The Biological Approach To OCD Flashcards
(21 cards)
What are genes associated with OCD likely to affect?
The levels of neurotransmitters and the structures in the brain
How can serotonin explain OCD?
The neurotransmitter serotonin is believed to help regulate mood
If a person has low levels of serotonin then normal transmission of mood relevant information does not take place and mood (and sometimes other mental processes) are affected
How does the frontal lobe function in OCD?
what does this mean?
It functions abnormally
An over reactive frontal lobe would result in increased anxiety and increased planning to avoid anxiety
What is the frontal lobe responsible for?
Logical thinking and making decisions
What are the functions of the thalamus?
Cleaning, checking, and other safety behaviours
What did Lewis observe?
That of his OCD patients, 37% had parents with OCD and 21% had siblings with OCD.
This suggests it runs in families
What does the diathesis-stress model state?
Certain genes leave some people more likely to suffer a mental disorder but it’s not certain that some environmental stress is necessary to trigger the condition
What are candidate genes?
Genes identified as creating vulnerability for OCD
Eg. The SERT gene
What does the SERT gene do?
Affect the transport of serotonin
What does polygenic mean?
OCD is not caused by a single gene instead several genes are involved
What did Taylor find about the genes causing OCD?
Up to 230 different genes may be involved
Genes that have been studied in relation to OCD include those associated with dopamine and serotonin
What does the term aetiologically heterogeneous mean?
One group of genes may cause OCD include those one person but a different group of genes may cause the disorder in another person
What are the strengths of the biological approach to explaining OCD?
There is evidence to support the role of neural mechanisms in ocd — some antidepressants works purely on the serotonin system. These are effective, suggesting that the serotonin system is involved
There is evidence that vulnerability to OCD is a result of genetic makeup. — Nestadt et al found 68% of MZ twins shared OCD as opposed to 31% of DZ twins
The diathesis stress model combines nature and nurture
What are the weaknesses of the biological approach to explaining OCD?
It’s not clear exactly what neural systems are involved
There are too many candidate genes so it is hard to identify all genes involved
Environmental factors can also trigger OCD (Cromer et al found over half of patients experienced a traumatic event in their past). It may be more productive to focus on these as we can do something about them
OCD may be due to social learning theory — close relatives of ocd sufferers may have observed and imitated the behaviour
We don’t know if neural dysfunctions cause ocd or if ocd causes neural dysfunctions
How can drug therapy help with OCD?
It aims to increase/decrease levels of neurotransmitters in the brain or to increase/decrease the patients anxiety
They also work in various ways to increase serotonin levels in the brain
What do SSRI’s do?
Works on the serotonin system
Block the reabsorption of serotonin into the presynaptic membrane
What happens if SSRI’s are not effective?
After 3-4 months of they are not effective the dose can be increased or it can be combined with other drugs
What are some alternatives to SSRI’s?
Tricyclics
Anti-anxiety drugs (eg Benzodiazepines)
What are the strengths of the biological approach to treating OCD?
It is effective — supports the idea that serotonin is linked with OCD
— there is clear evidence for the effectiveness of SSRI’s in reducing severity of OCD
Symptoms decline significantly for around 70% of patients taking SSRI’s
Drugs are cost effective and non disruptive — they are good for the economy as they are cheaper than traditional therapies
What are the weaknesses of the biological approach to treating OCD?
Drugs can have severe side effects
It is possible for people to become psychologically dependent on them
Only targets symptoms, doesn’t treat the cause
Marina et al found relapse is common
Koran et al found they are effective for short term treatments but there is little evidence on the long term effects (suggests CBT should be tried first)
