Psychopathology: Explanations for OCD Flashcards
OCD can be explained in which way?
Biologically
What are the two parts to the biological explanation of OCD?
Genetic and Neural explanation
What does the genetic explanation of OCD state?
It states that a person is more likely to develop OCD if a family member has it because of the genetics they have passed on. The DNA they have inherited may give them a predisposition to developing OCD.
What are the two main genes that are part of the genetic explanation of OCD?
The COMT and SERT genes
What is the COMT gene?
It regulates the production of the neurotransmitter dopamine. Those with OCD have a mutated COMT gene. Their COMT gene does not function properly.
What is the SERT gene?
The SERT gene appears to be mutated/ changed in those with OCD. The change in the SERT gene can lead to a reduction in the neurotransmitter known as serotonin.
Which researcher provided evidence for the COMT gene? Describe his study and findings
Tukel et al. (2013): He compared 101 patients with OCD and 100 healthy patients (the control group) without OCD. They found that compared to the healthy control participants, the OCD group had lower activity of the COMT gene than normal, and this was related to higher levels of dopamine
Which researcher provided evidence for the SERT gene? Describe his study and findings
Ozaki et al. (2003): They found a mutation of the SERT gene in two different families. 6/7 of the family members with the mutated SERT gene had OCD.
Name a type of study that is good for evidence for the biological explanation of OCD?
Twin Studies
What are monozygotic twins?
Mono= one Zygotic= egg : Identical twins from one fertilised egg and therefore share 100% DNA.
What are Dizygotic twins?
Di= tw Zygotics= egg : Non- identical twins from two seperate fertilised eggs and therefore share 50% DNA
What is compared in twin study research?
Concordance rates
What are concordance rates?
The degree of genetic similarity for a particular trate e.g. OCD
Where can supporting evidence for the role of genetics in OCD come from?
It comes from twin study research by Nestadt et al. (2010)
Outline Nestdat’s research and findings
They showed that out of all the twin study research published to date, the concordance rate in monozygotic twins was higher than dizygotic twins. Monozygotic twins had a 68% concordance rate for OCD if one twin had it and Dizygotic twins had a 31% concordance rate for OCD
How can we criticise Nestadt’s research?
If OCD was purely caused by genetics, we would expect the concordance rates to be 100% for Monozygotic twins as they share 100% DNA. However the concordance rate was only 68% suggesting that there are other factors causing/ influencing OCD (could be explained by environmental factors).
What is meant by the term neural?
Relating to the nervous system (e.g. the brain)
What are the 2 parts we can break the neural explanation of OCD down into?
1) Neurotransmitter levels 2) Abnormal brain curcuit
What have high levels of dopamine been associated with?
They are associated with people who have OCD and particularly compulsive behaviours.
Describe Kim et al. (2007) research and include his findings. What do his findings suggest?
He gave OCD patients drugs that affected their dopamine levels. They found that this was correlated with less compulsion behaviours. These findings suggest that the dopamine neurotransmitter system could play an important role in OCD patients.
What have low levels of serotonin been associated with?
They have been associated with anxiety and OCD.
How does serotonin link to OCD
Serotonin may be removed too quickly from the synapse before it has transmitted its signal.
What research points to the potential influence of serotonin in OCD? Name the researcher, describe his study, talk about his findings and what they suggest?
Evidence for serotonin in influencing OCD comes from Soomro et al. (2009). He reviewed 17 studies into drug treatment for OCD. These 17 studies combined over 3000 participants. These studies compared drugs that affected serotonin levels in the brain with placebos. The results hwoed that these drugs that altered serotonin levels were more effective at reducing symptoms of OCD than placebos.
Name (and describe its function) of one area of the brain thought to be involved in OCD.
The orbito-frontal cotex.
What is the orbito-frontal cortex sometimes reffered to as?
The worry curcuit
What are the 3 main parts of the worry curcuit?
1) The orbito-frontal cortex 2) The basal ganglia (specifically the caudate nucleus) 3) The Thalamus
What is the orbito-frontal cortex responsible for?
It is responsible for our perception of the world. When we are worried, it sends the signal that we are worried to the thalamus.
Whate is the thalamus responsible for?
It is thought to be the center of our perception of pain.
What is the caudate nucleus responsible for?
In a non- OCD sufferer, the caudate nucleus supresses/ filters this worry signal.
What happens to the worry signal in someone with a faulty caudate nucleus?
The thalamus becomes alerted to the worry signal quite strongly and confirms the worry back to the orbito-frontal cortex
An overactive worry curcuit causes what?
Obsessive thoughts. This then leads to compulsive behaviours to cope with this anxiety and worry.
Which research provides evidence for thw worry curcuit and the orbito frontal cortex? Outline their research, findings, and what their findings suggest.
Beucke et al. (2013): They looked at OCD patients who were etiher on mecication, or not on medication. They found that non- medicated OCD patients showed greater activity and connectivity in the orbito frontal cortex. The level of activity in the orbito-frontal cortex was also positively correlated with how severe their OCD symptoms were.
What is one practical application of the biological explanation of OCD?
Drug treatment: Lead to the invention of SSRIs
What does SSRI stand for?
Selective serotonin reuptake inhibitor
What do SSRIs do?
Due to the mutated SERT gene, they correct the imbalance (decreased amount) of the nuerotransmitter serotonin (by increasing the level of serotonin)
What does the success of SSRI drug treatment suggest?
It shows the value that the biological explanation has in helping to improve the lives of people suffering with OCD
What is an alternative explanation to OCD?
The diathesis stress model
What does the diathesis stress model propose?
How biological and environmental factors may be interconnected
What is the diathesis stress model?
Genetics are involved: They create a predisposition or vulnerability to OCD due to certain genes e.g. the mutation of the COMT or SERT gene. The environment is involved: Environmental factors can trigger or increase the risk of developing OCD.
What life events have been found to be more common with those suffering from OCD?
People who have been bullied, abused, or neglected
Outline Cromer et al’s research, his findings, and what his findings suggest
Over 50% of his OCD patients in his sample has a traumatic event in their past, suggesting the biological explanation alone is not sufficient to fully explain OCD, and that the diathesis stress model helpfully offers an explanation for how biology and the environment may be both involved.
How can determinism be used as an evaluation point towards the biological explanation of OCD?
The biological explanation for explaining OCD has been criticised for being deterministic. It states that OCD is determined or caused by internal biological factors such as genetics or neural factors. As a result, people suffering with OCD have no control no contol over their behaviour, they have no free will, and are unable to change. This is a pessimistic view of the condition as it implies they cannot improve and ther obssessive thoughts and compulsive behaviours are innevitable.
