Causes of Schizophrenia Flashcards
Which studies support the Dopamine Hypothesis?
Randrup & Monkvad
Owen
Owen et al.
Comparing the brains of 19 dead schiz vs 19 dead non-schiz, schizophrenics had a higher density of dopamine receptors in certain areas.
Randrup & Monkvad
Injecting rats with amphetamines to raise their dopamine gave them schizophrenia-like symptoms
Which studies support the Genetic Explanation?
Gottesman
Heston
Cardno & Gottesman
Gottesman
Family study into schiz concordance.
6% likelihood if a parent has it
48% if an identical twin has it.
Heston
Comparing rates of schiz in 47 p’s with schiz Mothers and 50 controls. All separated from the biological mothers a few days after birth. 5 p’s with a schiz mother had schiz, half had abnormal behaviours like other MHDs, half had artistic talents and imaginative adaptations. No controls had schiz.
Cardno & Gottesman
Meta-analysis of twin studies comparing MZ & DZ concordance. Higher MZ concordance in every country studied. Heritability measured around 80%.
Which studies support the Cognitive Explanation
McGuire
Gold & Harvey
McGuire
The part of the temporal lobe involved in inner-voice regulation showed lower activity during auditory hallucinations
Gold & Harvey
Showed p’s with schiz scored lower on tests of memory, attention and problem-solving suggesting problems with filtering info.
Chandrasena
In Sri Lanka, there is a higher percentage of schiz Sufferers (21%) who experience catatonia compared to only 5% white British.
Zammit
Analysed historic data about self-reported cannabis use in young Swedish men and found an association between cannabis and schizophrenia.
Susser
found that babies born during the Dutch ‘hunger-winter’ of 1944-45 were 2x as likely to develop schizophrenia.
Dohrenweld
There is a higher incidence rate of schizophrenia in lower-income groups.
What is Frith’s attention hypothesis?
People with schizophrenia have a higher self-awareness so they can’t filter out irrelevant information so they may interpret irrelevant things as personally irrelevant. This can lead to a cognitive overload.
