Developmental psychopathology
different approaches
clinical diagnostic approach
by someone profesionally trained
consider frequency of symptoms before diagnosis
emperical quantitative approach
continuous scale used to measure mental health problems
can still used a clinical cutoff
disorders at extreme ends of the distribution
classification
internalising - feelings, emotions (anxiety)
externalising - bhv (attentional problems)
Psychopathology in children and youth
major public health issue
10-25% depending on categories of population
have early onset - 75% before 25y
chronic/ long lasting - 60% in young people, 22-46%
a lot of work going to early intervention
Study of nature and nurture
origins and causes of psychopathologies
why things overlap?
genetics involved?
interactions with environment?
predictions and treatments/ preventions - new drug targets and interventions found/ created
risk reduction interventions
Twin design
phenotypic variation (P) : observed variable
heritability (A, h2): influences of genetic factors
Shared environment (C, c2): any environmental influences that contribute to the similarity between co-twins
non-shared environment(E, e2): any aspect of environmental influences that makes twins different from each other
P = h2 + c2 + e2
heritability (A) = 2(rMZ - rDZ)
Shared environment (C) = rMZ - h2
Non-Shared environment (E) = 1 - rMZ
ACE Model
structure approaching model used
presented as a path diagram
A - additive
C - common environmental effects
E - non-shared environmental effects
Sub-types of antisocial bhv
children w/ onset early antisocial bhv
group w/ callous-unemotiona traits (CU)
group w/out CU
results
more genetically influenced
Co-occurence/ Comorbidity
co-occurence of two different disorders/ disabilities
both can be observed at the same time:
depression and anxiety
ADHD with language problems
reading disability with mathematics disability
ACE Models
separate estimation of genetic A and environmental C-shared, E-nonshared enfluences
assumptions - equal environments
Genetic Variation
what contributed to individual differences and bhvl traits?
humane genome is built with 3 billion base pairs
20-25%
more tha 99% od the DNA sequence is the same for everybody
only 1% of the DNA sequence is variable
Pathologies are polygenic traits
psychopathologies are influenced by polygenic traits - like skin colour
each genetic variant is additive to the others: more specific genetic variants (alleles) - higher risk of psychopathology