LS12 - Biological Explanations Of OCD

Question 1

Biological Approach

Answer 1

Assumes OCD is caused by genetic and biochemical factors.

Question 2

OCD

Answer 2

OCd is polygenic and has up to 230 candidate genes,

Question 3

2 Genes Responsible For OCD

Answer 3

COMT Gene
SERT Gene

Question 4

COMT Gene

Answer 4

Regulates the production of dopamine, which in high levels is associated with OCD, a variation of the COMT gene leads to increased dopamine and thi variation is more common in OCD patients than normal people.

Question 5

SERT Gene

Answer 5

Affects the transportation of serotnonin, causing lower levels of serotonin, this can lead to OCD and even depression.

Question 6

Genetic Explanation Strengths

Answer 6

Genetic Research Support
Twin Meta Study Analysis

Question 7

Genetic Explanations Weaknesses

Answer 7

Concordance Rate
Linked To Other Illnesses
Behavioural Approach

Question 8

Genetic Research Support (+)

Answer 8

Nestaddt - FOund those people with a first-degree relative that already had OCD was 5 times more likely to get OCD.

Question 9

Twin Meta Study Analysis (+)

Answer 9

Billlet - Did a meta-anaylsis on 14 twin studies and found OCD is twice as likely to be concordant in MZ tiwns compared to DZ twins.

Question 10

Concordance Rate (-)

Answer 10

The genetic concordance rate isn’t 100% therefore it can’t purely be based on genetic factors.

Question 11

Linked To Other Illnesses (-)

Answer 11

Given that it’s polygenic, its genetically linked to Tourettes and Autism. This suggests that OCD is very complex and could be linked to other illnesses.

Question 12

Behavioural Approach (-)

Answer 12

Contradicts the genetic approach, as it suggests the 2 process model, it also gained a large amount of support suggesting it’s a more viable explanation.

Question 13

Neural Explanations

Answer 13

Dopamine and serotnin are neurotransmitters affecting mood, therefore abnormal levels can be linked to abnormal moods.

Question 14

Dopamine

Answer 14

OCD patients have high levels of dopamine, which links to hyperactivity in the basilganglia causing repetitive motor functions i.e. compulsions.

Question 15

Serotonin

Answer 15

Helps operate the caudate nucleus in the basilgangila, and when it’s low, the basilgangila can malfunction leading to obsessions.

Question 16

Neural Explanations Strengths

Answer 16

Drug Evidence
MRI Scan Evidence

Question 17

Neural Explanations Weaknesses

Answer 17

Cause And Effect

Question 18

Drug Evidence (+)

Answer 18

Anti-depressant drugs increase levels of serotnin, which decreases OCD symptoms, giving good evidence that low serotonoin levels cause OCD.

Question 19

MRI Scan Evidence (+)

Answer 19

Menzies - DID MRI scans on OCD patients and their families, and found they had reduced grey matter in key brain region, suggesting the abnormal brain structure can cause OCD and be genetically inherited.

Question 20

Cause And Effect

Answer 20

Neurotransmitters such as dopamine/serotonin, may not be the cause of OCD nand instead may just be symptoms of it.