1. Chemotherapy

2. Assumption of the Biological Approach
The biological approach is interested in how behaviour is influenced by chemical imbalances in the brain
Chemotherapy tries to correct these imbalances

3. What are these key terms? Type your answer into the box.
Neuron
Synapse
Neurotransmitter
Antagonists
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4. Did you get them right?
Neuron = a nerve cell, which transmits signals through the nervous system. Uses electrical impulses and chemicals.
Synapse = the gap between two neurons, chemicals pass across the gap to stimulate an electrical impulse in the next neuron
Neurotransmitter = chemical substance which transmits messages across a synapse, by fitting into receptor sites and stimulating the next neuron
Antagonists = drugs which reduce the activity of a particular neurotransmitter, usually by blocking the receptor sites

5. Watch the animation
On the next slide you will see an animation to recap how messages are transmitted across the synapse
I’m sure you already know this… let this jog your memory!
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6. Vesicles release neurotransmitter into synaptic cleft
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7. Neurotransmitter binds to receptors & activates them
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8. Enzymes are released to break down the neurotransmitter
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9. Excess neurotransmitter is taken up by the pre-synaptic neurone
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10. Vesicles are replenished with new & reused neurotransmitter
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11. Antipsychotic drugs
These are a form of major tranquilliser used to treat schizophrenia.
Before they were introduced in the 1950s schizophrenia was seen as an untreatable disorder and a diagnosis usually led to a stay in a mental institution.
These drugs were a major breakthrough, where other physiological therapies (including ECT and Insulin shocks) had failed.
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12. Antipsychotic drugs
These are also known as CONVENTIONAL ANTIPSYCHOTICS and they reduce psychotic symptoms
They also produce neurological symptoms
An example is a drug called chlorpromazine
CONVENTIONAL ANTIPSYCHOTICS reduce the positive symptoms of schizophrenia, but don’t affect the negative
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13. Antipsychotic drugs
As an excess of the neurotransmitter dopamine has been linked to the symptoms of schizophrenia, these drugs bind to dopamine receptors and block the build up of dopamine. The post-synaptic neuron is not stimulated and the symptoms are reduced.
It is thought that the parts of the brain linked too schizophrenia (through too much dopamine) are in the cerebral cortex and limbic systems
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16. Antipsychotic drugs
Antipsychotic drugs reduce symptoms such as hallucinations and delusions by sedating the parts of the brain responsible for their occurrence.
Another system linked to dopamine is responsible for motor functions
This system can degenerate, becoming the disorder known as Parkinson’s disease.
Symptoms include tremors, loss of balance, rigidity in muscles, and difficult breathing
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17. Antipsychotic drugs
Unfortunately for schizophrenia sufferers, neuroleptics can produce Parkinson’s disease-like symptoms as a side effect
This is because the drugs interfere with the dopamine in these areas too
Some schizophrenics are reluctant to take these drugs as a result
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18. Antipsychotic drugs
Although these Parkinson’s symptoms tend to be temporary, prolonged use of conventional anti-psychotics can lead to tardive dyskinesia
Look up this disorder – why is it linked to schizophrenia?
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19. Antipsychotic drugs Other side effects include… Windgassen (1992)
50% report sedation
18% have poor concentration
16% suffer a reduction in salivation
16% get blurred vision
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20. Antipsychotic drugs However, there is a silver lining!!
Clozapine is a drug that has been recently introduced
It produces fewer side effects than other drugs
This has also improved both the positive and negative symptoms of schizophrenia
30-50% improve whilst on the drug
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21. Clozapine
However, 2% develop a potentially fatal blood disorder and so they need to be monitored
Clozapine is also more expensive than other drugs
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22. Antidepressant Drugs
Depression is a mood disorder where the patient feels low (don’t worry – we go into more detail later in the course)
This low feeling is connected to a low level of the neurotransmitter serotonin in the synapse between nerve cells.
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23. Antidepressant Drugs – How they Work
Reducing the rate of reabsorption
Blocking the enzyme that breaks down the neurotransmitter
Either action would increase the amount of neurotransmitter available to transmit impulses to neighbouring cells.
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24. Antidepressant Drugs – How they Work
Selective Serotonin Reuptake Inhibitors
SSRIs - Eg PROZAC
These drugs stop Serotonin being reabsorbed back into nerve cells.
Because it is there longer it can pass on more impulses.
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25. Antianxiety drugs
Anxiety and stress are commonly treated by Benzodiazepines (BZs) eg Valium.
They work on the Central Nervous System
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26. Antianxiety Drugs – How BZs Work
Increase the activity of GABA (a neurotransmitter) which naturally reduces anxiety.
GABA locks on to receptor cells and opens up a channel allowing chloride ions into the neuron, making it harder to be stimulated and slowing down its activity.
The result is a feeling of relaxation
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27. Antianxiety Drugs – How Beta-Blockers(BBs) Work
Reduce activity of adrenaline and noradrenaline (hormones)
Bind to receptors on target organs (eg heart) making them harder to stimulate and so reducing arousal – lower blood pressure and less anxiety
Used by snooker players and musicians
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28. Effectiveness of Chemotherapy
Popular with patients – easy to use
Side-effects
Antipsychotics – tardive dyskinesia
Antidepressants – increased suicide risk
Effective in reducing symptoms – compared to placebos
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