Biological Therapy

Question 1

What are antipsychotics?

Answer 1

Drugs used to reduce the intensity of symptoms, in particular the positive symptoms, of psychotic disorders like SZ

Question 2

What are typical antipsychotics?

Answer 2

• The first generation of drugs for SZ and other psychotic disorder having being used since the 1950’s they work as dopamine antagonists and include chlorpromazine (taken by tablets, syrup or injection).

Question 3

What are dopamine antagonists + what effect do typical drugs have?

Answer 3

There is a strong association between typical antipsychotics like chloropromazine and the dopamine hypothesis. They act by blocking dopamine receptors in the synapses of the brain, reducing the action of dopamine. This dopamine antagonist effect normalises neurotransmission in key areas of the brain reducing symptoms like hallucinations.

• Sedative effect, used to calm patients (syrup absorbed faster)

Question 4

What are atypical antipsychotics and two examples?

Answer 4

Drugs for SZ developed after typical antipsychotics. They typically target a range of neurotransmitters such as dopamine and serotonin including, clozapine and risperidone. Developed to minimise side effects of the drugs that are used.

• Clozapine- Binds to dopamine receptors also acts on serotonin and glutamate improving mood and reducing depression so diagnosed to those at high risk of suicide (30-50% of people with SZ attempt suicide)
• Risperidone binds stronger so has lower doses and it leads to fewer side effects

Question 5

Brief AO3 for drug treatment?

Answer 5

• Evidence for effectiveness [Thornley et al & Meltzer) HOWEVER, Healy found serious flaws with evidence
• Serious side effects
• Mechanism unclear- we don’t know why they work

Question 6

Strengths of drug treatment?

Answer 6

Evidence to support- Thornley et al reviewed studies comparing effects of chlorapromazine to control conditions. Data from 13 trials with a total of 1121 p’s showed that chlorapromazine was associated with better overall functioning and reduced symptom severity as compared to placebo. Meltzer also concluded the clozapine is more effective that typical antipsychotics as it is effective in 30-50% treatment-resistant case where antipsychotics have failed, we can tell they work.

HOWEVER,

Healy suggested serious flaws with evidence for effectiveness. For example most studies are of short-term effects only and some successful trials have had their data published multiple times exaggerating size of evidence base for positive effects. Positive effect could be due to calming effect this isn’t same as saying they reduce the severity of psychosis. Evidence base is less impressive than it first appears.

Question 7

Limitations of drug treatment?

Answer 7

One limitation is the likelihood of side effects. Typical antipsychotics are associated with a range of side effects including dizziness, agitation, sleepiness, stiff jaw etc. Long term can result in tardive dyskinesia cause by dopamine super sensitivity causing involuntary facial movements. Most serious side effects are neuroleptic malignant syndrome where drug blocks serotonin action in the hypothalamus and can be fatal with a frequency 0.1 to 2%. Can do harm as well as good

Another limitation is we do not know why they work. We understand the mechanism of the strong ties to the dopamine hypothesis the idea that symptoms of SZ are linked to high levels of dopamine activity in the sub cortex this is not a complete explanation. Dopamine levels are sometimes too low instead of high this adds to the arguement of their ineffective they shouldnt work in this case. Antipsychotics may not be best treatment