Biological Approach To Explaining OCD

Question 1

What are biological approaches split into?

Answer 1

Genetic, neural and evolutionary explanations

Question 2

What kind of studies are used to study genetic factors in explaining OCD and how?

Answer 2

. Twin studies comparing identical (share 100% of genes) and fraternal twins (share 50% of genes)
. Family studies

Question 3

What can be said about the concordance rates if genetic factors are important in the development of OCD?

Answer 3

Concordance rates will be higher in identical twins than fraternal twins as the probability of having it is definitely caused by OCD as identical twins share a complete genetic makeup

Question 4

What did Carey and Gottesman (1981) find about genetic factors in the development of OCD?

Answer 4

Concordance rate of 87% in OCD symptoms for identical twins
Concordance rate of 47% in OCD symptoms for fraternal twins

Question 5

What key thing did Van Grootheest et al (2005) find about factors that influence the development of OCD?

Answer 5

Concordance rates for OCD symptoms in identical twins were far from 100%, showing environmental factors are also very important

Question 6

What did Nestadt et al (2000) find?

Answer 6

Chance of getting OCD in lifetime is higher in relatives who have OCD compared to healthy controls

Question 7

Are cultural factors important in the development of OCD?

Answer 7

Fontenelle et al (2004) - OCD patients across the world saw early onsets of OCD and mixtures of obsessions and compulsions, but more patients had aggressive obsessions in Brazil

Conclusion: the features of OCD are independent of culturally variations, so they aren’t important factors

Question 8

What are the two neural explanations of OCD?

Answer 8

Brain dysfunction and serotonin deficiency

Question 9

Which regions of the brain are involved in OCD?

Answer 9

Orbitofrontal cortex (OFC)
Anterior cingulate
Caudate nucleus
Striatum
Thalamus