dopamine receptor is probably involved in schizophrenia?
D2
Which class of antipsychotics are less likely to cause side effects?
2nd generation
Which neurotransmitters are involved in schizophrenia?
DOPAMINE
Glutamate
Serotonin
What is an example of extrapyramidal motor symptoms caused by antipsychotics?
Acute dystonia - painful spasms
Parkinsonism
Akathisia
Tardive dyskinesia
Which muscles can be affected by acute dystonia after a patient takes antipsychotic drugs?
Neck
Back
Extraocular
How is acute dystonia caused by antipsychotics treated?
Anticholinergics
e.g duloxetine
What is Parkinsonism?
How is it managed?
Parkinsonian symptoms (i.e tremor, bradykinesia, rigidity, postural instability) with no underlying PD
Most commonly caused by drugs (e.g the dopamine antagonists given for schizophrenia)
Managed using anticholinergic drugs
What is akathisia?
Severe restlessness
How is akathisia managed?
Dose reduction of dopamine antagonist
Doesn’t respond to anticholinergics
What is tardive dyskinesia?
Progressive onset of involuntary, repetitive movements
e.g grimacing, tongue rolling
How is tardive dyskinesia managed?
Try dose reduction but sometimes that makes it worse
So you want to avoid tardive dyskinesia in the first place
Doesn’t respond to anticholinergics
Which antipsychotic drug is advised after the failure of two previous 1st/2nd generation drugs?
Clozapine
What is by far the most effective antipsychotic drug?
Clozapine
Clozapine is the most effective antipsychotic drug.
Why isn’t it used first line?
Side effects
What are the need to know side effects of clozapine?
Agranulocytosis
Myocarditis
Clozapine can cause agranulocytosis. Which other drug, covered in 2nd year, can cause this disease?
Carbimazole (anti-thyroid drug)
What are the first signs that a patient taking clozapine has agranulocytosis?
Sore throat
Fever
indicating an URTI that the patient will have major trouble fighting off
How are clozapine patients monitored for agranulocytosis?
Blood tests (for low WCC)…
Weekly for 6 months
Then fortnightly for 6 months
Then monthly thereafter
Apart from agranulocytosis, what is a side effect of clozapine?
Myocarditis
or all the other 2nd generation side effects: metabolic syndrome, increased appetite, sedation, muscarinic blockade…
