OCD

Question 1

What is OCD?

Answer 1

A condition characterised by obsessions and/or compulsive behaviour

Question 2

What is the OCD cycle?

Answer 2

Obsessive thought > anxiety > compulsion > temporary relief

Question 3

What are the four DSM-5 categories of OCD?

Answer 3

1. OCD: obsessions and/or compulsions
2. Trichotillomania: compulsive hair pulling
3. Hoarding Disorder: compulsive gathering of possessions and an inability to get rid of anything
4. Excoriation Disorder: compulsive skin picking

Question 4

Give two behavioural characteristics of OCD

Answer 4

1. Compulsions: repetitive and reduces anxiety caused by obsessions
2. Avoidance of things that may trigger the obsessions

Question 5

Give two emotional characteristics of OCD

Answer 5

1. Anxiety and distress
2. Co-morbid depression: low mood
3. Guilt and disgust

Question 6

Give four cognitive characteristics of OCD

Answer 6

1. Obsessive thoughts
2. Cognitive strategies to deal with obsessions
3. Hypervigilance: increased awareness of the obsession
4. Awareness of catastrophising thoughts

Question 7

What are the three biological explanations of OCD?

Answer 7

1. Neurochemical
2. Neuroanatomical
3. Genetic

Question 8

Which two neurotransmitters are vital for the development of OCD?

Answer 8

Serotonin and dopamine

Question 9

What is the role of serotonin in the development of OCD?

Answer 9

Low levels of serotonin in the brain means transmission of mood related info does not happen, causing low mood and poor mood regulation leading to anxiety

Question 10

What is the role of dopamine in the development of OCD?

Answer 10

Excess of dopamine means too much dopamine in the synapses, leading to too much information being passed neuron to neuron, leading to compulsive behaviours

Question 11

What are the two brain regions that make up the worry circuit?

Answer 11

Orbito-frontal cortex:
-Responsible for impulsivity
-Over active in someone with OCD and needs serotonin to suppress activity but people with OCD have too little
-Higher number of worries

Basal Ganglia:
-Responsible for suppressing or actioning worries > hyper sensitive in someone with OCD
-Detects more worries from OFC, cannot suppress them so actions worry again > compulsions

Question 12

How is the OFC impaired in someone with OCD?

Answer 12

It is over-active in someone with OCD as it needs serotonin to suppress activity but people with OCD have to little, leading to a higher number of worries

Question 13

How is the basal ganglia impaired in someone with OCD?

Answer 13

It is responsible for suppressing or actioning worries, meaning it is hyper-sensitive in someone with OCD. This means it detects more worries from OFC as it cannot suppress them due to too much dopamine, actions worries over and over causing compulsions

Question 14

What supportive evidence of the neural explanation of OCD did Rapoport and Wise find?

Answer 14

-Used PET scans which suggested that hypersensivity of the basal ganglia gives leads to repetitive motor behaviours such as those found in OCD patients

Question 15

Why is the development of drug treatments a strength of the neural explanation of OCD?

Answer 15

They tackle the imbalance of neurotransmitters and they appear to work, limiting the effects of people diagnosed with OCD

Question 16

What is the cause and effect problem with the neural explanations of OCD?

Answer 16

We don’t know if the various brain structures and neurotransmitters involved in OCD are the underlying cause of the illness

Question 17

How are genes involved in the development of OCD?

Answer 17

-They have a genetic pre-disposition or vulnerability
-Genes linked to OCD affect the levels of key neurotransmitters
-OCD can run in families, which suggests a genetic link so therefore it must be inherited

Question 18

What family study evidence is there for a genetic link in OCD?

Answer 18

Lewis (1936)
-37% of OCD patients have parents with OCD
-21% have siblings with OCD

Question 19

How is Nestadt’s twin study evidence supportive of the genetic explanation of OCD?

Answer 19

He reviewed previous twin studies into OCD and found:

Identical MZ twins = 68%
Non-identical DZ twins = 31%

This tells us that increased rates of OCD are found in genetically identical twins, therefore there is a link between them

Question 20

What are candidate genes?

Answer 20

Genes that may be involved in the development of OCD

Question 21

Define aetiologically heterogenous

Answer 21

Different genes that lead to the same condition

Question 22

Which two genes are particularly important for the development of OCD?

Answer 22

COMT gene > dopamine related
SERT gene > serotonin related

Question 23

How is the COMT gene faulty in someone with OCD?

Answer 23

It is linked to dopamine. The COMT gene is an enzyme that breaks down dopamine in the synapse. Not enough leads to too much dopamine

Question 24

How is the SERT gene faulty in someone with OCD?

Answer 24

It is linked to serotonin. The SERT gene is a mechanism responsible for transporting serotonin across the synapse. Not enough will lead to not enough serotonin

Question 25

How is the diathesis-stress model the best way to use the genetic explanation to explain OCD?

Answer 25

Genes increase likelihood of someone suffering with OCD, but some environmental stress is needed to trigger the condition

Question 26

What is pharmacotherapy?

Answer 26

Treating conditions through the use of drugs that effect the functioning of the brain or bodily systems, most often in psychology through affecting neurotransmitter levels

Question 27

What are the three types of drug treatments for OCD?

Answer 27

-SSRIs -SNRIs -Tricyclics

Question 28

Give an example of an SSRI

Answer 28

Sertraline (an antidepressant)

Question 29

What dies SSRI stand for?

Answer 29

Selective serotonin re-uptake inhibitor

Question 30

How do SSRIs work to reduce OCD symptoms?

Answer 30

Prevents re-absorption and breakdown of serotonin. It increases levels of serotonin in synapses and continues to stimulate post-synaptic neuror

Question 31

What are SNRIs?

Answer 31

A newer class of drug that increases both serotonin and noradrenaline

Question 32

What are tricyclics?

Answer 32

The oldest type of antidepressant that affects the serotonin system similarly to SSRIs. It has more severe side effects so second line of treatment

Question 33

What supportive evidence is there from a meta-analysis into the treatments of OCD?

Answer 33

Soomro et al Meta-analysis of 17 studies show SSRIs more effective than placebo in treating OCD in all studies

Question 34

Give another strength of biological treatments of OCD

Answer 34

is effective as 70% of patients have reduced symptoms

Question 35

Give a limitation of biological treatments of OCD

Answer 35

Side effects include indigestion and blurred vision

Question 36

Give another limitation of biological treatments of OCD

Answer 36

Symptoms may return when people stop taking the drugs