1. Exam question
With reference to the study described above, what do the results seem to show about possible influences on the development of OCD?
[4 marks]

2. Mark Scheme

3. Homework
Research SSRIs and bring the information with you to tomorrows lesson.

4. Biological explanation for OCD
4.1.4 Psychopathology:
The biological approach to explaining OCD: genetic and neural explanations

5. Neural explanations
The genes associated with OCD are likely to affect the levels of key neurotransmitters as well as structures of the brain
These are neural explanations
Abnormal levels of certain neurotransmitters
Certain brain circuits may be abnormal

6. Abnormal levels of certain neurotransmitters
Neural explanations
The neurotransmitter serotonin helps regulate mood.
Low levels of serotonin- implicated in the development of mental problems.
Some cases of OCD may be explained by a reduction in the functioning of the serotonin system in the brain.
Abnormal levels of certain neurotransmitters

7. Neural explanations
Neuroimaging (brain scans) techniques have enabled researchers to study the brain in detail and to identify normal brain patterns - this therefore allows for comparisons with abnormal brain patterns
Researchers have implicated a part of the brain known as the basal ganglia.
This area of the brain is responsible for innate psychomotor functions
Rapport and Wise proposed the hypersensitivity of the basal ganglia gives a rise to the repetitive motor behaviours seen in OCD, for example, repetitive washing/cleaning/checking

8. Neural explanations
Other brain areas believed to be involved in OCD include the orbitofrontal cortex (OFC) and the thalamus
The thalamus is a brain area whose functions include cleaning, checking and other safety behaviours.

9. The orbital frontal cortex
Neural explanations
The OFC is involved in decision making and worry about social and other behaviour. In OCD the OFC and the thalamus are believed to be overactive.
An overactive thalamus would result in an increased motivation to clean or check for safety. If the thalamus was overactive the OFC would also become overactive as a result.
An overactive OFC would result in increased anxiety and increased planning to avoid anxiety.
The orbital frontal cortex

10. Neural explanations

11. Evaluation of neural explanations
The role of neurotransmitters
Allows medication to be developed which helps sufferers.
Drugs are not completely effective
Just because administering SSRIs decreases OCD symptoms does not mean that this was the cause in the first place
There is time delay between taking drugs to target the condition and any improvements being made and yet the chemical imbalance is addressed in hours

12. Evaluation of neural explanations
Areas of the brain
Advances in technology have allowed researchers to investigate specific areas of the brain more accurately, and OCD sufferers do seem to have excessive activity in the orbital frontal cortex
Cleaning and checking behaviours are "hard-wired" in the thalamus
The repetitive acts (compulsions) may be explained by the structural abnormality of the basal ganglia but not necessarily the obsessional thoughts.
There are inconsistencies found in the research as no system has been found that always plays a role in OCD
These neural changes could be as a result of suffering from the disorder, not necessarily the cause of it

13. OCD is down to your Biology!
Need to write an article to match the above headline. You should write it for a broadsheet audience.
Must report on at least two pieces of research.
For the picture/image decide on a suitable diagram that would help your target audience understand the explanation.

14. OCD is down to your Biology!
Get into pairs and peer assess the newspaper articles.
WWW
EBI

15. Bringing it altogether
Fill in the blanks, challenge is to fill in the gaps without using your text books.

16. Can you…? Explain the role of genes in OCD. (4 marks)
Explain two limitations of genetic explanations for OCD. (4 marks)
Outline the neural basis of OCD (4 marks)
Briefly describe one argument in favour of a neural basis to OCD. (2 marks)
Evaluate the biological approach to explaining OCD. (8 marks)

17. Essay
Describe and evaluate the biological approach to explaining OCD (12 marks – AS/16 marks A level)