biological approach to explaining OCD Flashcards
one form of biological explanation
genetic explanation
what are genes involved in
individual vulnerability to OCD
Lewis
• observed that of his patients:
37% had parents with OCD
21% had siblings with OCD
suggest OCD runs in the family
diathesis-stress model
certain genes leave some people more likely to develop a mental disorder
what is necessary to trigger the condition?
environmental stress
What are candidate genes for OCD?
genes with create vulnerability for OCD
what are some candidate genes involved in?
development of serotonin system
e.g. gene 5HT1-D beta is implicated in the transport of serotonin across synapses
what does it mean that OCD is polygenic?
OCD is not caused by one single gene but a combination of genetic variations that t significantly increase vulnerability
Taylor
• analysed findings of studies that found evidence that up to 230 different genes may be involved in OCD
genes studied in relation to OCD
those associated with action of dopamine as well as serotonin
both neurotransmitters believed to have a role in regulating mood
aetiologically heterogeneous
origins of OCD vary from one person to another
evidence that different types of OCD may be the result of particular genetic variations
What are the neural explanations of OCD?
genes associated with OCD affect the levels of key neurotransmitters as well as structures of the brain.
low levels of serotonin
normal transmission of mood relevant info doesn’t happen and a person may experience low moods
lateral frontal lobes
responsible for logical thinking and making decisions - hoarding disorder - can’t make decisions
parahippocampal gyrus
associated with processing unpleasant emotions, functions abnormally in OCD
Genetic explanation evaluation: research support
• evidence suggests people are vulnerable to OCD as a result of their genetic make-up. Neatadt et al found 68% of identical twins shared OCD opposed to 31% non identical twins
genetic explanation evaluation: environmental risk factors
Cromer et al found over half OCD clients in their sample experienced a traumatic event in the past and was more severe for those with past trauma
Neural explanation evaluation: research support
• antidepressants working on serotonin are effective in reducing OCD symptoms which suggests serotonin is linked to OCD
• if a biological disorder produces OCD symptoms we may assume the biological process underlie OCD
neural explanation evaluation: no unique neural system
• serotonin-OCD link may not be unique to OCD
• many with OCD also experience clinical depression
• two disorders together = co-morbidity
• it could be that serotonin activity is disrupted in many with OCD because they’re depressed as well
•serotonin may not be relevant with OCD symotkms
