Bio. Explanation of OCD^ Flashcards
Generic Explanation
genes being passed on to children which makes them more likely to have a certain trait
Neural Explanation
characteristics from the nervous system
Lewis’ Study (GE)
observed OCD patients
- 37% parents with OCD
- 21% siblings
OCD can be genetic
- genetic vulnerability
Genetic Genes
COMT - dopamine (motivation)
SERT + 5HT1 D beta = serotonin (mood regulators)
OCD is Polygenic
involes more than one gene
Taylor
- up to 230 genes
Types of OCD
Aetiology
- why a disorder develops
Heterogeneous
- disorders can take different forms
Decision-Making Systems
Frontal Lobe
- decision making
- acting on the compulsions to revieve the anxiety
Parahippocampal Gyrus
- processing unpleasant memories
The Worry Circuit
Orbitofrontal Cortex
- detect worry signals
Caudate Nucleus
- suppress worry signals
Thalamus
- receive signal from other brain regions
Research Support (GE)
- genetic exp. evidence
- Nestadt et al
: 68% with monozygotic twins
: 31% dizygotic twins - Marini & Stebnick
: having family with OCD makes it more likely to have it too - evidence from lots of sources
: some people are more vulnerable - there must be a genetic influence on the develpoment of OCD
Environmental Risk Factors (GE)
- Cromer et al
:over half of their sample had trauma
:more severity = more trauma - OCD does not have only a genetic origin
- genetic vulnerabilty only provides a partial explanation
Support for Neural Explanation (NE)
- Nestadt et al
: OCD can form part of bio conditions - if bio disorder produce the OCD symptoms
- bio factors may also be responsible for OCD
No Unique Neural Explanation (NE)
- Serotonin not only linked to OCD
- OCD with depression (co-morbid)
- depression involves low level of serotonin
: low levels in OCD could be because they are depressed - Serotonin could be unrelated to OCD symptoms
Animal Studies (NE)
- provide evidence
- Ahmari
: genes associated with repetative beh in mice - mice and humans share most genes
: could be generalised - explanation of candidate genes is valid
Correlation & Causality (NE)
- link between neural explanation and OCD is correlational
- serotonin may not be the cause of OCD
- can’t state that lower levels of serotonin causes OCD
- the validity of serotonin causing OCD as well as other neural explanations should be questioned
Diathesis Stress Model
genetic vulnerability for a certain conditions that makes you more likely to get it
envi trigger guarantees you inheriting it
