Psychopathology: Explanations for OCD Flashcards
(42 cards)
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.