Biological explanations of schizophrenia Flashcards
Dopamine hypothesis
- chemical cause for schizophrenia and it is thought that it may be due to excess dopamine
- the brain of a schizophrenic person produces more dopamine than a normal brain - brain of a schizophrenic is more sensitive due to dopamine
- certain D2 receptors are known to play a key role in the development of schizophrenia and lowering dopamine activity helps remove some of the symptoms of schizophrenia
Evidence for the dopamine hypothesis
Falkai et al
- autopsies have found that people with schizophrenia have a larger than usual number of dopamine receptors
- found increase of dopamine receptors in brain structures and receptor density and concluded that dopamine production is abnormal for schizophrenia compared to normal controls
Parkinsons disease
those who suffer from parkinsons were given the drug L-dopa
-L-dopa raises dopamine activity in the brain
- reducing parkinson’s symptoms but parents began to develop schizophrenic symptoms
Role of drugs
LSD the effects of dopamine in the brain
- large quantities lead to delusions and hallucinations
- characteristics associated with schizophrenia
- if drugs taken by schizophrenic patients then the patient will get worse
PET scans
- Lindstroem et al (1999)
L dopa was administered to 10 patients with schizophrenia and 10 with no diagnosis
L dopa stayed in the brain of the schizophrenic patients for longer - those with schizophrenia have seen to have more dopamine receptors
Revised dopamine hypothesis
- dopamine hypothesis was seen as being too simple because using drugs to reduce the levels of dopamine had the little effect n those who suffered mainly with negative symptoms
Dopamine receptors are of particular interests, mainly found in the subcortical regions, in the limbic system
- mean the limbic system became the main focus of the hypothesis in recent years
- limbic system has a range of functions including emotion, memory formation and arousal
Describe one biological explanation of schizophrenia
1) original dopamine hypothesis - explain what it is
2) evidence for dopamine hypothesis - falkai et al, Role of drugs, parkinson’s, PET scans
3) revised dopamine hypothesis
Evaluation
- can be difficult to establish a cause and effect
- may not be excess dopamine that causes schizophrenia but schizophrenia itself causes the dopamine imbalances
- dopamine imbalance may just be a symptom of schizophrenia rather than the cause — evidence is correlational
- no research to establish which come first, this can cause doubt on the validity of the hypothesis
practical applications
- allows sufferers to reduce the amount of positive symptoms and to manage their condition to have a certain standard of life
- some may say it is useful as a form of social control — lowers the dangers to society and managing people who do not conform to social norms
- traditionally drug therapy has no effect on symptoms
CBT may be more appropriate when it comes to managing the behaviour of patients who do not respond to medication
- suggest biology may not be the only factor involved
Evaluation 2
Reductionist?
- it is reductionist as it is breaking down the explanation for schizophrenia to be a biological one
- seen as a scientific way to clinically investigate disorders in an effort to establish a cause for schizophrenic behaviour
- ignores all other possible explanations
Deterministic?
- proposes that schizophrenia is determined by internal factors that are out of our control
- biochemical factors are not within our control — takes the blame away from the sufferer or the sufferers family as being the cause for their disorder
- assumes there is little hope for the patient to change
Conclusion
evidence presented suggests not all cases of schizophrenia can be explained by biology
- biological explanation may not be as influential in the onset of the disorder as it claims to be
- indicates other factors should be considered if we are to continue to gain fuller understanding of this disorder
Sample question : evaluate on biological explanation of Sz
3 paragraphs
- 1 strength 2 weakness
PEE structure
finish with conclusion
