schizophrenia Flashcards
introduction to schizophrenia - diagnosis/classification
diagnosis made by identifying/deciding what disord pers has
2 maj sympt for classification of ment disord : DSM-5 (world health organis)/ICD-10
differ slightly for classific of ment disord, ex. DSM-5 req +ve sympt for diag b ICD 2/+re -ve sympt sufficient
both have dropped subty bec e inconsistent
intro to schizophrenia - +ve symptoms
additional experi beyond those of ordinary existence
hallucinations ; unusual sensory experi, some relat to environmental events, may hear/smell things
delusions; irrational beliefs, makes pers beh in ways that make sense to them b not oths
intro to schizophrenia - negative symptoms
loss of unusual abilities/experiences
speech poverty; reduction in amou/quality of speech accomp w delay in verbal resp in convo
avolition; difficulty to begin/keep up w goal directed act
poor hygiene, lack persistence in work/education and lack energy
evaluation - good reliability (osario et al) ; intro to schizophrenia
osario et al; excellent reliability in 180 indiv using dsm-5 on 2 occas, test retest/inter rater reliability
interviewed pairs achieved IRR of +0.97 and TRR of +0.92
TF: reasonably sure diag of schz consistently applied
evaluation - low validity (cheniaux et al); diag/classif
limit
cheniaux et al; criterion validity used to assess validity of schz
2 psychiat indep assess 100 clients using dsm/icd
fou 68 diag in icd / 39 w dsm
TF: sugg schz over diag/under diag in each one wh sugg criterion validity low
evaluation - co morbidity (buckley); intro to schz
limit
if cond occur tg a lot of time this calls into q the validity of their diag/classif bec might be single cond
where 2 cond freq diag tg
TF: qs validity of classifying 2 disorders sep
evaluation - gender bias in diag; intro to schz
limit
men diag +re than wom bec wom less vulner than men due to genetic factors
how +re likely wom underdiag bec they closer relationships w peop and supp so wom funct bett w schz than men
TF: underdiag is gender bias /wom x get treatment that will benefit them
evaluation - culture bias in diag; intro to schz
limit
some sympt ie hearing voices have diff meanings in diff cult
ex. haiti, hearing voices r communic fr ancestors
also british caribbean peop 9x +re like to receive diag than british peop
there’s cult bias of clients by psychiat fr diff cult backgr
TF: means brit A-C may be discrim against in cult biased diag sys
biological explanations of schz - family studies
risk of schz increases w genetic similarity to relative w disorder
gottesmans family study; some1 w sibling has 9% chance developing schz and 48% if identical twin
general populat is 1%
family memb share aspects for their environ/genes
biological explanations of schz - candidate genes
schz is polygenic , most likely genes coding 4 neurotransmitters ie. dopamine
ripke et al; combin all prev data fr genome wide study of schz
genetic make up of 37000 peop w diag of schz compar to 113000 controls, fou 108 sep genetic variations assoc w slightly increased schz
diff stud identif diff candidate genes so appears schz is aetiologically heterogeneous
biological explanations of schz - role of mutation
schz can have genetic origin even in absence of family history of disorder
mutation in parents dna wh caused by radiation/poison/viral infection
evid for mutation fr +ve correlation b/w parental age and schz risk
increasing fr 0.7% w fath under 25 to over 2% in fath 50+
biological explanations of schz - og dopamine hypoth
bas on discov that drugs used to treat schz caused symp simi to those in peop w parkinson’s disease
schz may be res of high lev DA in subcortical brain areas (hyperdopaminergia)
ex. excess DA receptors in pathways fr subcortex to broca’s area may expl specific schz symp ie. speech poverty
biological explanations of schz - updated versions of dopamine hypoth
davis et al; proposed cortical hypodopaminergia wh is low lev DA in brains cortex
low DA in prefrontal cortex cou expl cog prob
sugg that cortical hypodopaminergia leads to subcortical hyperdopaminergia, both high/low lev DA in diff regions of brain part of updated version
also both genetic variations/early experi of stress make some peop +re sensitive to cortical hypodopaminergia hence subcortical hyperdopaminergia
evaluation - research support (teinari/hilker); bio expla 4 schz
strength
fami stud show risk increases w genetic simi w schz fami memb
tienari et al: adoption stud, fou biolog child of parents w schz at heightened risk even if grow up w adopted fami
hilker et al; twin stud, show concordance rates of 33% identical twins and 7% non identical
TF: shows some peop +re vulnerable to schz as res of genetic make up
evaluation - environmental factors; bio expla 4 schz
limit
clear evid environment fact increase risk for schz
trauma leads to adult ment health prob b evid now partic for schz
morkved et al; 67% peop w schz /related psychotic disorders report at least 1 childh trauma compar to 38% of matched grp w non psychotic ment health issues
TF: means genetic fact alone x prov complete expla 4 schz
evaluation - evid 4 dopamine ; bio expla 4 schz
strength
amphetamines incr da /worsen symp in peop w schz and induces symp in peop w/o
antipsychotics decr da activity /reduce symp intensity
some candidate genes act on production of da/da receptors
TF: strongly sugg da involv in symp schz
evaluation - glutamate; bio expla 4 schz
limit
post mortem/live scanning stud consist fou raised lev og glutamate in sev schz brain regions
sev candidate genes for schz believed involv in glutamate production/processing
TF: means usually strong case can be made for oth neurotransmitters
psychological expla for schz - schizophrenogenic mother
reichmann; noted many of her patients w schz describ partic ty of parent
characterised by cold, uncaring, controlling, rejecting
creates tension/secrecy wh leads to atmosphere of distrust and developm of paro thoughts wh beco delusions
psychological expl 4 schz - double bind theory
bateson et al; emphasis role of communication style w/n fami
developing child regularly finds themselves trapped in situs where they fear doing wrong thing b receive mix messages abo what is wrong thing
when ‘get it wrong’ child punished by withdrawal of love so think world is confusing/dangerous
reflected in symp like disorganised thinking/paro delusions
he makes clear that it’s just a risk factor
psychological expla 4 schz - expressed emotion
lev emot express. towards pers w schz by their carers
contain; verb criticism of pers, hostility towards pers, emot over involvement in pers life inclu needless self sacrifice
high lev EE directed towards indiv r serious source of stress for them
primarily expla 4 relapse in peop w schz how. also sugg that it may be source of stress that can trigg onset of schz in pers already vulnerable
psychological expla 4 schz (cog expla) - dysfunctional thinking
schz characterised by disruption to normal thought processing
reduc thought process in ventral striatum assoc w -ve symp
reduc process info in temporal/cingulate gyro assoc w halluc
this lower than usual lev of info proc sugg cog like 2 be impaired
psychological expla 4 schz - metarepresentation dysfuntion (cog expla)
frith et al; metarep, cog abil to reflect on thoughts/beh wh allows insight in2 own intentions/goals and allows us to interpret actions of oths
dysfunct in metarep wou disrupt abil to recog own act/thoughts as being carried out by ourselves than some1 else
expla halluc of hearing voices /delusions like thought insertion