schizophrenia Flashcards
A negative symptom is…
symptom that takes away from the ability to function normally
A positive symptom is…
symptom that adds to normal mental functioning
The two negative symptoms are…
speech poverty and avolition
Avolition is the…
lack of motivation and will to perform tasks/do stuff
The two positive symptoms are…
hallucinations and delusions
co morbidity is…
When a person has two or more disorders at the same time
symptom overlap is…
when two different disorders have a symptom in common/share a symptom.
may lead to incorrect diagnosis
difference between reliability and validity
reliability=consistency of measure
validity-accuracy of measure
State evidence for genetic explanations of schizophrenia
(Gottesman) risk of developing schizophrenia is
48% in twins
9% with a sibling
2% with a relative e.g.uncle
what is the genetic explanation of schizophrenia
If some family members have schizophrenia, then it is more likely they develop schizophrenia due to inheriting the gene alleles for schizophrenia
Schizophrenia is caused by multiple….
gene alleles
e.g .Ripke did a meta analysis of genome wide studies on sch. and found that there are 108 alleles which may increase risk of sch.
Schizophrenia is most likely caused by the gene that codes for….
dopamine
twin study evidence for genetic explanations of schizophrenia
Gottesman
concordance rates for schizophrenia
MZ- 48%
DZ- 17%
adoption study evidence for genetic influence of schizophrenia
Tienari et al.
experimental group-adopted kids whose biological mothers had sch
control group-adopted kids whose biological mothers did not have sch
significantly more kids with sch in experimental group than control group
limitation of adoption studies
Assume that the biological parent has no influence on the child. This is not true because children are paired with adoptive parents with a similar background, living in similar area with biological parent. Ignores potential shared environment between bioparent and child.
what is the dopamine hypothesis?
Sch caused by excess and imbalance of dopamine in areas of the brain
A neural correlate is…
a biological process in the nervous system associated with schizophrenia e.g. dopamine hypothesis
outline 2 features of dopamine hypothesis
1)high levels of D2 receptors on their receiving neurons resulting in more dopamine binding and thus more neurons firing.
4)Low DA in prefrontal cortex leads to high DA in subcortex
original dopamine hypothesis
Hyperdopaminergia- subcortex
HIGH dopamine activity in subcortex e.g. excess dopamine receptors in broca’s area(responsible for speech production) associated with hallucinations and speech poverty
updated dopamine hypothesis
Hypodopaminergia- prefrontal cortex
LOW dopamine affects thinking and decision making(avolition//negative symptoms)
The dopamine hypothesis originates from…
Dopamine releasing drugs produce Schizophrenic symptoms
anti-psychotic drugs like clozapine reduce schizophrenic symptoms
evaluation of the dopamine hypothesis
Correlational research. therefore it is different to determine a causal relationship between dopamine and schizophrenic symptoms. Other factors like other neurotransmitters may influence symptoms of SCH.
(limit) Schizophrenia research is hard deterministic because….
Sch is biologically determined therefore the biological approach to sch states that it has a genetic basis. This makes patients feel discouraged when diagnosed, which may have further detrimental effects on their MH which may worsen their sch symptoms. Cognitive approach(soft deterministic) suggests that mental processes can be altered and manage d via freewill which gives hope to sch patients that they can live a normal life.