Biological Treatments

Question 1

What Biological treatment do we look at?

What is the aim?

Answer 1

• Antipsychotic medication (a form of chemotherapy)
• The aim of antipsychotics is to reduce, modulate or stabilise the balance of dopamine and alleviate some of the symptoms of Schizophrenia

Question 2

What are the basic principles of all anti-psychotics?

Answer 2

• These drugs must be taken on a regular basis to keep symptoms under control
• It takes about 7 days before the drug starts to show an effect and symptoms reduce
• initially, positive symptoms are dramatically reduced and slowly some negative symptoms subside

Question 3

What two types of antipsychotic do we look at?

Answer 3

• Typical (e.g. Chlorpromazine)

- Atypical (e.g. Clozapine)

Question 4

Describe Typical Antipsychotics

Answer 4

• Deals with positive symptoms, dopamine antagonist (D2 receptors) reducing dopamine levels
• Hit system - permanent
• By binding to D2 receptors, dopamine transmission is lowered and reduces positive symptoms
• Kapur - approx 60-75% of D2 receptors blocked in mesolimbic pathway

Question 5

What are some side effects from Typical AP’s

Answer 5

Extrapyramidal symptoms. This refers to our motor control which is severely impaired. Examples = Dystonia (uncontrolled and sometimes painful muscle movements) and Tardive Dyskinesia (involuntary movement)

Question 6

Describe Atypical Antipsychotics

Answer 6

• Deal with positive and negative symptoms
• Dopamine modulators that target D2 and 5-HT2 (Serotonin) receptors
• Hit and Run system
• Mesolimbic pathway and Nigrostriatal pathway

Question 7

What are the side effects of Atypical APs

Answer 7

Hypertension, Hypersalivation, Sedation, Weight Loss

Question 8

Describe the action in the Mesolimbic Sensory system

Answer 8

• Involved with emotions and sensations of pleasure. Reducing the hyperactivity of dopamine here should reduce positive symptoms such as delusions
• Using hit and run action AP’s have their effect on dopamine receptors and then quickly leave the receptor site
• This allows the AP to have an effect but then receptors become available for naturally occurring dopamine before the next dose. This action helps avoid some motor side effects

Question 9

Describe the action in the Nigrostriatal sensory pathway

Answer 9

• Has a role in controlling movement, and as such involves dopamine and serotonin (blocking receptors here can lead to motor side effects)
• Presence of serotonin in this pathway antagonises dopamine release, so the APs action is to block serotonin receptors but also stimulate an increase in levels of natural dopamine in dopamine receptors in this pathway and the prefrontal cortex
• so natural dopamine fills receptor sites in other pathways and prevents blocking from APs in this area. This helps tackle negative symptoms and reduce EPS

Question 10

Summarise evaluations of APs as a biological treatment

Answer 10

• Research Support - Davis
• Methodological issues - Ross and Read
• Not effective for everyone - Elesser
• Ethical issues - Consent, Effectiveness and Side Effects
• Effective as part of wider treatment - CBT

Question 11

Summarise Davis

Answer 11

Analysed results of 29 studies of 3519 patients to find out about the effectiveness of antipsychotics. They found relapse in 55% where a placebo was swapped for AP’s compared to 19% relapse for those still taking the AP’s

Question 12

Summarise Ross and Read

Answer 12

Re-analysed the data presented by Davis and suggested that 45% of those using placebo did therefore benefit and not relapse. Also 81% of the AP group would therefore have benefitted from the drug

Question 13

Summarise Elesser

Answer 13

Carried out a longitudinal study and they found AP’s did not help everyone and rarely removed all symptoms. Typical AP’s helped 65% of patients and Atypical helped about 85% of patients