paper 2-schziophrenia Flashcards
what is the prevalence of SZ
characterised by split between schizophrenics mind and reality
1% of population likely to get it
what age are people typically diagnosed
late teens, early 20s
which gender is diagnosed more often
men more commonly diagnosed
general critieria for diagnosing SZ
- report 2 symptoms must be present over 1 month period
2.reduced social functioning
how do DSM-V and ICD-10 differ in their diagnostic criteria for SZ
DSM-V states you need at least one postive symptom present
ICD-10 states need at least two negative symptoms are sufficient
what are the SZ symptoms
Speech poverty -
Avolition -
Delusions +
Hallucinations +
hallucinations
auditory or visual
delusions
irrational beliefs/paranoia
avolition
finding it difficult to keep up with goal directed activity
lack of energy, lack of persistence, poor hygiene
speech poverty
reduction in amount and quality of speech
type 1 SZ
-characterized by positive symptoms
-symptoms which are an addition to the person
type 11 sz
-characterised by negative symptoms
-normal emotions and actions effected
-things are taken away from person
what is diagnosis
identifying a disease on basis of the identification of the symptoms and signs
validity
-the extent to which something is true
extent to which a diagnosis accurately represents disorder they are suffering from
inter-rater reliability in relation to SZ
the extent to which psychists can agree on the same diagnosis when independently assessing patients
test-re-test reliability in relation to SZ
whether tests used to deliver these diagnoses are consistent over time
A03
Cheniaux et al
-had two psychriatists diagnose 100 patients using both DSM-V and ICD-10 criteria
-1 psychiatrist diagnosed 26 with schziophrenia with DSM
-44 according to ICD
-other psychosts diagnosed 13 accoriding to DSM and 24 according to ICD-10
-conclusion-inner-rater reliability is low
1 26 44
2 13 24
what were the results of both psychiatrists
DSM-V ICD-10
26 44
13 24
A03 Rosenhan
-aim-how reliable is diagnosis of SZ
-sent 7 volunteers, and he took part himself
-they had to fake being SZ without having symptoms
-said they had symptoms, ‘heard voices’ e.g ‘its empty’
-every single one was diagnosed as SZ or bipolar
-when in hospital, acted normally
-took 19 days till discharged
-he was in hospital for 2 months as coudent figure out why he shouldn’t be there
-conclusion-issues with diagnosis system in hospitals were identified
-concludes there not very good at their job
-hard to generalise
-good ecological validity as done in real life hospital
What are the 3 biological explanations of SZ (GOOD NIGHT DICK)
-Genetic explanantion
-Dopamine Hypothesis
-Neural correlates
what are candidate genes
what increase risk of sz
candidate genes for sz include
aetilogically heterogenous
polygenic
aetiologically heterogenous
different studies show different candidate genes for SZ
suggests its aetologically hetergenous meaning different combinations
polygenic
needs several factors to work together
ripke et al
what is dopamine
neurontransmitter
hyperdopaminergia in sub-cortex
-too much dopamine
-high levels of activity of dopamine in sub cortex (central area of brain)
-e.g. excess of dopamine receptors in Broca’s area may result in speech poverty
dopamine hypothesis
sz results in in excess levels of neurotransmitter, dopamine
different view is that neurons in sz patients are oversensitive to dopamine
therfore rpoduced overexaggerated respinse and realy unncessary messages to brain
hypodopaminergia in the cortex
cortex=outer layers of brain
-too little dopamine
-Goldman
-identified role for low levels of dopamine in pre-frontal cortex (decision making and thinking) in negative symptoms of SZ
-
neural correlates
measure of the structure and function of brain that correlate with experinece
-positive symptoms
-negative symptoms
neural correlates-positive symptoms
allen at al
typical antipsychotics
example-chlorpromazine
-can be taken as pill/syrup or injection
-not taken often
-most start between 400-800mg of dosage
-max dosage is 1000mg
-does declined over past 50 years
how do typical antipsychotics work
-bind to D2 receptors on neuron without stimulating reduction of dopamine
-block dopamine receptors in brain
-according to dopamine hypothesis, dopamine neurotransmitters can stop hallucinations
atypical antipsychotics
-newer then typical psychotics
-have LESS side effects
-quite effective
-lower dosage 300-400mg a DAY
-has side efefct called agranulocytosis-blood condition where white blood cells are reduced
test-re-test
whether tests are consistent over time
weakness-symptom overlap
overlap between symptoms of schizophrenia and other conditions
Ophoff et al
assessed genetic material from 50,000 participants
found seven locations of genome of SZ , 3 of them also associated with bipolar
suggests genetic overlap between the two
what are the biological explanations of SZ
GND
genetic explanation
neural correlates
dopamine hypothesis