Biological Explanations for SZ Flashcards
Genetics Explanation
Suggests that SZ is inherited through genes passed down in families
Gottesman (1991) family study
Explored concordance rates for SZ in families expressed on a graph
Gottesman family study findings
6% parents, 9% siblings, 17% fraternal twins, and 48% identical twins
Cardno et al. (1999) twin study findings
40% concordance rate in MZ twins compared to 5.3% in DZ twins
Heston (1966) adoption study
47 children of SZ mothers who were adopted, and a control 47 children raised by their non-SZ mothers.
10% children with SZ mothers developed SZ, and none of the control group did.
Criticism of genetics research
Inconsistent findings/contradictory research
Diathesis-Stress Model
Suggests that there must be both a predisposition (diathesis) and stressor, such as smoking cannibis or having a child etc.
Initial Dopamine Hypothesis
Suggests that those with SZ are hyperdopaminergic
Falkai et al. (1988)
Autopsies of people with SZ found that they had a large amount of DA receptors, excess in left amygdala
Revised dopamine hypothesis
More focus on the limbic system, subcortical areas involved in behaviours such as emotion, memory, and arousal
Mesolimbic Pathway
Too much dopamine transferring from the ventral tegmental area (VTA) to the nucleus accumbens (NA), which causes overactivity leading to positive symptoms (hyperdopaminergia)
Mesocortical Pathway
Too little dopamine transferred from the ventral tegmental area to the frontal lobe, causing deficits in activity and therefore negative symptoms
How does the Brocca’s Area link to negative symptoms?
Responsible for speech and language - alogia - underactivity results in lack of content
How does the frontal lobe link to negative symptoms?
Responsible for emotions (flat affect), decision-making, logic, pleasure (anhedonia), and personality (asociality), (avolition)
