Biological Approach- Explaining OCD Flashcards
What is involved in vulnerability to OCD?
Genes- Lewis (1936), found that of his OCD patients 37% have parents with OCD and 21% had siblings with OCD. OCD runs in the family, genetic vulnerability passed down. (Diathesis stress model)
What are candidate genes?
Genes which create vulnerability for OCD, regulating serotonin, 5HT1-D beta is implicated in transport of serotonin across synapses.
What is OCD regarding genes, and what support is there?
OCD is polygenic, caused by combination of genetic variations that increase vulnerability. Taylor (2013) found up to 230 different genes may be involved in OCD, associated with action of dopamine and serotonin.
What is OCD in different people?
Aeitologically heterogenous- origins of OCD vary from one person to another
What is the role of serotonin?
If a person has low levels of serotonin then normal transmission of mood-relevant info doesn’t take place and a person experiences low moods, OCD can be explained by reduce functioning of serotonin system in the brain.
What can be impaired in OCD?
Decision- making. Associated with abnormal functioning of lateral of frontal lobes of brain. Frontal lobe is responsible for decision making and logical thinking, left parahippocampal functions abnormally (associated with unpleasant emotions)
Brief AO3 for genetic and neural explanation
Genetic:
- Research support: Nestadt et al
- Environmental risk factors not accounted
Neural:
- Supporting evidence
- Neural model may not be unique to OCD
AO3 for genetic explanation
Research support: Nestadt et al, people are vulnerable to OCD as a result of their genetic makeup. He found in twin studies 68% of MZ twins shared OCD opposed to 31% of OCD. Person with family member with OCD, 4x more likely to be diagnosed. Genetic influence
Also environmental risk factors. Environment can trigger risk of OCD. Cromer et al 2007, over half of OCD patients in sample had experienced a traumatic event, more severed OCD if trauma. Genetics is only a partial explanation.
AO3 for neural explanation
Supporting evidence. Antidepressants that work purely on serotonin are effective in reducing OCD symptoms, serotonin may be involved in OCD. OCD symptoms form part of conditions known to be biological in origin, Parkinsons disease, muscle tremors. If biological disorders produce OCD symptoms then we can suggest biological factors may be responsible for OCD.
Limitation is the OCD-serotonin link may not be unique to OCD. Many people with OCD also experience clinical depression, co-morbidity. Depression also involved disruption to action of serotonin. We do not know if down to OCD.
