Biological explanation of schizophrenia Flashcards
What is the genetic explanation of schizophrenia?
Schizophrenia is an inherited disorder that runs in families, with faulty genes being passed down from generation to generation.
What did Gottesman (1991) find in his summary of twin studies regarding schizophrenia?
Gottesman found a concordance rate of 48% for MZ (identical) twins compared to 17% for DZ (non-identical) twins. This suggests that genetics plays a role in the similarity of schizophrenia in MZ twins.
What were the findings of Gottesman (1991) in his family studies of schizophrenia?
Gottesman found a 46% chance of developing schizophrenia if both parents had the disorder, a 16% chance if one parent had it, and a 1% chance if no relatives had it.
What did Tiernari’s adoption study (1991) reveal about the genetic influence on schizophrenia?
Tiernari found that 10.3% of children with schizophrenic mothers developed the disorder compared to just 1.1% of children without schizophrenic mothers, even though the children were raised in different environments. This suggests a genetic component to schizophrenia.
What does Tiernari’s adoption study suggest about the influence of genetics versus environment on schizophrenia?
It suggests that the genetic component of schizophrenia plays a significant role, as children with schizophrenic mothers were more likely to develop the disorder, regardless of being raised in different environments.
What are candidate genes in the context of schizophrenia?
Candidate genes are genes associated with an increased risk of schizophrenia. Schizophrenia is polygenic, meaning multiple genes work together to increase susceptibility.
What did Ripke et al. (2014) find in their study of schizophrenia?
Ripke et al. identified 108 genetic variations associated with schizophrenia risk, including genes related to neurotransmitter functioning (e.g., dopamine).
What does it mean when schizophrenia is described as “aetiologically heterogeneous”?
It means that schizophrenia can be caused by different combinations of genetic and environmental factors, and there isn’t one single cause for the disorder.
What does polygenic mean in the context of schizophrenia?
The polygenic nature of schizophrenia means that multiple genes contribute to the disorder, and different combinations of these genes can result in various forms of schizophrenia (e.g., paranoid, catatonic, residual).
Fill in the gaps: ________ levels of dopamine are linked with schizophrenia
High
Fill in the gaps: ___________dopaminergia in the ___________________ means high levels of dopamine
Hyperdopaminergia in the subcortex means high levels of dopamine
What is hyperdopaminergia in the subcortex, and how does it relate to schizophrenia?
Hyperdopaminergia refers to high levels of dopamine activity in the subcortex. It is thought that excess dopamine receptors in areas like Broca’s area (responsible for speech) may contribute to symptoms such as poverty of speech and auditory hallucinations.
Fill in the gaps: ___________dopaminergia in the ___________________ means low levels of dopamine
Hypodopaminergia in the pre-frontal cortex means low levels of dopamine
What is hypodopaminergia in the prefrontal cortex, and how is it linked to schizophrenia?
Hypodopaminergia refers to low levels of dopamine in the prefrontal cortex, an area responsible for decision-making. It is associated with the negative symptoms of schizophrenia, such as lack of motivation and impaired cognitive function.
What type of symptoms are linked with hyperdopaminergia?
Positive
What type of symptoms are linked with hypodopaminergia?
Negative
What are neural correlates?
Neural correlates are measurements of the structure or function of the brain that correlate with an experience, in this case, schizophrenia.
What role does the ventral striatum play in schizophrenia? What symptom is it linked with?
The ventral striatum is involved in the anticipation of reward, and abnormalities in this area may contribute to the negative symptom of avolition (low motivation).
What did Juckel et al. (2006) find about the ventral striatum in patients with schizophrenia?
Juckel et al. found that patients with schizophrenia had lower activity levels in the ventral striatum compared to controls.
What brain areas were found to have reduced activity in patients with auditory hallucinations?
The superior temporal gyrus and anterior cingulate gyrus showed reduced activity in patients with auditory hallucinations.
What’s a strength of the genetic explanation of schizophrenia?
Lots of research support, e.g. Gottesman, Tiernari, Ripke etc. There is therefore overwhelming evidence for the idea that genetic factors make some people much more vulnerable to developing schizophrenia than others.
What is a strength of the dopamine hypothesis of schizophrenia?
- Research support shows that dopamine agonists (drugs that increase dopamine levels) can cause schizophrenic symptoms and dopamine antagonists (drugs that decrease dopamine levels) decrease schizophrenic symptoms in patients with schizophrenia.
- Practical applications - the dopamine hypothesis lead to the creation of typical and a-typical anti-psychotics.
What is a weakness of the neural correlates explanation of schizphrenia?
There is a correlation-causation problem. It is unclear whether the abnormality in an area of the brain caused schizophrenia, or if schizophrenia caused the abnormality in that area of the brain.
What is a weakness of the biological explanation of schizophrenia?
Reductionism - it fails to take into account any psychological explanations, for example the cognitive explanation or the family dysfunction explanation.
