biological treatments schizophrenia

7/30/2019 Biological Treatments schizophrenia

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Schizophrenia:Biological Treatments

Antipsychotic MedicationConventional/Atypical Antipsychotics

Conventional/Atypical


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SchizophreniaBiological Treatments: ECT

First introduced as a treatment for Sz on the falseassumption that inducing an epileptic fit would removethe symptoms of Sz, as the two conditions cannot existtogether.

ECT involves the application of an electric voltageacross the brain. It works best when applied bilaterallyand is given in conjunction with anaesthetic and a muscle

relaxant.

However, its effectiveness is minimal and only short-term (20-50% relapse after 6 months).


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Though ECT is no more dangerous than minor surgeryperformed under anaesthetic, it is thought to beunethical:

1. It can seem brutal and perceived by patients as apunishment for the condition

2. We must consider whether patients in theirmentally disordered state are truly able to give

informed consent for the treatment.

Q. If no truly informed consent can be gained why doyou think the treatments still go ahead?


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Recently ECT has been reintroduced as a treatmentfor Sz; though it is more effective than placebos - itis still not as effective as drug treatments and so is

often only used as last resort if patients do notrespond positively to antipsychotics (Tharyan &Adams, 2005).

Q. what does this say about its appropriateness?

ECT no longer commonly used due to the directeffect of antipsychotics which have revolutionisedtreatment of Sz.

l (1


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Conventional (1stgeneration)Anti-psychotics:

Chlorpromazine Dopamine Antagonists that bind to dopamine

(D2) receptors without stimulating them in

order to block their action = reduce +symptoms (also marked cognitive &behavioural improvement found).

Targets + symptoms of Sz e.g Hallucinationsand thought disturbances = the result ofoveractive dopamine


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Evidence for Effectiveness (I)

Comparison of those on antipsychoticmedication v placebo.

Davis et al (1989): Meta-analysis (AO3) 100studies = > than 70% of sufferers treatedwith antipsychotics improved after 6 weeks v25% on placebo. Suggesting thatantipsychotics do have a beneficial medicaleffect.Motivated sample (I)? Ethics of placebos (I).IF it is a Biological condition they would needthe drug they are being denied.


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However.

Antipsychotics did make a difference in thosefrom negative or hostile environments

Davis et al (1989) Meta-analysis (AO3).

ThoughRoss & Read argues this is not faircomparison as in placebo conditions pp is indrug withdrawal state if antipsychotics

stopped, dopamine system = flooded =negative side effects/symptoms e.g. TardiveDyskinesia. They also point out that 25% DIDbenefit from placebo!!


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Appropriateness (I)

Conventional antipsychotics have many worrying sideeffects = Tardive Dyskinesia.

Approx 30% develop TD and it is irreversible in 75%of cases. Approx 24% develop this after takingneuroleptics for 7 years.

Can lead to non-adherence

more likely to relapseand > likely to return to hospital. To combat patients

sometimes given long lasting injections which takesaway their option to discontinue medication (I =ethics)


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Appropriateness (I)

Ross & Read = Giving patients medication gives them acause to stop looking for real treatment & preventsthem addressing possible stressors that might in factbe the cause of Sz; Ethics (I).


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Atypical (2nd generation)Anti-Psychotics: Clozapine

Act by blocking the transmission ofSerotonin into the brain and temporarily

occupying D2 receptors = targets symptoms e.g. < emotional expression.

They then rapidly dissolve to allow normaltransmission.


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Atypical (2nd generation)Anti-Psychotics: Clozapine

These characteristics of atypicalantipsychotics are thought to be the reason

for lower levels of side effects compared toconventional antipsychotics; however, it isnot clear as to how they affect the brain toalleviate the symptoms.


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Effectiveness (I)

Kahn et al (2008): Compared 1st/2nd generationantipsychotics = in general antipsychotics areeffective for at least 1 year BUT 2nd generation(atypical) drugs are not necessarily any > effectivethan 1st generation drugs.

Lieberman et al (2005): Examined the effectivenessof 1st/2nd generation antipsychotics in treating 1,432chronic Szs = 74% patients discontinued treatmentwithin 18 months due to intolerable side effects. 1stgeneration = muscular disorders/2nd generation =weight gain and metabolic effects (I).


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Effectiveness (I)

Meta-analysis (Leucht) found thatsuperiority over conventional antipsychotics= only moderate effect. Out of the new

drugs tested only 2 wereslightly

more

effective; the other 2 were no moreeffective.


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Appropriateness(I)

Despite this Jeste: Tardive Dyskinesia in 30%after 9 months with conventional v 5% withatypical antipsychotics highlighting usefulness

(I) of atypical antipsychotics. With fewerside effects pps likely to persevere withmedication and thus see more benefits.

However, approx 30% of patients either donot respond to treatment or are intolerant tothem.


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Appropriateness (I)

However, approx 30% of patients either donot respond to treatment or are intolerant tothem.

Though Clozapine can sometimes be effectiveWith such treatment resistant patients, onlyabout half respond favourably = the majorityof Patients with chronic Sz cannot be helped

with antipsychotics.


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Appropriateness

Although there is evidence to suggestatypical antipsychotics are somewhateffective in treating Sz = ethical issues (I)

regarding use are raised by critics AS ifpsychological factors are taken into account acost-benefit analysis of advantages would benegative (Lieberman et al, 2005).


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Appropriateness

Regulation & monitoring of antipsychotic drugs isvital. It has been found that doses ofantipsychotics are sometimes too high (see below)

Because they have not been reduced to amaintenance level after the acute stage is over.

This exposes patients to unnecessary risks of sideeffects. However, it is sometimes difficult forclinicians to gauge the appropriate dosage. Somepatients do not require medication maintenancemedication after the acute stage, while othersquickly relapse without it.


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Overall Evaluation

Atypical antipsychotics are generally more effective,are relatively cheaper to produce, are easy toadminister & have a positive effect on manysufferers.

However, there is a considerably high relapse ratethrough not sticking to medication regimes (or justnot effective for some people).

Antipsychotics can have serious side effects =Tardive Dyskinesia.


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Conclusion

Biological therapies used to treat Sz suggest abiological approach in terms of explanation whichhighlights the role of physical factors andneurotransmission as the cause.

However, the treatment aetiology fallacy states thatthe fact that drugs alleviate the symptoms does notmean they are treating the cause.

Thus, suggesting only one cause is Deterministic&raises the question ofFreewill in terms of control ofthe disease = psychologically damaging. Maybe amore combined approach would help e.g. socialapproach too?


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Exam Question

Discuss two or more biologicaltreatments for Schizophrenia

(8 + 16 marks)


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How to revise this topic!

Dont forget to remember to mention HOW eachmethod works on the brain in order to target Szsymptoms.

Also, it is important to focus on the effectiveness(quantitative evidence is impressive here) and theappropriateness of each method.

Remember, tell a story

make it interesting for thereader to want to continue. If it is not interesting, itwill make less sense to them.

biological treatments schizophrenia

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