Biological Therapies For Schizophrenia

Question 1

What’s the common treatment for SZ

Answer 1

Antipsychotic Drugs

Question 2

What are the two types of antipsychotic drugs

Answer 2

Typical
Atypical

Question 3

What are typical antipsychotics

Answer 3

Dopamine antagonists which work by reducing the effects of dopamine and thus reduce the positive symptoms of SZ

Question 4

How do typical antipsychotics work?

Answer 4

By binding to but not stimulating dopamine receptors (D2 receptors in the mesolimbic dopamine pathway) to block their action and reduce positive symptoms of SZ

Question 5

Example of TYPICAL ANTIPSYCHOTICS

Answer 5

Chlorpromazine
Which can be taken as a tablet, syrup or injection

Question 6

What are atypical antipsychotics

Answer 6

Drugs used to improve the effectiveness of typical antipsychotics and minimise side effects occurring when given typical antipsychotics

Question 7

How do atypical antipsychotics work differently

Answer 7

They only temporarily occupy the D2 receptors and then rapidly dissociate to allow normal dopamine transmission

Question 8

Examples of atypical antipsychotics

Answer 8

Clozapine & risperidone

Question 9

Strengths of effectiveness of antipsychotic drugs in treating SZ (the evidence)

Answer 9

Thornley et al (2003) compared the use of chlorpromazine (typical antipsychotics) with a placebo. Data from 13 trials with a total of 1121 pps showed that chlorpromazine was associated with reduced symptoms and better overall functioning. Furthermore, data from three trials with a total of 512 pps showed that relapse rate was also lower when chlorpromazine was taken. This study this shows that typical antipsychotics were effective in reducing the symptoms of SZ compared to a placebo showing that drug therapy is appropriate in treating SZ.

There is also research evidence to support the appropriateness of atypical antipsychotics. In a review by Meltzer (2012), he concluded that Clozapine (atypical antipsychotics) is more effective than typical antipsychotics and other atypical antipsychotics in treating SZ. In fact Clozapine was seen as effective in 30-50% of cases where typical antipsychotics had failed. This study shows that use of clozapine as a treatment for SZ is a very appropriate drug as Meltzer clearly showed especially when other drugs failed!

Question 10

(+) evidence to support relapse rates being lower when antipsychotic drugs taken

Answer 10

Leucht et al. (2012) carried out a meta-analysis of 65 studies, published between 1959 and 2011, and involving nearly 6000 patients. Some patients were taken off their antipsychotic medication and given placebos instead. Within 12 months, 64% of those patients who had been given the placebo relapsed whereas only 27% relapsed when on antipsychotic medication. The results of this study clearly show that antipsychotic medication is both effective and appropriate in preventing a schizophrenic patient from relapsing.

Question 11

Weaknesses of drug therapy in treating side effects

Answer 11

• side effects e.g. mild -> fatal
• ethical issues

Question 12

More about the side effects of drug therapy (-) e.g. NMS, tardive dyskinesia etc

Answer 12

For typical antipsychotics, the side effects include: dizziness, agitation, sleepiness, stiff jaw, weight gain and itchy skin. A more profound side effect can result in ‘tardive dyskinesia’ which is caused by dopamine supersensitivity and manifests as involuntary facial movements such as grimacing, blinking and lip smacking.
The most serious side effect of typical antipsychotics is NMS (neuro malignant syndrome – area of the brain associated with the regulation of a number of body systems) – which could lead to high temperature, delirium and coma and can cause death – this may occur in between 0.1% - 2% of schizophrenics.
Whereas atypical antipsychotics were developed to overcome these side effects. However, side effects do exist for atypical antipsychotics such as Clozapine thus regular blood tests need to be taken of the patients to test for early signs of agranulocytosis (a rare blood condition where the production of white blood cells is prevented – leads to problems with immunity)

Question 13

Why are there ethical issues using drug therapy for SZ

Answer 13

most profound ethical issue would be consent – e.g. due to the fact that schizophrenia is a psychotic disorder, patients may not be in the right frame of mind to give fully informed consent in taking the drugs and because the drugs do have such severe side effects, one would question the extent of the harm (both physical and mental) and whether the effects of the drugs were reversible especially with side effects such as NMS and tardive dyskinesia