Schizophrenia Flashcards
What is schizophrenia?
Severe mental illness where contact with reality and insight are impaired.
What is used to diagnose sz?
DSM-5
What are positive symptoms?
Additional symptoms beyond those of ordinary existence eg. hallucinations and delusions.
What are negative symptoms?
Loss of usual abilities and experiences eg. speech poverty and avolition.
What is a strength of the diagnosis and and classification?
Reliability, inter rater and test retest. Osorio et al 180 individuals, inter rater +97, test retest +92. Reasonably consistently applied.
What are limitations of the diagnosis and classification?
Low validity -, criterion validity, Cheniaux et al 2 psychiatrists same 100 clients, 68 ICD diagnosed, 39 DSM. So under or over diagnosed.
Comorbidity - sz commonly diagnosed with other conditions eg. about half depressed/substance abuse. May not exist as distinct condition.
State some correlations Gottesman suggested?
mz twins - 48%
siblings - 9%
general population - 1%
What are candidate genes?
Genes associated with higher risks of sz developing
What does polygenic mean?
Number of different genes associated with sz
What did Ripke find about genes?
108 genes involved in sz risk
What does aetiologically heterogenous mean?
Different combinations of factors can lead to the condition.
What is another genetic factor?
Mutations due to radiation, poison or infection
What did the original dopamine hypothesis suggest?
High levels of dopamine in subcortical areas of brain. Can be responsible for speech poverty due to brocas area having excess DA receptors.
What did the updated dopamine hypothesis suggest?
David et al - low DA in brains cortex. eg. low in prefrontal linked to negative symptoms. also looks at origins of abnormal DA function
evaluate genetic explanations
strength - strong evidence, family studies eg gottesman show risk increases with genetic similarity. Adoption studies eg Tienari et al bio children of sz parents heightened risk. Twin study Hilker et al concordance rate 33% mz, 7% dz.
limitation - clear evidence for environment. bio environmental eg birth complications, and thc smoking.. Also psych environmental eg trauma. Morkved et al - 67% sz at least one childhood trauma. genetic factors alone not enough
evaluate neural correlates
strength - support for DA involvement, amphetamines increase DA and worsen symptoms and induce symptoms in people without. antipsychotics reduce DA levels and reduce symptoms.
limitation - glutamate role, post mortem and live scanning studies found raised levels of glutamate. several candidate genes linked to glutamate production.
explain family dysfunction
schizophrenic mother -
Fromm Reichmann, cold rejecting and controlling. leads to paranoid delusions and sz.
double bind theory -
Bateson et al, mixed messages of right and wrong, lead to disorganised thinking and paranoid delusions.
EE - verbal criticism, hostility and emotional overinvolvement. can explain relapsing and triggering individual vulnerable of sz