The biological approach to explaining OCD Flashcards
Biological approach
a perspective that emphasises the importance of physical in the body such as genetic inheritance and neural function
Genetic explanations
genes make up chromosomes and consist of DNA which codes the physical features of an organism and psychological features
Neural explanations
the view that physical and psychological characteristics are determined by the behaviour of the nervous system
Genetic explainations
- this believes that OCD is inherited & therefore caused by genes from our family in order to study this we look at twin studies & family studies.
- Aubrey Lewis (1936) found that of his OCD patients 37% had parents with OCD and 21% had a sibling with it. suggests that it does run in families, although what is probably passed on from 1 generation to the next is genetic vulnerability not the certainty of OCD.
Candidate genes
- genes which create vulnerability for OCD
- some of these genes are involved in regulating the development of the serotonin system
OCD is polygenic
- OCD is caused by several genes, not just one single gene
- Steven Taylor 2013 has analysed findings of previous studies and found evidence that after 230 different genes may be involved in OCD changed. I’ve been studied in relation to OCD include those associated with the action of dopamine as well as serotonin. Both neurotransmitters believed to have a role in regulating mode
Different types of OCD
- one group of genes may cause OCD in one person but a different group of genes may cause the disorder in another person - known as AETIOLOGICALLY HETEROGENOUS.
- There is also evidence that different types of OCD may be the result of particular GENETIC VARIATIONS, such as hoarding disorder and religious obsession.
Neural explainations
- the genes associated with OCD are likely to affect the levels of key neurotransmitters as well as structures of the brain
- Role of serotonin
- Decision-making systems
The role of serotonin
- Serotonin is believed to help regulate mood
- Neurotransmitters are responsible for releasing information from one neuron to another
- If a person has low levels of serotonin, the normal transmission of murder relevant information does not take place and mood, and sometimes other mental processes are affected
- So some cases of OCD may be explained by a reduction in the functioning of the serotonin system in the brain
Decision making systems
- some cases of OCD, particularly hoarding disorder seem to be associated with impaired decision making
- This may be associated with abnormal functioning of the lateral of the frontal lobes of the brain
- Frontal lobes are the front part of the brain that are responsible for logical, thinking and making decisions
- There’s also evidence to suggest that an area called the left parahippocampal gyrus associated with processing, unpleasant emotions, functions, abnormally in OCD
Strength of the biological approach to treating OCD - genetic- research support
strength: strong evidence
- There is evidence from a variety of sources for the idea that some people are vulnerable to OCD as a result of their genetic make up
- One of the best sources of evidence for the importance of genes is twin studies
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, the strongly suggest a genetic influence on OCD - family studies where research has found that a person with a family member diagnosed with OCD is around four types likely to develop it as someone without
Limitation of the biological approach to treating OCD - genetic- environmental risk problems
- Seems that environmental factors can also trigger or increase the risk of developing OCD
- Kiara Cromer et al 2007, found that over half the OCD patients and their sample had a traumatic event in theirpast, and that OCD was most of it in those with more than one trauma
- This suggests that OCD cannot be entirely genetic in original. It may be more productive to focus on the environmental causes, because we are more able to do something about this
Strength of biological approach to treating OCD - neural - research support
- There is evidence to support the role of some neural mechanisms and OCD
for example, some antidepressants work purely on the serotonin system, increasing levels of this neurotransmitter
Such drugs are effective in reducing OCD symptoms, and they suggested the serotonin system is involved in OCD
- Also, OCD symptoms form part of a number of other conditions are biological in origin. For example Parkinson’s disease
- The suggest that the biological processes that causes symptoms in those conditions may also be responsible for OCD
Limitation to the biological approach to treating OCD - neural - no unique neural system
limitation: serotonin, OCD link may not be unique to OCD
- Studies of decision-making is have shown that these neural systems are the same system as a function abnormally an OCD
Cavedini et al 2002 - However, research has also identified other brain systems that may be involved sometimes, but no system has been found that always plays a role in OCD
- Therefore, we cannot really claim to understand the neural mechanisms involved in OCD
