Psychopathology - biological approach to explaining OCD Flashcards
What are the two explanations?
Genetic and neural explanations
Describe the genetic explanation
Genes make up chromosomes and consist of DNA which codes the physical features of an organism and psychological features
Genes are transmitted from parents to offspring (inherited)
Researchers have identified specific genes which create a vulnerability for OCD - candidate genes
- serotonin genes are implicated in the transmission of serotonin across synapses
- dopamine genes are also implicated in OCD and may regulate mood
These are neurotransmitters
OCD is polygenic - it is not caused by one single gene but several genes are involved
One group of genes may cause OCD in one person but a different group of genes may cause disorder in another person
Different types of OCD may be result of particular gene variations such as hoarding disorder and religious obsession
Describe the neural explanation
Neurotransmitters responsible for relaying info from one neuron to another
e.g low levels of serotonin lowers mood
Some cases of OCD in particular hoarding disorder, seem to be associated with impaired decision making
- associated with abnormal functioning of lateral frontal lobes of the brain
- frontal lobes responsible for logical thinking and making decisions
Evidence to suggest that an area called left parahippocampal gyrus is associated with processing unpleasant emotion, functions abnormally in OCD
What is a strength of the genetic explanation?
There is evidence
Explain why a strength for the genetic explanation of OCD is that there is evidence (A03)
Point - One strength is evidence for the genetic explanation of OCD
Evidence - Nestadt reviewed twin studies and found that 68% of identical twins shared OCD as opposed to 31% non identical
Another study in 2012 found that a person with a family member with OCD is around 4 times as likely to develop it as someone without
Explanation - People who are genetically similar are more likely to share OCD
Link - This is therefore a strength as it supports the role for genetic vulnerability
What is a limitation of the genetic explanation?
The existence of environmental risk factors
Explain why a limitation for the genetic explanation is the existence of environmental risk factors (A03)
Point - One limitation is the existence of environmental risk factors
Explanation - Genetic variation affects vulnerability to OCD, there are environmental risk factors that trigger or increase the risk of OCD
Evidence - an example would be a study (Cromer) that found in one sample over half of people with OCD experienced traumatic event. OCD severely correlated positively with n.o of traumas
Link - therefore a limitation as it suggests genetic vulnerability only provides a partial explanation for OCD
What is a strength of the neural explanation?
Supporting evidence
Explain why a strength of the neural explanation of OCD is that there is supporting evidence (A03)
Point - One strength of the neural model is supporting evidence
Explanation - Antidepressants that work on serotonin reduce OCD symptoms. Suggests that serotonin may be involved in OCD
Evidence - OCD symptoms can form part of condition that are known to be biological in origin e.g Parkinson’s disease
Link - it is a strength as is shows that biological factors are likely to be involved in OCD
What is a limitation of the neural model?
No unique neural system
Explain why a limitation of the neural explanation of OCD is that there is no unique neural system (A03)
Point - One limitation of the neural model is there is no unique neural system
Explanation - Many people with OCD also experience depression. Involving disruption to the action of serotonin
Serotonin activity is disrupted in many people with OCD as they are depressed aswell
Link - A limitation as serotonin may not be relevant to OCD symptoms
