lecture 7 Flashcards
prevalence
proportion of a population who have a specific characteristic in a given time period
how us estimated prevalence calculated
if you know info on the samples of the population of interest
how is prevalence calculated
if info of the entire population is provided
prevalence in uk
4.1 per 1000
prevalence gender
affects men slightly more often than women
onset
late adolescence and early adulthood
estimated annual prevalence uk
0.4 or 4 per 1000
incidence
a measure of the number of new cases of a characteristic that arise in a population over a given period
cost of psychosis per year
£11.8 billion a year
other psychotic disorders
schizoaffective disorder, delusional disorder and schizophreniform disorder and brief psychotic disorder
schizoaffective disorder symptoms of
both schizophrenia and mood disorder - rewires having a major depressive or mania episode
delusional disorder
having delusions -persecution , jealousy , grandeur - no other symptoms of schizophrenia
schizophreniform disorder
symptoms must include either delusions hallucinations or disorganised speech
schizophreniform disorder duration
greater than 1 month but less than 6 months
brief psychotic disorder
symptoms must include either hallucinations, delusions or disorganised speech
brief psychotic disorder duration
1 day to 1 month
brief psychotic disorder triggered bt
extreme stress or bereavement
behavioural genetic studies show that schizophrenia is
substantially heritable - 80% of the variance in schizophrenia scores is estimated to be attributable to genetic factors
heritability
proportion of variance that is accounted by genetic factors in a given population
example study of twin study
estimated heritability 79%
concordance rate - 33% for MZ twins and 7% for DZ` Twins
concordance
presence of the same trait in both members of the pair twins
family studies
first degree relatives are 18 times are likely to develop schizophrenia
gottesman
MZ- 48%
DZ-17%
The genain quadruplets
all four developed schizophrenia
genes associated with schizophrenia
COMT, BDNF, DRD2
COMT
associated with executive functioning that rely on prefrontal cortex
BDNF
brain derived neurotrophic factor is critical for the survival of the CNS
drd2
dopamine receptor d2 is a protein that in humans is encoded by the DRD2 gene
genome wide association study
GWAS - hypothesis free methods to identify associations between genetic regions -loci and traits- genetics
enlarged lateral ventricles
fluid filled spaces - implies loss of Brian cells - social behavioural and emotional deficits
decreased prefrontal Brain function
important in language , emotional expression , planning and carrying out plans
hippocampus
learning and emotions
amygdala
emotional response , decision making
thalamus
relaying sensory and motor signals
reduced
grey matter and volume evident
birth complications
perinatal hypoxia
prenatal viral exposure
perinatal hypoxia
oxygen deprivation at birth- as many as 30% of people with schizophrenia have a history of this
prenatal viral exposure
rates were higher when mother had flu in second trimester- critical period of development of CNS
viral infections
mothers immune system to be more active- negatively impact development of brain cells and dopamine systems in the foetus
dopamine theory
disorder due to excess levels of dopamine
drugs that alleviate symptoms
reduce dopamine activity. if induces - increase dopamine- induce psychosis
