Schizophrenia Flashcards
define schizophrenia
a psychotic disorder characterised by severe symptoms in areas of judgement, emotions, perception and behaviour
what 3 things are needed for a schizophrenia diagnosis (DSM-4)
characteristic schizophrenia symptoms, social/occupational dysfunction and duration
what are the conditions of characteristic schizophrenia symptoms (DSM-4)
2 or more symptoms, present for a significant time in a 1-month period
what are the conditions of social/occupational dysfunction (DSM-4)
below prior level in one or more major areas of functioning such as work, interpersonal relations or self care
what are the conditions of duration (DSM-4)
at least 6 months, in which symptoms must persist for at least 1 month
define delusions
incorrect beliefs due to distortions or exaggerations of reasoning and/or misinterpretation of experiences
define hallucinations
distortions or exaggerations of perception in the senses
what types of delusions are there
paranoid delusions (delusions of persecution), delusions of grandeur, delusions of reference- believing things in the environment are related to you, somatic delusions- false beliefs about the body
name the positive symptoms of schizophrenia
delusions, hallucinations, disorganised speech/thinking
name the negative symptoms of schizophrenia
alogia, affective flattening, avolition
explain validity in schizophrenia diagnosis
predictive validity- if diagnosis leads to successful treatment the diagnosis is valid
descriptive validity- patients with schizophrenia should differ in symptoms from patients with other disorders
explain reliability in schizophrenia diagnosis
test retest reliability- same clinician makes same diagnosis from same information on separate occasions
inter rater reliability- different clinicians make identical, independent diagnoses of the same patient
what did rosenhan study
reliability and validity in diagnosis of schizophrenia
describe rosenhan’s study
8 pseudo patients called a hospital with symptoms of hearing a same-sex voice saying ‘empty’, ‘hollow’ and ‘thud, once admitted patients acted and spoke normally and didn’t mention the voices, pseudo patients did everything they were told but didn’t take medication, they made notes
what did rosenhan’s study find
7 out of 8 pseudo patients were admitted with a diagnosis of schizophrenia and discharged with schizophrenia in remission, they stayed an average of 19 days (range of 7-52 days), they were never detected as being fake
describe rosenhan’s second experiment
staff at a hospital were told to detect any pseudo patients that rosenhan’s had sent, rating them on a scale of 10 of how likely they were to be a fake (1/2- high confidence), however none were sent
what did rosenhan’s second experiment find
after 3 months one staff member highly confidently rated 41 patients as pseudo patients, 23 patients were rated highly confident by at least 1 psychiatrist, 19 by a psychiatrist and another member of staff
classification of schizophrenia peel 1
p- criticism of reliability, cultural variations
ev- luhmann et al, 60 adults with sz (20 each- Ghana, India, US), African/Indian ppts reported positive experiences with playful voices, not one US ppt did- more likely to report violent/hateful voices
ex- classification of sz is changeable dependent on culture, more socially acceptable in Africa/India where hallucinations are viewed as positive, so diagnosis rates are lower, less socially acceptable in US so diagnosis rates are higher, low reliability- no cultural agreement of what sz is
l- socially sensitive research, diagnosing other cultures by western standards, are they really experiencing sz, is it more of a spiritual experience in those cultures, do they need a diagnosis
classification of schizophrenia peel 2
p- criticism of reliability, poor inter-rater reliability
ev- chenioux et al, 2 psychiatrists diagnosed 100 patients using DSM and ICD, one diagnosed 26 by DSM and 44 by ICD, the other diagnosed 13 by DSM and 24 by ICD
ex- no consistency in how to diagnose sz, poor reliability between psychologists and classification systems, a clear diagnosis is difficult
l- is sz a true disorder if its so difficult to diagnose, hard to distinguish between symptoms of other disorders, definition is constantly changing, more of a spectrum
classification of schizophrenia peel 3
p- criticism of validity, gender bias
ev- loring and powell, 290 randomly selected male and female psychiatrists, 56% gave diagnosis of sz when case was described as ‘male’, 20% for ‘female’, women more likely to receive depression diagnosis
ex- women underdiagnosed, ability to mask emotions and cope in work/relationships so don’t hit criteria for sz, low validity in diagnosis
l- biased diagnosis in male psychiatrists, gender bias not as prominent in female psychiatrists, can see through masking in female patients
classification of schizophrenia peel 4
p- criticism of validity, co-morbidity, symptom overlap
ev- most people with sz tend to be diagnosed with another: 50% with depression, 47% lifetime substance abuse, 12% fulfil OCD criteria
ex- symptom overlap could lead to misdiagnosis, low validity, when co-morbidity can be difficult to treat disorders appropriately when different treatments are needed, are conditions seperate or interactionist
l- real life implications, if not receiving correct treatment, will not get better, implications for the economy, more individualistic approach needed looking at specific individuals’ symptoms
what explanations are included in the biological explanation of sz
genetic, dopamine hypothesis, neurophysiological (neural correlates)
what 3 key terms are needed in the genetic explanation about sz
polygenic- not caused by one gene but several interacting
aetiologically heterogeneous- the disorder has different causes
candidate gene- any genes thought to cause a disease or disorder
what did ripke find
meta-analysis of 37,000 patients and 113,000 controls, 108 separate genetic variations associated with increased risk of sz, genes coded for function of neurotransmitters like dopamine
what did gottesman research
family study, secondary data (danish civil registration, danish psychiatric central register), of approx 3 million danish people, diagnosis of sz by ICD, 4 groups: 1- both parents with sz, 2- one parent with sz, 3-neither parent, 4- no data (3/4 controls)
what did gottesman find
risk of sz increases with % of DNA shared, risk is highest in mz twins (48%) followed by dz twins (17%), parents 6%
genetic explanation of sz peel 1
p- research support from family study
ev- gottesman, meta analysis, denmark, 3 million people, 48% concordance mz twins, 17% dz, 6% parents
ex- increased risk of sz with more genes shared, must be genetic component
l- not 100% concordance in mz twins who share 100% DNA, must be other causes, environment, SLT, sharing similar env to parents
genetic explanation of sz peel 2
p- research support from adoption study
ev- heston, 30 sz mothers and 33 non sz mothers, children put immediately into foster care, 16.67% concordance sz in biological, 0% in adopted
ex- rates of sz higher in mothers with sz, 50% DNA shared, rates lower in mothers without sz, must be some genetic component
l- better than gottesman, no env influence (adopted from birth), but would expect higher concordance if genetics was cause, 50% DNA is shared but concordance is only 16.67%
genetic explanation of sz pee (3)
p- diathesis stress may best explain sz
ev- tienari,145 children in genetic risk group with at least one bio parent with sz, control group had no genetic risk, family dysfunction only triggered sz if the child had a genetic risk
ex- genetic vulnerability combined with an env trigger = sz, interactionism, high risk of developing sz genetically + stress from high criticism and conflict
what are the 4 dopamine explanations for sz
hyperdopaminergia in broca’s, mesolimbic area, hypodopaminergia in mesocortical area, prefrontal cortex
explain the influence of hyperdopaminergia in broca’s area on sz
responsible for speech production, excess in dopamine -> auditory hallucinations
explain the influence of hyperdopaminergia in mesolimbic area on sz
associated with positive symptoms, limbic system associated with controlling emotions like fear -> implications in delusions of persecution, responding to sensory info -> sensory hallucinations
explain the influence of hypodopaminergia in mesocortical area on sz
responsible for motivation, decision making, goal oriented behaviour -> symptoms like avolition
explain the influence of hypodopaminergia in prefrontal cortex on sz
responsible for decision making, motivation -> negative symptoms like avolition
dopamine hypothesis peeleel
p- research support
ev- antipsychotic drugs which reduce activity of dopamine reduce psychotic symptoms
ex- reduction in dopamine leads to reduction in psychotic symptoms, dopamine must have implications in positive symptoms (hallucinations/delusions)
l- not only dopamine causes positive symptoms, only 1/3 of psychotic drugs alleviate hallucinations, some people have symptoms when dopamine levels are normal, must be another factor too
ev- likely dopamine is involved but other neurotransmitters too, glutamate may be more influential, current research focus
ex- dopamine hypothesis alone is reductionist, dopamine not only cause, likely multiple neurotransmitters
l- may not even be purely biological, diathesis stress, epigenetics, childhood trauma may switch on/off genes, in this case diathesis is trauma which causes the biological stressor of high or low levels of dopamine
define neural correlates
measurements of the structure/function of the brain that correlate with an experience (schizophrenia)
neural explanation- mesolimbic system
amygdala, responsible for emotion -> affective flattening
hippocampus, fear and stress response -> delusions
neural explanation- mesocortical system
deficits in nerve connections between ml + mc (prefrontal cortex), reasoning, speech production -> alogia, delusions
dopamine released in basal ganglia indirectly affects processing of info in pfc