The biological approach to explaining OCD Flashcards
What is the biological approach?
A perspective that emphasises the importance of physical processes in the body such as genetic inheritance and neural function.
What are genetic explanations?
Genes make up chromosomes and consist of DNA which codes the physical and psychological features of an organism. Genes are transmitted from parent to offspring.
Explain genetic explanation for OCD.
Genes may create a vulnerability to OCD. There is evidence that OCD runs in families. Lewis (1936) found that 37% of patients with OCD had parents with the disorder. The diathesis-stress model suggests that, along with this vulnerability, the environment may trigger OCD.
What are candidate genes?
- a gene associated with a particular disease
- researcher identified genes, which create venerability for OCD
- Some genes regulate development of serotonin system.
State the types of OCD for genetic explanations.
- polygenetic
2. aetiologically heterogeneous
Explain polygenetic OCD.
OCD isn’t caused by one single gene but that several genes are involved.
Taylor (2013) has analysed findings of previous studies and found evidence that up to 230 different genes may be involved in OCD, including the action of dopamine and serotonin
Explain aetiologically heterogeneous OCD.
Meaning that the origin (aetiology) of OCD vary from one person to another (heterogeneous).
There’s evidence to suggest that different types of OCD may be the result of particular genetic variations.
What is a strength of genetic explanations for OCD?
Research support
Nestadt et al (2010) reviewed previous twin studies and found that 68% of identical twins shared OCD as opposed to 31% of non-identical twins
Research has found that a person with a family member diagnosed with OCD is around four times as likely to develop it as someone without.
What is a limitation of genetic explanations for OCD?
Environmental risk factors.
Cromer et al (2007) found that over half the OCD patients in their sample had a traumatic event in their past, and that OCD was more severe in those with more than one trauma.
Means genetic vulnerability is a partial explanation for OCD.
What are neural explanations?
The view that physical and psychological characteristics are determined by the behaviour of the nervous system, in particular the brain as well as individual neurons.
What is the role of neurotransmitters?
To relay information from one neuron to another.
Low levels of serotonin, means normal transmission is not taking place, therefore OCD can be explained by a reduction of the functioning of the serotonin system
What is the role of serotonin?
Regulate mood
Some cases of OCD seems to be associated with impaired decision making.
What causes this?
Abnormal functioning of the lateral of the frontal lobes of the brain.
Frontal lobes are responsible for logical thinking and making decisions.
Evidence suggests that the left parahippocampal gyrus (processes unpleasant emotions), functions abnormally in OCS
What is the strength of the neural model of OCD?
Research support.
Antidepressant drugs work purely on the serotonin system, increasing levels of this neurotransmitter, which in turn improves mood. Such drugs are also used and effective in reducing OCD symptoms
OCD symptoms are also said to form part of other conditions that are biological in origin. e.g. Parkinson’s disease.
What is the limitation of the neural model of OCD?
There is a lack of understanding what neural mechanisms are involved.
Lacks causality
