Evaluation of biological explanation

Question 1

What did Nestadt et al (2010) find?

Answer 1

Support for twin studies of OCD
Found that 68% of identical twins and 31% of non identical twins experience OCD
Suggests its a strong genetic component
Not 100% concordance so other factors involved

Question 2

Strengths of the approach?

Answer 2

• Supporting evidence from anti-depressants which heighten the amount of serotonin, effective in treating OCD

Question 3

Weaknesses of the approach?

Answer 3

• It is reductionist - ignores other factors and cognition and OCD is far too complex to do this
• Too many candidate genes for it to be pinned down to one cause
• environmental risk factors which increase the chance of OCD developing
• Overlook the fact that twins share the same environment as well as genes

Question 4

What are evaluation points for twin studies such as Nestadt et al (2010)?

Answer 4

• Twin studies provide good supporting evidence for a genetic component in OCD
• Never 100% concordance rate - other factors must be involved
• Can’t separate nature and nurture

Question 5

What issues does the polygenetic nature of OCD create?

Answer 5

It is hard to pin down exactly which genes suggesting that each genetic variation only increases the chance of OCD by a fraction, creating no predictive value

Question 6

What did Cromer et al (2007) find?

Answer 6

Half of those with OCD had experience trauma and therefore OCD couldn’t be entirely genetic

Question 7

What do the success of antidepressants show?

Answer 7

Serotonin must be involved in the condition

Question 8

What is a limitation of the serotonin links?

Answer 8

They may be correlational

They may have different levels of serotonin because of the individual having OCD, not the other way around

Question 9

What is co-morbidity? Why is this an issue?

Answer 9

Two conditions occurring at once

An individual may be diagnosed with OCD when its actually depression for example