Neurochemical explanation for depression
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Neurochemical explanation for depression
AQA PSYB3 Schizophrenia
What is the dopamine hypothesis?
Dopamine is thought to play a role in cognitive function
Too much dopamine can cause cognitive disturbance
Schizophrenic brains have too many D2 receptors meaning too many impulses are sent in the brain
How do anti psychotic drugs support the neurochemical explanation?
Drugs that block D2 receptors, preventing dopamine from binding and returning it to normal levels and making the neurone fire at a normal rate
Reducing levels of dopamine in the brain reduce schizophrenia symptoms such as hallucinations
What can be concluded from the use of anti psychotic drugs as evidence?
The reduction of symptoms suggests that dopamine plays a part in schizophrenia
These drugs do not work on all patients suggesting dopamine is not the only cause
Treatment fallacy is a possibility
How does Parkinson's disease offer support to the neurochemical explanation?
Parkinson's is a motor functioning inhibiting brain disorder caused by low levels of dopamine in the brain
I dopa, a symptomatic relief drug increases dopamine levels in the brain
Overdose of the drug can lead to schizophrenic symptoms
How do amphetamines offer support to the neurochemical explanation?
When amphetamines are taken in excess, schizophrenic symptoms are often exhibited
Amphetamines increase dopamine levels in the brain
What did Wong et al find?
PET scans were carried out on the brains of schizophrenics
A higher density of dopamine activity was recorded in schizophrenic brains than the control group
The findings haven't been replicated and might not be reliable
How does the neurochemical explanation over emphasise on nature?
It ignores the effect of the environment and other explanations
An interactionist approach is needed to fully explain the disorder
How is the neurochemical explanation deterministic?
It states that people have no free will and are completely controlled by dopamine levels
This leaves sufferers helpless and passive and can lead to forced medication of patients
How is the neurochemical explanation reductionist?
It reduces a complex disorder down to a simple cause, dopamine
This means other factors such as cognitions and environment are ignored when schizophrenia is likely caused by an interaction of factors
How has Dopamine been linked to other illnesses?
It has been linked to other disorders such as OCD and Depression
This suggests that dopamine could be caused by other brain chemicals and dopamine alone is not the cause of schizophrenia
What did Durand and Barlow suggest?
Serotonin plays a bigger part in schizophrenia
Serotonin is a master neurotransmitter that controls other neurochemicals such as dopamine
New drugs such as clozapine that are more effective in reducing symptoms affect serotonin rather than dopamine
How is the neurochemical explanation unfalsifiable and unscientific?
It is difficult to prove or disprove that a single neurotransmitter is causing schizophrenia
The studies into neurotransmitters are flawed and only lead to correlations
Schizophrenia is likely caused by many different chemicals
Why is there a problem with generalisability for the neurochemical explanation?
Only type 1 symptoms can be explained by the dopamine hypotheses
Type 2 cannot be explained
What applications has the neurochemical explanation led to?
Drugs have been developed to treat patients, replacing barbaric practices such as ECT and Psychosurgery
These drugs are less traumatic to take and allow patients to lead a more normal life
How does treatment fallacy affect the explanation?
Just because drugs reducing dopamine levels reduce symptoms, schizophrenia is not necessarily caused by an excess of dopamine
An unknown third variable could be the cause
How can drug treatment be criticised?
Not all patients respond to drug treatment suggesting there are other causes
There are ethical issues with forcing treatment upon patients
What would the interactionist approach suggest?
Schizophrenia is too complex to be caused by a single chemical and is probably the result of many factors