Psychopathology- Genetic explanation for OCD Flashcards
Genetic evidence has found that ____ degree relatives of people with OCD have a greater vulnerability of developing the disorder.
first
_______ et al (2000) found that first-degree relatives (i.e. parents, siblings or children) of OCD sufferers had a 12% chance of developing the disorder compared to a 3% risk in the general population.
Nedstadt
According to Nedstadt first degree relatives of OCD suffered have a __% chance of developing OCD compared to a _% risk in the general population
12
3
What genes has research found to be responsible for OCD
Candidate genes
What are some candidate genes involved in regulating and producing
Serotonin levels
What neurotransmitter is implicated in OCD
Serotonin
What does an impaired SERT gene lead to
Diminished levels of serotonin
What did Ozaki et al find in relation to an impaired SERT gene
-its a study
The mutation of the gene was found in 2 unrelated families where 6 out of 7 members had OCD
Ozaki found that:
The mutation of the SERT gene was found in _ unrelated families were _out of _ members had OCD
2
6
7
What are the two impaired candidate genes that have been found responsible for OCD
SERT
COMT
What neurotransmitter does the COMT gene regulate production of
Dopamine
What happens to dopamine when an impaired COMT gene is present
Too much dopamine is left in the synapse
What can too much dopamine present in a synapse lead to
Compulsive behaviours seen within patients with OCD
How many candidate genes did Taylor identify that may contribute to OCD
230
What does polygenic mean
A disorder caused by multiple genetic variants
Why is OCD most likely polygenic
As there are so many candidate genes associated with it (230), which suggests it is most likely caused by multiple genetic variants
What does the genetic explanation suggest about the development of OCD
That some people may inherit a genetic predisposition
What concordance rate did Nedstadt identify in MZ twins for OCD
0.67 or 67%
What concordance rate did Nedstadt identify in DZ twins for OCD
0.31 or 31%
Evaluating the genetic explanation
-research from Nedstadt
Nestadt (2010) review of twin studies found a concordance rate of 0.67 (or 67%) for MZ (identical) twins but only 0.31 (or 31%) for DZ (fraternal) twins.
Hence, the closer the genetic relationship to a sufferer the greater the risk of developing OCD
This suggests that genetics are certainly involved in the transmission of OCD
Evaluating the genetic explanation
-Theortical flaw with Nedstadt’s research
However, this research also demonstrates that genes cannot be the only factor in the development of OCD
Because, if genes were the only explanation then MZ twins would show 100% concordance in OCD. As this is not the case, there must also be environmental influences, like imitation of role models
Therefore the genetic explanation of OCD could be seen as theoretically flawed
Evaluating the genetic explanation
-scientific
A strength of the genetic explanation is that it promotes psychology as a scientific discipline
This is because genetics can be studied objectively and reliably using DNA analysis and studying family history (concordance rates)
This would suggests that the genetic explanation of OCD promotes psychology as a scientific discipline
Evaluating the genetic explanation
-biological reductionism
In addition, the genetic explanation may be biologically reductionist ….
This is because it ignores factors other than genes that may affect the development of OCD
Such as the role of early trauma in childhood (which has been repeatedly linked to OCD)
This implies, that although the genetic account of OCD is scientific, its an incomplete explanation of OCD
