Biological Therapy For Schizophrenia

Question 1

What is Drug therapy?

Answer 1

• The use of antipsychotic drugs
• a person with psychosis experiences some loss of contact with reality e.g hallucinations/delusions (a defining characteristic of schizophrenia)
• Some can take them for a short time and symptoms wont return, other for life
• Can be divided into typical and newer atypical

Question 2

What are ‘Typical antipsychotics’?

Answer 2

• around since 1950s e.g chlorpromazine which can be taken as tablets, syrup, injection
• if taken orally, administered daily max dose of 1000mg (initially smaller doses and increased)
• Doses have declined over the last 50 years

Question 3

What are Dopamine Antagonists?

Answer 3

• strong association between typical APs (antipsychotics) and the dopamine hypothesis
• antagonists are chemicals which reduce actions of a neurotransmitter
• dopamine antagonists block dopamine receptors in the synapses in the brain
• initially DA levels build up but production is then reduced
• according to DA hypothesis of Sz this dopamine-antagonist effect normalises neurotransmission in key areas, reducing symptoms e.g hallucinations

Question 4

What is the Sedation Effect?

Answer 4

• Chlorpromazine is an effective sedative, related to its effect on histamine receptors but not fully understood
• used to calm individuals, often done when patients are first admitted too hospital and are anxious
• syrup is absorbed faster than tablets so it tends to be given when Chlorpromazine is used for sedation

Question 5

What are atypical antipsychotics?

Answer 5

• 1970s aim was to improve effectiveness in suppressing symptoms of psychosis and minimise side effects
• range of atypical antipsychotics and they don’t all work in the same way

Question 6

What is Clozapine?

Answer 6

• Used when other treatments fail, patients have to take regular blood tests to check not developing agranulocytosis (side-effect)
• because potentially fatal side effects not available for injection, 300-450mg daily
• bind to dopamine receptors but also acts on serotonin and glutamate receptors, helps improve mood and reduce depression, anxiety and improves cognitive function
• mood-enhancing effect means individual is considered at high risk of suicide, 30-50% of people with Sz attempt suicide

Question 7

What is Risperidone?

Answer 7

• attempt to produce a drug as effective as clozapine without serious side effects
• tablets, injections, or syrup
• small dose initially built up to 4-8mg with a max of 12mg
• bind dopamine serotonin receptors, binds more strongly to dopamine receptors than clozapine and more effective in smaller doses - leads to fewer side effects

Question 8

What research supports effectiveness?

Answer 8

• Thornley reviewed studies comparing effects of chlorpromazine to control conditions, 13 trials total of 1121 pps showed chlorpromazine was associated with better functioning and reduced symptom severity as compared to placebo

Question 9

What is a limitation of the evidence for effectiveness?

Answer 9

• Healy suggested flaws with evidence for effectiveness, most studied are of short term effects and some successful trials have had data published multiple times, exaggerating the effect
• Because antipsychotics have calming effects, it’s easy to demonstrate they have on those with Sz, does not necessarily mean they reduce severity of psychosis

Question 10

What are the negative impacts of antipsychotics?

Answer 10

• side effects e.g dizziness, agitation, sleepiness, weight gain and itchy skin
• finally neuroleptic malignant syndrome, caused when drugs block dopamine actions in the hypothalamus, can be fatal