biological approach to explaining OCD

Question 1

explain the role of Candidate genes in genetic explanations

Answer 1

• they are genes implicated in the development of OCD
• sert regulates serotonin and low levels of serotonin have been found in people with OCD
• comt regulates dopamine and high levels of dopamine=found in people with OCD

Question 2

what are 2 possible candidate genes in OCD?

Answer 2

SERT- serotonin

COMT-dopamine

Question 3

explain different types of OCD for genetic explanations?

Answer 3

1. (heterogeneous)
   one group of genes may cause OCD in person A, but another may cause OCD in person B
   -may be different groups of genes for different types of OCD
2. polygenic
   not caused by a single gene but there are several involved

Question 4

what are the 2 points for neural explanations?

Answer 4

• the role of serotonin

- decision-making systems (brain structure)

Question 5

explain the role of serotonin for neural explanations

Answer 5

• some OCD can be explained by the reduction of serotonin in the brain
• if a person has low levels of serotonin normal transmission and mood relevant info is affected

Question 6

explain the role of decision making systems (brain structure)

Answer 6

• OFC is the decision maker in the brain
• worries about social/other behaviours
• in OCD the OFC is overactive
• OFC is overactive due to low serotonin sends worry signals to caudate nucleus
• caudate nucleus is damaged in OCD
• caudate doesn’t surprise worry signals and becomes excited and worries/compulsions= OCD

Question 7

evaluate why there is ‘good supporting evidence’ for the genetic explanation

Answer 7

STRENGTH
lewis
-37% patients w/ OCD have parents with OCD and 20% have siblings w/ OCD
-genes passed on mean they have a vulnerability to OCD not a certainty (diathesis-stress model)
-supports OCD it is partly due to their genes

Question 8

evaluate why there are too many candidate genes for the genetic explanation

Answer 8

WEAKNESS

• psychologists cannot find which genes cause OCD
• because is it polygenic and has little predictive power due to so many genes being involved
• therefore genetic explanation is useless as has little predictive power

Question 9

evaluate why there are ‘environmental risk factors’ for the genetic explanation

Answer 9

WEAKNESS

• environmental factors can trigger OCD
• research found that more than half w/ OCD had a trauma in their life =those w/ trauma had more server OCD
• shows it isn’t all genetic and we should focus on environmental cases more

Question 10

evaluate how antidepressants support the neural explanations

Answer 10

STRENGTH

• antidepressant work on serotonin increasing levels=reducing symptoms
• suggests serotonin is involved in OCD

Question 11

evaluate why ‘it’s not clear what neural mechanisms are involved’ in the neural explanation

Answer 11

WEAKNESS

• studies have shown neural systems function abnormally in OCD
• research has shown other brain systems may be involved
• but no system has been found to ALWAYS play a role in OCD
• we can’t then understand neural mechanisms involved

Question 12

evaluate why ‘we should NOT assume neural mechanisms cause OCD’

Answer 12

WEAKNESS

• evidence suggests many neurotransmitters/brain structures are not normal in OCD people
• but cannot be said that, the abnormal function caused OCD
• these abnormalities could be a result of OCD