schizophrenia Flashcards
(50 cards)
what is schizophrenia?
Means a split mind
A mental disorder associated with disconnected thought processes and a loss of contact with reality
Characterised by a profound disruption of cognition and emotion
More commonly diagnosed in men and working class
classification of schizophrenia
Internal classification of disease (ICD-10)
Diagnostic and statistical manual (DSM-5)
positive symptoms
Additional experiences beyond those of ordinary existence
Hallucinations
delusions
speech disorganisation
Hallucinations
unusual sensory experiences
Can be any sense
delusions
Irrational beliefs that seem real
Delusions of Grandeur - important historical figures
Delusions of paranoia - victim of conspiracy(gov)
Delusions of control - under external control
Speech disorganisation
DSM5
Incoherent speech/topic change changes mid sentence
negative symptoms
Reduction/loss of usual abilities and experiences
avolition
Speech poverty
avolition
inability to persist in goal director behaviour
Severe loss in motivation for every day tasks
Poor hygiene
Extreme = catatonic state
speech poverty
Mountain quality of speech is reduced
Delay in responses
ICD10
differences between DSM 5 and ICD 10
DSM5 - one or more positive symptoms to diagnose
Remove subtypes in 2013
Speech disorganisation
ICD10 - 2 or more negative symptoms to diagnose
Still has subtypes
Speech poverty
inter-rated reliability
The extent to which two psychiatrists arrive at the same diagnosis for the same patient
evaluation of diagnosing
Supporting evidence , high reliability and diagnosis of schizophrenia, strong positive correlation for schizophrenia diagnosis using DSM 5
Schizophrenia is comorbid with depression and 50% of cases which is confusing for psychiatrist
Overlapping symptoms of schizophrenia and bipolar so hard to distinguish diagnosed and treat
Contradictory evidence, low reliability and diagnosis. Two psychiatrist asked to diagnose 100 patients 44 diagnosed schizophrenia with the ICD 26 with DSM no consistency
Low validity of schizophrenia diagnosis another experiment and much more likely to be diagnosed using ICD which questions appropriateness
comorbidity
When two or more conditions occur together at the same time
symptom overlap
Similarity between symptoms and other conditions
biological explanations - genetic factors
MZ - 100% shared genes
DZ - 50% shared.
aetiologically heterogeneous - different genes causing same disorder
Polygenic 108 genes
Family studies - gottesman - aunts 2% siblings 9%
candidate genes - ripke et al
Metanalysis and found 108 different genetic variations associated with schizophrenia
evaluation of genetic factors
Only 48% in MZ twins, therefore Jean alone isn’t an explanation
Nature versus nurture shared some same genes but due to environment
dopamine
A neurotransmitter that has an excitatory effect and involved in sense of pleasure/reward
Neural correlates
Patterns of activity in the brain that occur at the same time as an experience
hyperdopaminergia in the sub cortex
High levels of dopamine in the centre of brain original theory
hypodopaminergia in the prefrontal cortex
more recent. Focused on abnormal dopamine systems in the brain.
goldman found role for low levels in PFC thinking and decision-making
neural correlates of negative symptoms
Motivation involves anticipation of reward. Brain area for this is the ventral striatum.
Abnormality in VS = avolition
jackal found lower levels of activity in VS of SZ patients and a negative correlation
Neural correlates of positive symptoms
allen scanned brains of people having hallucinations
lower activity levels in superior temporal gyrus and anterior cingulate gyrus
Reduced activity in these two brain areas is a neural correlate for auditory hallucinations