Explaining OCD (Biological App.) - PSYCHOPATHOLOGY

Question 1

emotional characteristics of OCD

Answer 1

low mood

fear/regret

Question 2

cognitive characteristics of OCD

Answer 2

obsession

panic/distress

Question 3

behavioural characteristics of OCD

Answer 3

compulsions

withdrawal/avoidance

Question 4

what type of disorder is OCD classed as

Answer 4

an anxiety disorder

Question 5

what are obsessions (within OCD)

Answer 5

internal components - intrusive thoughts

Question 6

what are compulsions (within OCD)

Answer 6

external components - repetitive behaviours

Question 7

why do patients with OCD do repetitive compulsive behaviours

Answer 7

they reduce anxiety

Question 8

what three assumptions are always included in the biological approach

Answer 8

genetics
neuroanatomy
neurotransmitters

Question 9

three genes included in genetic explanations of OCD

Answer 9

COMT, SERT, neurotransmitters (dopamine and serotonin)

Question 10

what does COMT produce

Answer 10

an enzyme that degrades dopamine

Question 11

what type of COMT variant is found in OCD patients

Answer 11

a low activity one

Question 12

what does the impaired inability to degrade dopamine lead to

Answer 12

higher levels of dopamine in the synapse (particularly after stress)

Question 13

what does SERT produce

Answer 13

a protein that transports serotonin back to the presynaptic neuron (reuptake)

Question 14

what type of SERT variant is found in OCD patients

Answer 14

a high activity one

Question 15

what does removing serotonin quickly result in

Answer 15

lower levels of received and shorter duration of serotonin’s effects

Question 16

what are the levels of dopamine like in OCD patients

Answer 16

thought to be abnormally high

Question 17

what are the levels of serotonin activity like in OCD patients

Answer 17

lower amounts

Question 18

what type of neurotransmitter is dopamine

Answer 18

excitatory

Question 19

what type of neurotransmitter is serotonin

Answer 19

inhibitory

Question 20

what is dopamine responsible for

Answer 20

reward, movement, memory

Question 21

what is serotonin responsible for

Answer 21

appetite, control of behavioural impulses

Question 22

where is dopamine released into

Answer 22

emotional, executive and memory areas

Question 23

where is serotonin released into

Answer 23

emotional, memory and muscle-control areas

Question 24

main function of dopamine

Answer 24

habit forming

Question 25

main function of serotonin

Answer 25

impulse control

Question 26

(neuroanatomy) name the abnormal brain circuits within someone with OCD

Answer 26

OFC, thalamus, caudate nucleus

Question 27

action of the OFC

Answer 27

sends signal to the thalamus about things that are worrying

Question 28

action of the thalamus

Answer 28

leads to impulse to act and then stop activity when the impulse lessons

Question 29

action of the caudate nucleus

Answer 29

normally suppresses signals from OFC

Question 30

action of a DAMAGED caudate nucleus

Answer 30

it fails to suppress signals from OFC
thalamus is alerted about minor ‘worry’ signals
sends signals back to OFC acting as a worry circuit

Question 31

OCD process summary - dopamine

Answer 31

COMT activity low -> dopamine levels high -> caudate nucleus underaction (exhausted) -> hypervigilance (anxiety) -> obsessive thoughts

Question 32

OCD process summary - serotonin

Answer 32

SERT activity high -> serotonin levels low -> orbitofrontal cortex overaction -> impulsiveness -> compulsive behaviour