L12 - biological approach to explaining OCD

Question 1

what is the COMT gene

Answer 1

causes OCD
regulates production of dopamine
high levels of dopamine = OCD
dopamine regulates drive, motivation and aggression
COMT gene is more common in OCD patients than those without OCD

Question 2

what is the SERT gene

Answer 2

affects transportation of serotonin and causes low levels of serotonin
SERT gene is on chromosome 17, a mutation in this gene can cause OCD
ozaki - 6/7 family members who had OCD had a mutation of the SERT gene

Question 3

strength of genetic causes of OCD

Answer 3

research support - billett
meta analysis of 14 twins - monozygotic twins are 2x more likely to have concordant OCD
so OCD is transmitted genetically

Question 4

2 weaknesses of genetic causes of OCD

Answer 4

• concordance rate for OCD is not 100%, cannot be entirely caused by genetics, doesn’t take into account psychological and environmental factors
• OCD is polygenic (so a single gene is not responsible), genetically linked to other illnesses e.g. autism so the genetic cause for OCD is complex and related to other illnesses, so could be a predisposing factor

Question 5

who did research into genetics and OCD

Answer 5

beekman and cath

Question 6

what did beekman and cath do and what was their conclusion

Answer 6

meta analysis of twin studies and OCD
MZ twins compared to DZ twins
in children and adults - inherited via genes, with genetic influence up to 65% in children and up to 47% in adults
OCD is transmitted genetically, more apparent when examining children

Question 7

strength of research by beekman and cath

Answer 7

large number of data
more accurate and comparable results
research conducted many times

Question 8

2 weaknesses of research by beekman and cath

Answer 8

• twin studies not performed in controlled conditions, data is not very objective or scientific, may affect validity and reliability of results
• gene mapping not taken into consideration, mapping would look at DNA of twins with OCD and compare with twins who do not have OCD, comparison would then be made to make results more valid

Question 9

what is the dopamine neural explanation of OCD

Answer 9

dopamine affects mood
frontal lobes linked to dopamine activity
OCD sufferers = high levels of dopamine
research on animals found that high doses of drugs that enhance dopamine levels can indicate OCD movements

Question 10

what is the serotonin neural explanation of OCD

Answer 10

affects mood
frontal lobes linked to serotonin activity
low levels of serotonin = depressive symptoms and obsessive thoughts
OCD accompanies depression

Question 11

2 strengths of neural explanations of OCD

Answer 11

research support
- anti-depressant drugs increase serotonin levels, leads to reduction in OCD symptoms
- ciccerone: gave OCD patients low doses of risperidone drug which lowered dopamine levels and alleviate symptoms of OCD

Question 12

2 weaknesses of neural explanations of OCD

Answer 12

• neurotransmitters may not cause OCD, may be the effect of OCD - cause and effect
• role of dopamine questioned, high levels of dopamine can cause other illnesses, not just OCD, can cause bipolar and schizophrenia, not enough research to suggest high levels cause OCD, may be a combination of factors

Question 13

what is the neuroanatomy explanation of OCD

Answer 13

OCD may be caused by brain damage
problem in STM causing chain reaction - results in compulsions
OCD patients studied using PET scans, found frontal lobes and basal ganglia were most active parts when shown something dirty
basal ganglia may be overactive - leads to repetitive motor functions

Question 14

strength of neuroanatomy explanation of OCD

Answer 14

uses PET scanning
scientific and objective
allows psychologists to understand cause of OCD
makes results more reliable

Question 15

weakness of neuroanatomy explanation for OCD

Answer 15

cause and effect - low levels of serotonin could cause OCD and obsessions, or it could be a side effect and cause of the OCD