Biological Therapies - Antipsychotic Drugs

A01: Antipsychotic drugs

Drugs that are effective in treating sz are called anti-psychotics or neuroleptics. Prior to their introduction in the 1950’s, there was no effective treatment for sz.

Antipsychotic drugs are not a cure, but help the patient function as well as possible in their life, as well as increasing their feelings of subjective wellbeing.

Conventional (typical) - Antipsychotic Drugs

Conventional (typical) antipsychotics - such as chlorpromazine- are used primarily to combat positive symptoms of sz, which are - products of an overactive dopamine system.

• Can be taken in tablet form, as a syrup or by long-lasting injection (every 2-4 weeks).

• Symptoms such as hallucinations and agitation tend to reduce within a few days but delusions typically take a few weeks.

• They are usually used alongside psychological therapies such as CBT.

Typical Antipsychotic drugs (conventional)

• AKA conventionals - first generation antipsychotics (used since 1950’s) address POSITIVE SYMPTOMS ONLY.

• E.g. Chloropromazine, combat (battle) positive symptoms.

• Dopamine antagonists (reduce action)

• Bind tightly to dopamine receptors (particularly D2 in mesolimbic pathway, blocking the action + normalising and neurotransmission

• Have a sedative effect as it effects histamine recptors - calm indivoduals

• Between 60-75% of D2 receptors must be blocked for the drugs to be effective and happens in several areas of the brain; which explains severe side effects

Atypical antipsychotic drugs

• Newer, second generation (developed 70s, widely used since 90s, fewer side effects, faster outcome for patients having first psychotic episode)

• Address POSITIVE + NEGATIVE symptoms

• Have lower affinity and occupancy for dopamine receptors; bind to D2 receptors but then rapidly dissociate, permitting the anti-psychotic effect without motor side effects.

• They also have a high degree of occupancy of some serotonin receptors, rebalancing this neurotransmitter.

• Example: Clozapine attaches loosely to specific D2 dopamine receptors (blocking effects is temporary = less serious side effects, allowing some dopamine transmission).

• Also acts serotonine and glutamate receptors which helps improve mood and reduces depression (particularly useful for suicidal + negative symptoms).

A03: Compliance

Some patients refused to comply with drug treatment because of the poor side effects or poor memory.

Research has indicated that if antipsychotic drugs are stopped suddenly symptoms recur (Davis et al 1993).

This has led to the revolving door syndrome of discharge into the community followed by readmission to hospital.

One way of solving this problem is to administer the drug by depot injection which releases the medication slowly over a period of weeks.

A03: Success

Drug therapy for SZ has proved itself to be effective than any other form of therapy in the treatment of this serious mental disorder.

However, there are individual differences in responses to drugs and even the newer atypicals are not effective with all schizophrenics.

AO3: Palliative treatments

Drugs therapy is a palliative treatment - is suppresses the symptoms without addressing the underlying processes.

This can mean that patients have to take the drugs for many years

AO3: Are placebo studies a fair test?

Ross and read (2004) → argue that placebo studies are not a fair comparison of treatment versus non-treatment because, under the placebo conditions, the patient is actually in a drug withdrawal state.

With sudden and complete withdrawal of antipsychotic medication, the previously blocked dopamine system becomes flooded with dopamine because of the heightened sensitivity and increased number of dopamine receptors (which happen as a response to a drug-induced blockade of the dopamine system during medication).

This results in totally overwhelming the dopamine system. Consequently, claim Ross and Read, a proportion of relapses in placebo conditions can be explained by the withdrawal effects of the drug.

AO3: Problems with the studies

Healy (2012) has suggested some successful trials have had their findings published multiple times exaggerating the positive effects of anti-psychotics.

He also suggests that as they have a calming effect it is easy to show that they help patients, which is not the same as showing that they reduce the severity of psychosis.

Indeed, there are many who see the widespread use of anti-psychotics as fuelled by powerful pharmaceutical companies.

AO3: Ethical issues: An inhumane treatment?

The problem associated with the use of antipsychotic medication raises significant ethical issues.

Some refer to widespread use of drugs to treat sz as ‘chemical straightjackets’ - they are dehumanising and take away any sense of personal control as they are used to calm patients.

The issue of informed consent should also be considered.

The possible exploitation of drug therapies has been raised by Moncrief (2013) who proposed the chemical cosh argument which suggested which suggested that hospital staff likely could be over administering sedative anti-psychotics in order to make their patients easier to deal with.

AO3: Are typical antipsychotics effective? - Revolutionary treatment

The development of anti-psychotic revolutionised treatment of sz, rapidly reducing the most disturbing symptoms (compared to psychological therapies) and decreasing time spent in hospital, enabling patients to live a relatively normal life. Less than 3% of patient with sz live permanently in hospital

AO3: Are typical antipsychotics effective? - Relapse rates are lower

Studies that have evaluated the effectiveness of antipsychotic medication have done so by comparing relapse rates of those on medication with those on a placebo.

• Thornley et al (2003) → reviewed studies comparing the effects of chlorpromazine to control conditions.

• Data from 13 trials with a total of 1121 pps showed that chlorpromazine was associated with better overall functioning and reduced symptoms severity as compared to placebo.

AO3: Are typical antipsychotics effective? - Other important factors may affect relapse

One of the studies in a review by Davis et al (1989) found antipsychotic medication did make a significant difference but only for those living iwth hostility and criticism (53% relapse compared to 92% in placebo).

For those living in more supportive home environments there was no significant difference.

AO3: Are typical antipsychotics appropriate? -side effects

• Conventional antipsychotics produce some very serious side effects which raise doubts about their appropriateness as a treatment including tardive dyskinesia which is caused by dopamine supersensivity and causes involuntary facial movements such as grimacing, blinking and lip-smacking.

• Incidence of TD as a side effect of conventional antipsychotics is 30% and irreversible in 75% of these cases (Hill, 1986)

• Most serious side effect is neuroleptic malignant syndrome which is believed to be caused when the drug blocks dopamine action in the hypothalamus, an area in the brain associated with the regulation of a number of body systems. NMS results in high temperature, delirium and coma and can be fatal - antipsychotics can do harm, therefore ppl may avoid taking it (inaffective treatment)

• These side effects can be so distressing that other drugs have to be given to control them or the patient may stop taking them and their symptoms recur.

AO3: Are typical antipsychotics appropriate? - motivation

Ross and Read (2004) argue being prescribed medication reinforces the view ‘there is something wrong with you’ which prevents the individual thinking about potential stressors, reducing their motivation to alleviate these stressors by finding possible solutions themselves which would not come with risks of side effects.

AO3: Are Atypical antipsychotics effective? - Evidence supporting effectiveness of atypicals

Meltzer (2012) concluded that clorapine is antipsychotics and other atypical antipsychotics, and that it is effective in 30-50% of treatment-resistant cases where typical antipsychotics have failed. This means that antipsychotics work.

AO3: Are Atypical antipsychotics effective? - Evidence contradicting effectiveness of atypicals

Counterpoint: Crossley et al (2010) → carried out a meta-analysis and found no significant difference between typical and atypical drugs in terms of their effects on symptoms, but did note differences in the side effects (atypical more weight gain, but less extrapyramidal effects).

Healy (2012) → suggested serious flaws with evidence for effectiveness. e.g. most studies are of short-term effects only and some successful trials have had their data published multiple times, exaggerating the size of the evidence base of positive effects. Antipsychotics also have powerful calming effects, it is easy to demonstrate that they have some + effects on people experiencing symptoms of sz. This is not the same as saying they really reduce the severity of psychosis - means that the evidence base for antipsychotic effectiveness is less impressive than it first appear.

AO3: Are Atypical antipsychotics appropriate? - There are fewer extrapyramidal side effects

A key advantage of atypical is that patients experience fewer side effects, particularly extrapyramidal, which means patients will continue with their medication.

AO3: Are Atypical antipsychotics appropriate? - But there are side affects

Counterpoint:

However, there are still side effects, and it is therefore still a significant weakness of atypical anti-psychotics. For instance, some patients experience a reduction of white blood cells, a condition called Agranulocytosis. → reduction of white blood cells (making an individual vulnerable of infection; because of this can only be taken as daily dose, not by injection and those taking it have regular blood tests) 1-2% of patients taking clozapine develop this.