Schizophrenia - Biological Therapies Flashcards
Biological therapies for SZ?
Antipsychotic medication
Types of antipsychotic?
Conventional and Atypical
Which antipsychotic is more widely used?
Conventional (1950s) have now largely been superseded by the new 2nd generation atypical (1990s)
What do antipsychotics do?
Help them function as well as possible in life and increase feelings of subjective wellbeing, but don’t cure SZ
What symptoms to antipsychotics combat?
They can eliminate positive symptoms by reducing stimulation of the dopamine system in the brain (but not negative)
When are antipsychotics taken?
Some individuals have to take a course once whilst others will take regular doses in order to prevent symptoms reappearing to an unacceptable level
Example of a conventional antipsychotic?
Chloropromazine
What does chlorpromazine to do the dopamine system?
Dopamine antagonist - so reduces stimulation and so reduces SZ symptoms
What does chlorpromazine do?
Binds tightly to dopamine receptors (particularly D2) but doesn’t stimulate them - when dopamine is released from neurones it’s unable to bind to the receptors so doesn’t have an effect
What symptoms does chlorpromazine combat?
Positive symptoms such as hallucinations and delusions
Example of an atypical antipsychotic?
Clozapine
What does clozaphine do?
Binds loosely to D2 receptors and then rapidly dissociates, binds to serotonin 5-HT2A receptors to stimulate enough dopamine release to stop motor side effects but not too much so the benefits are still seen
What does dissociation allow for?
Natural dopamine transmission between doses
What symptoms does clozapine combat?
Eliminates positive symptoms and treats negative symptoms
Difference in side effects between antipsychotics?
Atypical have lower levels of side effects so are better tolerated
Strengths of effectiveness of antipsychotics?
Support
Weaknesses of effectiveness of antipsychotics?
Reductionist
Not for everyone
Symptoms not the cause
Support for effectiveness of antipsychotics?
Davis et al
Davis et al?
19% relapse rate on anti-psychoitcs compared to 55% on a placebo (meta-analysis of 29 studies)
Reductionism in effectiveness of antipsychotics?
Vaughn and Leff
Vaughn and Leff?
In a high EE environment relapse was 53% on antipsychotics and 92% on placebo, while no significant different in low EE (12% and 15%)
Research on antipsychotics not being for everyone?
Wahlbeck et al
Wahlbeck et al?
About 30% of patients either don’t respond to antipsychotics or are immune to them, and only about half of resistant patients respond favourably to clozapine
Antipsychotics treating the symptoms not the cause?
Antipsychotics reduce symptoms usually within 6 months but they often return again if medication is stopped
Strengths of appropriateness of antipsychotics?
Lower side effects with atypical
Weaknesses of appropriateness of antipsychotics?
Side effects with conventional
Motivational deficits
Ethical issues
Side effects with antipsychotics?
Hill
Hill?
30% of users taking conventional drugs for 7+ years develop tardive dyskinesia and in 75% of cases this is irreversible
Lower side effects with atypical?
Jeste et al
Jeste et al?
Tardive dyskinesia rates in 30% of people after 9 months of conventional, but in 5% of atypical
Motivational deficits with antipsychotics?
Ross and Read
Ross and Read?
Being prescribed medication reinforces the view that there’s ‘something wrong with you’
Ethical issues with antipsychotics?
‘Chemical straightjackets’ dehumanise and take away personal responsibility/control
Cost-benefit analysis would probably be negative
People with SZ not in proper position to give informed consent
