L1 Schizophrenia - 30/9 Flashcards
What is the incidence of schizophrenia?
Effects 1% of the population
What does schizophrenia mean?
Splitting of psychic functions
What was schizophrenia originally thought to be?
A breakdown of integration between emotion, thought and action.
List symptoms of schizophrenia
Bizarre delusions
Hallucinations (visual and auditory)
Incoherent thought
Delusions of grandeur
Paranoid delusions
Feeling disconnected from emotion
Disorganised speech
What was RD Laing’s view of schizophrenia?
Argues that many people labelled as “sane” are still alienated but blend in because they act like everyone else. On the other hand, individuals who show forms of alienation that don’t fit the societal norm are often labelled as “mad” or “bad.”
What is Freud’s theory of schizophrenia?
Paranoid delusions result from repressed sexual urges which are striving for expression.
What are the concordance rates for schizophrenia in monozygotic twins and dizygotic twins?
MZ - 45%
DZ - 10%
What does a 45% MZ concordance rate show?
That there must be other factors than genes such as: infections, autoimmune reactions, toxins, traumatic injury, and stress.
Give an example of a specific environmental stressor.
Bullying - linear increase in severity and frequency of psychotic symptoms with increase in severity and frequency of bullying.
How did the use of chlorpromazine to treat schizophrenia?
It was originally marketed as an anti-histamine. French surgeon noticed it calmed normal patients when used as an anti-inflammatory. Decided it might calm schizophrenics
Discuss reserpine?
Taken from snake root plant
Used to treat mental illness in India
Also effective in treating schizophrenia
What are the similarities of Reserpine and Chlorpormazine?
Both take 2-3 weeks of medication to work.
Symptoms like those in Parkinson’s disease start to emerge - it was then discovered that Parkinson’s disease was due to a loss of DOPAMINE da in the nigro-striatal pathway.
What is the mode of action for Reserpine against dopamine?
Reserpine depletes vesicles so reduce amount of DA that can be released by popping the vesicles so dopamine floats in the cell and can’t go anywhere.
What is the mode of action for chlorpromazapine?
Blocks DA receptors so stops the DA working. Dopamine antagonist (false transmitter) so DA can’t get to the receptors itself.
What is the other evidence for DA hypothesis?
Cocaine psychosis + amphetamine psychosis (Caused by prolonged use) block the reuptake of dopamine so leaves more in the synapse.
What is the efficacy of an anti-psychotic drug correlated with?
It’s ability to bind to DA receptors
What is the exception in this case?
Initially haliperidol appears that it doesn’t bind to the dopamine receptors but upon a closer look you can see it does bind to D2.
What is haliperidol?
A very potent anti-psychotic medication.
What do typical antipsychotics bind to?
Just bind to D2
What do atypical antipsychotics bind to?
Other receptors like D4
What are DA receptors?
Metabotropic receptors (a cell surface receptor that activates a secondary messenger system when a transmitter binds to it).
Describe the groups of DA receptors.
2 families. D1 which includes D1 and D5, and D2 which includes D2, D3, D4.
Describe the relationship of the D1 family of DA receptors to adenlyate cyclase.
Positively coupled to adenlyate cyclase
Describe the relationship of the D2 family to adenlyate cyclase
Negatively coupled.
