OCD

Question 1

what is OCD

Answer 1

obsessive compulsive disorder

Question 2

2 elements of compulsive behaviour

Answer 2

compulsions are repetitive
compulsions reduce anxiety

Question 3

explain compulsions are repetitive

Answer 3

typically sufferers of OCD feel compelled to repeat a behaviour, A common example is hand washing.

Question 4

explain compulsions reduce anxiety

Answer 4

around 10% of sufferers from OCD experience compulsions alone. However, the vast majority of compulsive behaviours are performed in an attempt to manage the anxiety produced by obsessions. eg hand washing is a response to the obsessive fear of germs

Question 5

avoidance as a behavioural characteristic

Answer 5

they attempt to reduce anxiety by keeping away from situations that trigger it. For example coming in to contact with germs.

Question 6

3 emotional characteristic of OCD

Answer 6

anxiety, accompanying depression, guilt

Question 7

cognitive characteristics

Answer 7

obsessive thoughts

Question 8

GENETIC EXPLANATIONS:
what are the candidate genes which create vulnerability for OCD

Answer 8

COMT gene and SERT gene

Question 9

what does the COMT gene do

Answer 9

the COMT gene regulates the neurotransmitter dopamine. One variation of the COMT gene results in higher levels of dopamine, which is implicated in OCD

Question 10

what does the SERT gene do

Answer 10

the SERT gene is linked to the neurotransmitter serotonin and affects the transport of serotonin causing lower levels of serotonin which is associated with OCD.

Question 11

explain how OCD is polygenic

Answer 11

Taylor discovered that there are several different genes (up to 230) involved in OCD. OCD is aetiolically heterogenous which means that the origin of OCD has many different causes.

Question 12

one strength of the biological explanation for OCD (family studies)

Answer 12

Lewis examined patients of OCD.
37% had parents with OCD and 21% had siblings with OCD

Question 13

strength of biological approach (twin studies)

Answer 13

Nestadt et al. reveiwed twin studies and found that 68% of identical twins (MZ) experience OCD and 31% of non-identical twins (DZ) experience OCD. Suggests a strong genetic component. However, not 100% so there must be other factors involved.

Question 14

weakness of biological approach (diathesis stress model)

Answer 14

The diathesis stress model suggests that there are also environmental factors involved in triggering the risk of developing OCD. Researcher found that over half of OCD patients had a traumatic event in their past, and OCD was more severe in those who had experienced multiple traumatic events.

Question 15

NEURAL EXPLANATIONS:
what do neural explanations focus on

Answer 15

the role of neurotransmitter such as serotonin and dopamine as well as brain structure

Question 16

what does serotonin do

Answer 16

regulate mood

Question 17

explain the role of serotonin

Answer 17

neurotransmitters are responsible for relaying information from one neuron to another. if a person has low levels of serotonin then normal transmission of mood-relevant information does not take place and mood is affected.

Question 18

explain the role of the orbifrontal cortex

Answer 18

PET scans have found higher activity in the orbifrontal cortex in patients with OCD. Suggests the hieghtneed activity increases the conversion of sensory information to actions (behaviours) which results in compulsions. The increased activity causes patients difficulty switching off or ignoring impulses.

Question 19

basal ganglia

Answer 19

it is a brain structure involved in multiple processes, including the coordination of movement.

Question 20

research support for neural explanation

Answer 20

there is evidence to support the role of antidepressants working on the serotonin system, increasing levels of the neurotransmitter. These drugs are effective in reducing the OCD symptoms.

Question 21

TREATING OCD:
what does drug Therapy aim to do

Answer 21

to increase or decrease levels of neurotransmitters in the brain

Question 22

what does serotonin do

Answer 22

Selective serotonin reuptake inhibitors (SSRI’s) work on the serotonin system in the brain. When serotonin is released from the pre-synaptic cell into the synapse, it travels to the receptor sites on the post-synaptic neuron. serotonin which is not absorbed in to the post synaptic neuron is reabsorbed into the sending cell (pre-synaptic neuron)

Question 23

how do SSRI’s work

Answer 23

SSRI’s increase the level of serotonin available in the synapse by preventing it from being reabsorbed into the sending cell. This increases levels of serotonin in the synapse and results in more serotonin being received by the receiving cell (post-synaptic neuron)

Question 24

how do anti-anxiety drugs help OCD sufferers.

Answer 24

BZ’s work by enhancing the neurotransmitter GABA. GABA tells neurons in the brain to ‘stop firing’ and around 40% of the neurons in the brain respond to GABA. This means BZ’s have a general quietening influence on the brain and consequently reduce anxiety, which is experienced as a result of obsessive thoughts.