Antipsychotics by Libby Prosser

About

libbyprosser89 — 2024-02-20 16:15:45 UTC

Antipsychotic drugs block the postsynaptic neuron, which prevents the dopamine from stimulating the receptor sites.

There are several types of antipsychotic medications, however they typically fall into two categories:

Conventional Antipsychotics
Atypical Antipsychotics

Conventional Antipsychotics

libbyprosser89 — 2024-02-20 16:19:11 UTC

They work by affecting neurotransmittion, and block the action of dopamine. They act as a blocking agent for D1 - D5 dopamine receptor sites.

When the presynaptic neuron releases dopamine to the synapse, the postsynaptic neuron is blocked by chlorpromazine which reduces activity in the postsynaptic neuron.

The reduction in dopamine activity in the mesolimbic pathway is thought to be responsible for the decline of positive symptoms such as hallucinations and delusions.

Atypical Antipsychotics

libbyprosser89 — 2024-02-20 16:20:57 UTC

These are known as 'newer' and 'second generation' antipsychotics - they were introduced in the 1990s.

Similarly to conventional antipsychotics, they also work as a blocking agent for dopamine receptor sites. However, it is not known exactly how they work.

How are they different?

libbyprosser89 — 2024-02-20 16:27:29 UTC

Atypical antipsychotics are different to conventional antipsychotics due to the fact that they are received at fewer D2 dopamine receptor sites and more so D1 and D4 receptor sites.
The majority of atypical antipsychotics antagonise the serotonin receptor (5-HT2A) just as they antagonise the D2 dopamine receptor.
There is also a difference in the amount of time that they occupy the D2 receptor sites: Phillip Seeman (2002) proposed the 'fast-off' theory, which explains that atypical antipsychotics fall more loosely to the D2 receptors compares to conventional antipsychotics - this meaning that the effect does not last long enough to produce the side effects seen in conventional antipsychotics e.g. changes in movement of the tongue, mouth, face, etc.
The half life (duration) of the atypical antipsychotics is less than conventional antipsychotics - with atypical antipsychotics the effects fall of within 24 hours, whereas with conventional antipsychotics the fall off is longer than 24 hours.

Effectiveness of Conventional Antipsychotics

libbyprosser89 — 2024-02-20 16:33:08 UTC

Jonathan Cole et al (1964) - conducted a study on the effectiveness of conventional antipsychotics and found that the psychiatry could treat mental disorders in the same way that physical disorders are treated, which is through the use of drugs.
Cole at al - 75% of those given conventional antipsychotic were considered to be much improved compared to the 25% who were given a placebo.

Comparing Conventional and Atypical Antipsychotics

libbyprosser89 — 2024-02-20 19:24:57 UTC

Atypical antipsychotics are typically considered more effective than conventional antipsychotics.
Ravanic et al (2009) compared the effectiveness of clozapine, chlorpromazine and haloperidol in 325 individuals with schizophrenia - found that there was a significant difference in psychometric scores whilst measuring schizophrenic symptoms over 5 years - Discovered that clozapine has fewer effects than haloperidol and chlorpromazine.
The above research suggests that atypical antipsychotics are more effective when treating schizophrenia.

Side Effects

libbyprosser89 — 2024-02-20 19:30:37 UTC

There are many side effects of antipsychotics, these include:

Tardive dyskinesia - a neurological disorder characterised by involuntary movements of the face and the jaw.
Agranulocytosis - a deficiency of granulocytes in the blood which causes increased vulnerability to infection.
Seizure - the physical findings or changes in behaviour that occurs after an episode of abnormal electrical activity in the brain.
Parkinsonianism - tremors and instability

The therapist is left to decide whether or not the treatment is worth the side effects that the patient may suffer.

Chemical Straitjakets

libbyprosser89 — 2024-02-20 19:34:14 UTC

Some psychiatrists argue that antipsychotics are more than chemical straightjakets, and that it keeps people quiet and under control.

Szasz (1960) - using physical treatments for mental disorders is no more sophisticated than believing in demonology, and that the concept of mental illness was simply a way of excluding non conformists from soceity.

Asylums or Care in the Community

libbyprosser89 — 2024-02-20 19:36:41 UTC

'Antipsychotic drugs revolutionised the care of schizophrenia, changing it from an incurable condition which required institutionalisation to one that could be treated in the community, with the potential for independent living and recovery.' - Stephen Lawrie (2011)

The introduction of medication allowed patients to live a normal life in their home environment, which is beneficial for them and for society - it is also cost efficient due to the expense of hospitalisation.

Risk of Violence

libbyprosser89 — 2024-02-20 19:38:42 UTC

Tiihonen et al (2006) - found a 37-fold increase in suicide in patients who stopped taking their medication.
NCISH (2015) - reported that 346 homicides had been committed in England with a history of schizophrenia between 2003 and 2013 - this is 6% of the whole homicide rate.