Biological Therapies for Schizophrenia: Drug Therapy

• Drug Therapies

  Most common treatment is antipsychotic drugs; these can be taken typically as tablets or syrups, or for those unable to take medication daily, it is available as injections every 2 to 4 weeks. They can be required in short or long term- some can take a short cause and lose their symptoms, others may need them for life or face the likelihood of recurrence of SCZ.
• Drug Therapies- Antipsychotic Drugs

  They can be divided into typical (traditional) antipsychotics, and newer atypical antipsychotics or second-generation drugs.
• Typical Antipsychotics- Chlorpromazine

  Present since 1950s, can be taken as tablets, syrups or injection- initial doses are much smaller, and it then gradually increases to a maximum of 400 to 800 mg. They work by acting as dopamine antagonists, reducing the action of dopamine by blocking receptors in the synapse of the brain. Initially, the levels build up, but this then reduces. It normalises neurotransmission in key brain areas, reducing symptoms (like hallucinations).
• Typical Antipsychotics- Chlorpromazine

  Additional Information: it is also an effective sedative, believed to have an effect on histamine receptors, though it isn't fully understood. They are also used to calm people with other conditions, often done when people first arrive to hospital and are anxious. Syrups absorb quicker than tablets, making syrup more likely when its used for its sedative properties.
• Atypical Antipsychotics- Overview

  Have been used since 1970s, aiming in developing newer antipsychotics which supress the symptoms of SCZ, but also minimise the side effects. There is a range of atypical antipsychotics, and they don't all work in the same way. Many of which, we are unsure how they work.
• Atypical Antipsychotics- Clozapine

  Developed in 1960s and trialled in 1970s, but withdrawn following deaths of some users from a blood condition. Though they were discovered to be more effective than typical antipsychotics. It is then used when all other treatments fail, though people now have to do regular blood tests. As it can be potentially fatal, it isn't available as an injection. Daily dosage is typically 300 to 450 mg.
• Atypical Antipsychotics- Clozapine (Explanation)

  It binds to dopamine receptors like Chlorpromazine, but in addition it acts on serotonin and glutamate receptors. This is said to help improve mood and reduce depression and anxiety which can lead to improved cognitive functioning. Hence it is prescribed when a person is at high risk of suicide- particularly important as 30 to 50% of SCZ sufferers attempt suicide.
• Atypical Antipsychotics- Risperidone

  More recently developed, present since 1990s. Developed to be as effective as Clozapine but without its serious side effects. In common with others, it can be taken as tablets, syrup, and injections; and the dosage is increased with use. A typical daily dose is 4 to 8 mg, 12 mg is maximum. It binds more strongly to dopamine receptors, meaning its effective in smaller doses- there is evidence to suggest there are fewer side effects than is typical for these drugs.
• AO3: Evidence for Effectiveness

  Thornley et al reviewed studies comparing Chlorpromazine to controlled conditions where SCZ patients received a placebo- their experiences were identical other than the drug taken. Data from 13 trials and 1121 participants showed that chlorpromazine was associated with better overall functioning and reduced symptom severity; also showed that relapse rates were lower.
• AO3: Evidence for Effectiveness

  Benefits of Atypical Antipsychotics: Meltzer concluded that Clozapine is more effective than TAs and other AAs, and that its effective in 30 to 50% of treatment-resistant cases where prior drugs had failed. Though evidence of which drug is most effective is inconclusive as some people respond better to certain drugs than others- though antipsychotics in general are reasonably effective.
• AO3: Serious Side Effects

  Ranging from mild to serious and even fatal. TAs are associated with: dizziness, agitation, sleepiness, weight gain and itchy skin. Long-term use can result in tardive dyskinesia- caused by dopamine supersensitivity, manifesting through involuntary facial movements such as blinking and lip smacking.
• AO3: Serious Side Effects

  The most serious side effect of TAs is neuroleptic malignant syndrome- believed to be caused by the drug blocking dopamine action in hypothalamus. It causes high temperature, delirium and coma; it can be fatal. As doses of TAs decline, so have rates of NMS. It is estimated it can be experienced by 0.1 to over 2%.
• AO3: Theoretical Issue with Dopamine Hypothesis

  Our understanding of antipsychotic drugs are tied to DH in its original model. However, there is now evidence to show this isn't a complete explanation, and that low levels of dopamine in the cortex can lead to symptoms. Therefore, using the modern DH, antipsychotics then shouldn't work- this has then undermined the validity of the idea that antipsychotics work. IDA- Biological Reductionism
• AO3: Problems with Effectiveness Evidence

  Healy suggested that some successful trials have had their data published multiple times, which then exaggerates the evidence of positive effects. Arguing that as they have a calming effect, they can easily be seen as having a positive effect on SCZ sufferers- but they don't often reduce the severity of psychosis. Also, most data published assesses short-term benefits only.
• AO3: The Chemical Cosh Argument

  It is widely believed that antipsychotics can be used in hospital situations to calm people, allowing the staff to interact more easily. Though some claim this doesn't benefit the people themselves. Although the National Institute of Health recommends short-term use of antipsychotics to calm those agitated; Moncrieff argues that this practice is a human rights abuse. IDA- Ethical Implications, Social Sensitivity, Informed Consent