5.4 OCD

Question 1

What is OCD?

Answer 1

A condition characterised by obsessions and/or compulsive behaviour

Question 2

What are obsessions?

Answer 2

Repeated thoughts, urges or mental images that are intrusive and unwanted (cognitive)

Question 3

What are compulsions?

Answer 3

Repetitive behaviours/mental acts that a person feels driven to perform in response to an obsession (behavioural)

Question 4

What are 3 behavioural characteristics of OCD?

Answer 4

• Compulsions are repetitive
• Compulsions reduce anxiety
• Avoidance

Question 5

What are 3 emotional characteristics of OCD?

Answer 5

• Anxiety and distress
• Accompanying depression
• Guilt and disgust

Question 6

What are 3 cognitive characteristics of OCD?

Answer 6

• Obsessive thoughts
• Coping strategies
• Insight into excessive anxiety

Question 7

What are candidate genes + an example?

Answer 7

Genes which create a vulnerability for OCD e.g 5HT1-D (implicated in transportation of serotonin)

Question 8

Why is OCD polygenic?

Answer 8

OCD is not caused by one single gene, but by a combination of genetic variations that together increase vulnerability

Question 9

What is the evidence to support OCD being polygenic?

Answer 9

Taylor (2013): analysed previous studies and found evidence that up to 230 different genes involved in OCD

Question 10

What does aetiologically heterogeneneous mean?

Answer 10

A number of different gene combinations can lead to an illness therefore the origins vary from person to person

Question 11

AO3 for genetic explanations of OCD

Answer 11

1. Research support
Evidence for vulnerability due to genetic make-up, twin studies, Nestadt et al (2010): found 68% of identical twins shared OCD as opposed to 31% non identical twins, family studies show person with family member diagnosed with OCD 4 times more likely to develop it, suggest genetic influence on development of OCD

2. Environmental risk factors
OCD not entirely genetic in origin, environmental factors can trigger or increase risk of OCD, Cromer (2007): over half OCD clients experienced traumatic past event, OCD more severe in patients with one or more trauma, genetic vulnerability only partial explanation

Question 12

What is the frontal lobe responsible for?

Answer 12

Logical thinking and decision making

Question 13

AO3 for neural explanations of OCD

Answer 13

1. Research support
Antidepressants purely for serotonin effective in reducing OCD symptoms, suggests serotonin involved in OCD, OCD symptoms form conditions which are biological in origin. if biological disorder produces OCD symptoms then we may assume biological processes underlie OCD

2. No unique neural system
Serotonin-OCD link may not be unique to OCD, many with OCD also experience clinical depression (2 disorders together=co-morbidity), this depression also disrupts serotonin so serotonin may be disrupted due to depression not OCD, serotonin may not be relevant to OCD symtoms

Question 13

What is the left parahippocampal gyrus responsible for?

Answer 13

Associated with processing unpleasant emotions (functions abnormally in OCD)

Question 14

What is the role of serotonin in OCD?

Answer 14

Helps to regulate mood. If serotonin is low, normal transmission of mood relevant information does not occur leading to low mood levels

Question 15

How do SSRI’s work?

Answer 15

• Prevent reabsorption and breakdown of serotonin by presynaptic neuron
• Increases serotonin levels in synapse and stimulate postsynaptic neuron

Question 16

How are drugs combined with other treatments?

Answer 16

• Often used alongside CBT
• Reduce a persons emotional symptoms e.g anxiety so they can engage more effectively with CBT

Question 17

What are tricylics?

Answer 17

An older type of antidepressant that acts on various systems including the serotonin system where it has the same effect as SSRI’s

Question 18

What are SNRI’s?

Answer 18

A second line of defence for people who don’t respond to SSRI’s. They increase levels of serotonin as well as noradrenaline

Question 19

AO3 for treating OCD

Answer 19

1. Evidence for effectiveness
SSRI’s reduce symptom severity and improve quality of life, Soomro et al (2009): reviewed 17 studies that compared SSRI’s to placebos in OCD treatment, showed better outcome for SSRI than placebo treatment, typically symptoms reduce for 70% taking SSRI’s, drugs helpful for those with OCD

2. Cost-effective and non-disruptive
Cheap compared to psychological treatments, tablets and liquid doses can be manufactured quickly, good value for public health systems and good use of limited funds, patients can take drugs until symptoms decline compared to attending various therapy sessions

3. Serious side-effects
Such as indigestion + blurred vision, side-effects can be distressing, long lasting for a minority, for tricyclics side-effects common and more serious e.g 1 in 10 experience erection problems and weight gain, 1 in 100 experience aggression and heart related problems, drugs cease to be effective