Area 5: Biological treatments for schizophrenia

Drug therapy - typical and atypical antipsychotics.

Discuss biological treatments for schizophrenia: Antipsychotics? In what form?

• Anti-psychotics are based on idea that faulty levels of neurotransmitter uptake, specifically dopamine, are responsible for +ve symptoms of schizophrenia.

• They’re available as daily tablets and syrups or as injections every 2-4 weeks.

How is the treatment delivered? (process)

• Only available on prescription from psychiatrist

• Patients will be monitored to ensure they’re responding to drugs correctly

• There are usually several diff variations/brands of drugs + it may be necessary to try several diff ones until drug that suits a particular patient best is found.

• Psychiatrists will adjust quantity of a drug so it’s tailored to level needed for that patient. The patient will gradually need higher and higher doses as their brain responds and adapts to it (a negative consequence of the fact that our brains are plastic)

For schizophrenia the available drugs can be split into two categories:

• Typical anti-psychotics

• A-Typical anti-psychotics

Typical anti-psychotics

used to reduce the effects of dopamine.

A-Typical anti-psychotics

also work on reducing serotonin activity.

Typical Drugs AO1 + e.g. (hint what is schiz caused by -dopamine hypothesis- change must be counteracted)

• E.g. Chlorpromazine been found to reduce acute +ve symptoms (hallucinations + delusions).

• +ve symptoms may come from xs of dopamine at synapse so work by blocking dopamine receptors + reduce +ve symptoms ONLY.

• Drugs occupy receptor sites in dopamine receptor neurons (D2 receptors) + will prevent as much dopamine taken from synapse, they’re an antagonist as they reduce levels of neurotransmitter.

• Will reduce message + prevent stim being enhanced to cause +ve symptoms

• Chlorpromazine is also effective sedative.Believed to be related to effect on histamine receptors. Chlorpromazine used to calm patients when patients are first admitted to hospitals + are anxious.

Atypical Drugs AO1

• Developed more recently in 1970’s + beyond, atypical drugs ( Risperidone and Clozapine).

• They are effective for those unresponsive to typical anti-psychotics although there are still a proportion of schizophrenics unresponsive to any type of drug.

• The main difference in mode of action is that they block serotonin receptors (5-HT2) as well as dopamine ones + block more temporality than typical antipsychotics.

• It’s not yet known specifically how this alleviates symptoms but they work on both +ve and -ve symptoms.

Atypical Drugs AO1 Clozapine

• Clozapine is used when other treatments fail as it’s side effects can be fatal (lowering of white blood cells – disables immune system).

• It binds to dopamine receptors in same way that Chlorpromazine does, but in addition it acts on serotonin + glutamate receptors.

• It’s believed action helps improve mood + reduce depression + anxiety in patients, + may improve cognitive functioning.

• The mood-enhancing effects mean that it’s sometimes prescribed when a patient is considered at high risk of suicide. This is important as 30- 50% of ppl suffering from schizophrenia attempt suicide at some point-

Discuss biological treatments for schizophrenia: AO3 Effectiveness COLE ET AL

• Using double-blind to control for research bias + participant effects. Cole et al randomly assigned 344 patients from 9 hospitals: 3 groups used diff anti-psychotic drugs; 4th was placebo group.

• After 6 wks staff evaluated patients + judged 75% of patients in anti-psychotic drug groups to be much improved compared to 25% of placebo group. ·

• However, as above study suggests some patients don’t respond to antipsychotic drugs. Suggests schizophrenia isn’t wholly explained by biochemical approach.

Discuss biological treatments for schizophrenia: AO3 Effectiveness COLE ET AL: why do we use double blind trials?

Double-blind research using placebos as a comparison to reduce any possible bias / placebo effect shows they are effective.

Discuss biological treatments for schizophrenia: AO3 Effectiveness Lieberman (2003)

• Compared drugs in 52-week randomised, double blind trial of Clozapine Vs Chlorpromazine.

• 80% achieved remission within 1 yr on both forms of medication.

• However median time to 1st remission was 8 wks for atypical clozapine vs. 12 wks for typical chlorpromazine. At 12 wks, clozapine was superior on rating scale measures of symptom severity.

• Clo (a typical) produced fewer side effects than chlor (typical), particularly movement based side effects but theres no significant diff btwn treatments in weight change / glucose metabolism.

• Supports claim that atypical drugs produce less movement based side effects + shows they’re quicker to take effect

Discuss biological treatments for schizophrenia: AO3 Effectiveness of these studies

• These are randomised clinical trials which are regarded as a scientific and unbiased way to assess effectiveness as they avoid experimenter bias + demand characteristics meaning the results of drug trials are trusted, making the treatment a popular choice.

Discuss biological treatments for schizophrenia: AO3 Effectiveness Drugs advantage + disadvantage

• Drugs act relatively quickly allowing stabilisation of patient’s condition during the acute phase of illness.

• However, no antipsychotic drugs work immediately, improvements are slow despite instant effects on neurotransmitter levels, this means other factors must contribute to mental illness than simply biochemical ones.

Discuss biological treatments for schizophrenia: AO3 Effectiveness patients not responding to typical antipsychotic drugs pros + cons

• Some patients do not respond to typical antipsychotic drugs.

• Suggests schizophrenia isn’t wholly explained by biochemical approach.

• Antipsychotic drugs control psychosis and extend the interval btwn relapses but don’t cure the mental illness.

• However, they do improve patients’ lives + can allow them to live relatively independently of medical supervision.

• They also significantly reduce hospitalisation rates which is good for the patient and the NHS in terms of cost and quality of life.

Discuss biological treatments for schizophrenia: AO3 Appropriateness: Typical antipsychotics side effects why? what?

• Liable to produce movement side effects because they mainly block dopamine.

• These side effects sometimes resemble Parkinson’s disease. Parkinson is a neurological condition in which patients lack dopamine.

• Schizophrenics who take typical anti-psychotics + therefore also have reduced dopamine levels suffer from Parkinson’s like tremors and slow movement.

Discuss biological treatments for schizophrenia: AO3 Appropriateness: A-Typical antipsychotics side effects why? what?

• Atypical antipsychotics are less liable to produce movement side effects as they have less action on dopamine system, + instead affect wide range of neurotransmitter systems.

• However A-typical drugs (such as clozapine) do have distressing side effects like significant weight gain + lowering of white blood cells which can result in death + requires regular blood monitoring

Discuss biological treatments for schizophrenia: AO3 Appropriateness: Side effects ethics

Side effects have ethical implications as doctors would not want to cause more harm than the disorder itself and it is also hard to get full informed consent if the patient is delusional at the time of prescription.

Discuss biological treatments for schizophrenia: AO3 Appropriateness: Whats a problem w/ administering drugs to schizophrenia ?

Can be a huge problem w/ schizophrenics who may be paranoid / withdrawn + lacking motivation + monitoring drug taking is difficult.

Discuss biological treatments for schizophrenia: AO3 Appropriateness: What may be better than administering drugs? What’s a disadvantage of this?

• An injection can solve this problem as it only needs to be administered once a month.

• However, this has a high cost for the NHS and so is not always possible.

Discuss biological treatments for schizophrenia: AO3 Appropriateness: Lieberman et al (2005)

• Examined effectiveness of typical + atypical drugs in treating almost 1,500 chronic schizophrenics.

• A huge 75% of patients had discontinued use within 18 months due to intolerable side effects w/ similar rates for both types of drugs.

• Typical drugs were stopped due to muscular disorders (tremors etc.) + A-typical were stopped due to excessive weight gain + sexual dysfunction.

Discuss biological treatments for schizophrenia: AO3 Appropriateness: Lieberman et al (2005)

• Before these drugs, 50% of patients admitted to hospital stayed there for life, where they were treated badly.

• Only 3% of schizophrenics are in hospital, and usually only for a few weeks.

• They’re the most popular form treatment as they reduce symptoms to allow for some degree of functioning becoming possible, but they don’t offer a cure.

• They significantly reduce hospitalisation rates which is good for the patient and the NHS in terms of cost and quality of life.