Lesson 12: Biological 🌱 approach- explaining OCD (Genetic 🧬 (A) & Neural (B) Explanations

Question 1

What type of disorder is OCD?

Answer 1

OCD- polygenic- many 🧬 cause OCD (candidate 🧬)

Question 2

What are the 2 explanations of OCD in the biological 🌱 approach?

Answer 2

1) Genetic Explanation

2) Neural Explanation

Question 3

What is the Genetic 🧬 Explanation of OCD based on?

Answer 3

Genes 🧬

Question 4

What 2 genes 🧬 in the Genetic Explanation of OCD are thought to be responsible for causing OCD?

Answer 4

1) COMT gene 🧬

2) SERT gene 🧬

Question 5

What is the COMT gene 🧬 & how is it responsible for causing OCD?

Answer 5

COMT 🧬- causes OCD- regulates production neurotransmitter dopamine- ⬆️ levels cause OCD
— ⬆️ dopamine- responsible- drive 🚘 , motivation, 😡

Question 6

What is the SERT gene 🧬 & how is it responsible for causing OCD?

Answer 6

SERT 🧬 (serotonin transport 🧬)- causes ⬇️ levels serotonin (low mood, depressive symptoms)
— Mutation of 🧬 causes OCD

Question 7

What are the evaluation points of the Genetic explanation of OCD?

Answer 7

👎- 🏃‍♂‍ approach- contradicts- 2 process model suggests- learnt by CC & maintained (reward) by OC- 🏃‍♂‍ approach gained support explaining OCD- 🏃‍♂‍ therapies treat OCD
👍- Nestadt (2000)- people- 1st degree relative (OCD)- 5 times ⬆️ likely- get OCD … 👍 OCD transmitted genetically 🧬
👎- OCD ✖️ 100% cause- genetic explanation- ✖️ account psychological 🧠 & environmental factors
👍- Billet (1998)- meta-analysis- 14 twin studies- OCD twice ⬆️ likely in identical (monozygotic) twins 👯‍♂‍ than non-identical (dizygotic) twins 👯‍♀‍- … OCD transmitted- genetics 🧬

Question 8

What is the Neural Explanation of OCD based on?

Answer 8

1) Neurotransmitters

2) Neuroanatomy (🧠 damage)

Question 9

What 2 neurotransmitters in the Neural Explanation of OCD are thought to be responsible for causing OCD?

Answer 9

1) Dopamine

2) Serotonin

Question 10

What is Dopamine & how is it responsible for causing OCD?

Answer 10

Dopamine- OCD sufferers- ⬆️ levels (over-active, repetitive behaviour)
— Over activity in basal ganglia area (in 🧠)-> repetitive motor functions

Question 11

What is Serotonin & how is it responsible for causing OCD?

Answer 11

Serotonin- sufferers- ⬇️ levels (depressive symptoms, obsessive 💭)
— ⬇️ serotonin-> caudate nucleus (uses past experiences to influence future actions & decisions) malfunctioning

Question 12

What are the evaluation points of the Neural explanation of OCD?

Answer 12

👎- cause & effect ✖️ clear- dopamine & serotonin might ✖️ cause OCD- effect of OCD?
👍- research support- anti-depressant drugs- ⬆️ serotonin levels- ⬇️ OCD symptoms … ⬇️ serotonin-> OCD
👎- role of dopamine- questioned- ⬆️ dopamine-> other psychological illness (schizophrenia etc) … ✖️ enough evidence shows ⬆️ dopamine= OCD- combination factors responsible
👍- research support- Ciccerone (2000)- giving OCD patients drugs 💊 to ⬇️ dopamine-> ⬇️ in OCD symptoms- … ⬆️ dopamine-> OCD

Question 13

What is Neuroanatomy & how is it responsible for causing OCD?

Answer 13

1) 🧠 damage-> OCD

2) 🧠 damage affects short term memory- causes doubts- completed recent actions? …-> repetitive 🏃‍♂‍ (compulsions)

Question 14

What are the evaluation points of Neuroanatomy as a cause of OCD?

Answer 14

👎- cause & effect ✖️ clear- 🧠 damage-> OCD or vice versa
👍- uses PET scanning (positron emission tomography)- difference between sufferers & non-sufferers 👀- basal ganglia activity 👀
👎- same part of 🧠 (basal ganglia)- affected by OCD & Tourette’s – symptoms exist alongside each other- … diagnosing difficult- disorder or syndrome?
👍- supporting evidence- Rapoport (1990)- Europe epidemic 😷 (“The Great Sleeping 😴 Sickness”)- widespread viral 🧠 infections- after major ⬆️ in OCD cases reported … shows 🧠 damage caused by viral infection-> OCD