Biological therapy for schizophrenia Flashcards
What is the most common treatment for schizophrenia
Antipsychotic drugs
What is psychosis
Loss of contact with reality through hallucinations/delusions
-Defining characteristic of schizophrenia
Are anti-psychotics short-term or long term?
Both as depends on the patient
What are typical antipsychotics
Around since 50s e.g clorpromazine
-Dosages have declined over last 50 years
How do typical antipsychotics like chlorpromazine work?
Act as dopamine antagonists and block dopamine receptors in synapses
=normalises neurotransmission in key areas of brain which - symptoms like hallucinations
What are antagonists
Chemicals which reduce the action of a neurotransmitter
How is chlorpromazine also used
As sedative for schizophrenics/anxious patients
-In this case given as syrup
What are atypical antipsychotics
Newer (70s)
-Developed to be more effective in - psychosis with less side-effects
-Don’t all work the same and we don’t know how some work
What is clozapine
Atypical antipsychotic used when other S treatments fail
-Must have regular blood tests as potentially fatal side effects (no injection)
-Daily dosage lower than chlorpromazine
How does clozapine work
Binds to dopamine/serotonin/glutamate receptors= reduced anxiety/depression
So sometimes prescribed when suicidal
What percentage of schizophrenics attempt suicide
40%
What is Risperidone
Newer atypical antipsychotic (90s)
-Designed to be as effective as clozapine - the side-effects
-Maximum dosage of 12 mg
How does risperidone work
Binds to serotonin/DA receptors
-Binds more strongly to DA= can be taken in much smaller doses/less side-effects than other anti-psychotics
Strength of antipsychotics
Evidence for effectiveness
-e.g Thornley (2003) reviewed studies with chlorpromazine/placebo= c more effective
-Meltzer (2012) said clozapine most effective
So seem to work
What percentage of treatment-resistant cases did clozapine work (Meltzer 2012)
40%
Counterpoint to evidence of antipsychotic drugs effectiveness
Evidence-base flawed
-David Healy (2012): Most study only short-term effects
-Some trials had data published many times= exaggerates size of evidence
-May just calm ppl so not really reducing severity of psychosis
Weakness of antipsychotics
Side effects:
Weight gain/dizziness/stiff jaw/sleepiness
-Long term use can= tardive dyskinesia
-Most serious= NMS (high temp/delirium/coma)
So ppl may be scared and not take them
2 weakness of antipsychotics
Don’t know why they work
-Understanding from original DA hypothesis but this is not a complete explanation (e.g sometimes DA is too low)
-Mean most APs shouldn’t work
So some APs may not be best treatment/may be other factors in their success
