schizophrenia p3 Flashcards
(89 cards)
What do family studies show about risk of developing schiz?
family studies have shown risk of schiz incrseaese in line with genetic similarity relative ot the disorder.
a large scale family study found that has an aunt with shciz has a 2% chnace at developing it,
and
9% if individual has sibling with it and
48% if an identical twin. which shows a positive correltion betweenthe two.
define schiz?
is a serious mental disorder in which contact with reality is impaired. or distorted.
how do we diagnose a disorder?
to do this we need to distingiush one disorder from another and identify a cluster of symptoms that occur togther and classify it itno one disorder.
what is the DSM5 and what does it stand for// and how does it diagnose schiz?
diagnostic statistical manual and need one positive symptom of schiz to be present
what is the ICD-10 and how does it diagnose schiz?
intenational classification of disease version 10 and diagnosis schiz when two or more negative symptoms are present.
define what positive symptoms are? and give 2 examples?
positive symptoms are addtional experinces of ordinary life/exisistence.
hallucinations are unsual sensory experineces that are related to events in enviroment or dont at all such as seeing a face distorted ir hearing voices that criticism.
delusions: are irational beliefs about somehting or someone
define what negative symptoms are and give examples 2?
negative symptoms of schiz involve a loss of usual abilities and everday life experineces and includes speech poverty and avolition.
speech poverty is lack of fluency or changing patterns of speech such as changing the topic mid sentence.
avolition: lack of motivation to do a daily task and can be classified into lack of hygiene or grooming lack of persistence in work or lack of energy.
Why is one strength of schiz good reliablty?
this is becase relaibty means consistency and a diagnosis is sadi to be reliable when different diagnosing clinicians reach the same diagnosis on two different occsions (test rest reliability)
and iter rate relialbilty is when different clinicains diagnose same individual fro same diagnosis
prior to the the DSM5 there was a low reliability of schiz , but now has improved as the reliability for diagnosis for schiz in 180 indivuals using dsm5 reached 9.7+for inter rater and 9.2+ fro test retest reliability.
so this is a stregnth because we can be sure that diagnosis of schic can be consistently applied.
why is low validity a - for diagnosis of shciz?
this is becassue diganosis fro schiz is low validity.
one way of assessing validity is crietrion validity and a researcher had 2 psychiatrists independantly assess same 100 clients using ICD10 and DSM5 and found 68 diagnosed with schiz under IDC10 and only 39 with DSM-5.
suggestng that schiz maybe be over or under diagnosed and criterion of validity is low and cannot accurateky diagnose schiz.
What is a conterpoint for ow validity of schiz diagnosis?
However in the study above it was reported that there was a excellent agreement betwen psychiatrists when they used 2 measures diagnose shciz derived from DSM. meaning that criterion validity is good when a single diagnostic system is used.
why is symptoms overlap a - of diagnosing schiz?
this is because they can overlap with other condtions such as bipolar disorder.
an example is that both disorders involve positive symptoms and negative syptoms.
and in terms of classification is maybe that they are two different disorders but variation of a single conditon and hard to distinguish schiz from bipolar disorder..
this is a limitation because symptoms overalp eans that shciz may not exist as single condition even if it hard to diagnose. so both classification and diagnosis is flawed.
why is gender bias a limitation for diagnosiing schz?
one limitation of schiz diagnosis is gender bias. this iarises fro the fact that since the 1980 men have been diagnosed with schiz than women. This maybe due to women being less vulanrable than men maybe becasue of genetic factors. But cotton et al showed that women are nderdiagnosed becasue they have closer relatioships so get support leading to women functioning better than men but still doesnt get detected..
therfore this is a - because underdiagnosis means that women may not recive treatment and services that help them more.
What are candidate genes?
a number of faulty genes involve in the risk of dveelping schiz.
How are candidate genes linked with schiz?
A number of genes are invloved so schiz is polygenic and are the genes that code for neurotransmitter code for dopamine
what did one study find about genomes and schiz?
in a large study a researcher combined large studies from wide genome studies and looked at whole human genome opposed to particular genes and found 108 seperate genetic variations were associated with isk of schiz.
this was found when 37000 genome of people with schiz was compared to 113000 controls
what is /describe the role of mutation?
schiz can have a genetic origin in absence of a famiy histroy of dirsorder through mutations,
and cn be due to chnages in DNA parental from a virus poisin or infection.
evdidince come from positve correlations from paternal age and incrseased of sperm mutation.
0.7% fro father under 25 and 2% fro over 50.
what affect does dopamin have on brain/ its role and on neurons?
has excitatory effect on brain and asscoaited with levels of pleasure
Describe what the orginal DA hypotheiss states?
oG hypothesis is based on drugs that used to treat schiz /antipsychotics caused symptoms similiar to parkinsons disease associated with low dopamine levels
so schiz maybe caused by high level of dopamine in subcortical areas of the brain.
what is an example of the OG dopamine hyptheis?
Excess of DA receptors in pathways subcortex to brocas area can be repsosible for speech poverty or auditry hallucinations.
What does the updates version of DA hyopthsi explain shcz?
Abnormally low level of DA in the brain cortex especially in prefrontal cortex. respsonible for thinking could explain cognitve problems such as speech poverty.
Why does the new hypothis sifr schiz show that high and low levels of DA cause schiz?
because low levels in cortcial area can lead to high level in subcortical areas
so both high and low levels of DA an cause schiz.
how can this new hypothesis be applied in explaining schiz on agenetic basis?
because both early experiences and gentic varations can make people more sensitive to cortical low DA and hence high DA in subcortex.
What is one strength for evidince for dopamine?
one + is that there is support that DA is involved in schiz.
This is becasue amphetimines increase DA and worsen sytpoms in people without schizprenia.
also anipsychtic drugs reduce DA activity and can also reduce severty of symptoms. and some candidate genes can act on prodcution of DA receptors.
Why is role of glutamate a - for bio exp for schiz?
becasue there is a central role of gltamate in schiz.
eveidince come from post mortem and live scanning techniques that hsow raised levels of NTRA glutamtae in several region of the brain with schiz.
and several candidate genes for schiz are thogh to be involved in glutamate productoion.
suggessting that glutamate plays a role as a NTRA fro schiz.