psychopathology-OCD

Question 1

what 3 symptoms is OCD characterised by

Answer 1

obsessions which lead to
guilt and anxiety which lead to
compulsions

Question 2

what are obsessions and what do they lead to

Answer 2

disturbing recurrent thoughts which are not based on reality
they lead to guilt and anxiety

Question 3

what are compulsions

Answer 3

repetitive behaviours that people feel an urge to do in order to reduce the feelings of guilt and anxiety

Question 4

what is the behavioural characteristic of OCD

Answer 4

compulsions
a
they are external

Question 5

what is the emotional characteristic of OCD

Answer 5

guilt and anxiety which may lead to depression

Question 6

what is the cognitive characteristic of OCD

Answer 6

obsessions they may adopt cognitive strategies to deal with their obsessions
they are internal

Question 7

what does the genetic explanation of OCD suggest

Answer 7

that we inherit OCD specific alleles on certain genes increase a persons risk of developing OCD.

Question 8

what 2 genes affect OCD

Answer 8

-COMT
-SERT
OCD is polygenic

Question 9

how does the COMT gene affect OCD

Answer 9

Lower activity of the COMT gene causes higher levels of dopamine

Question 10

how does the SERT gene affect OCD

Answer 10

causes lower serotonin

Question 11

how does the SERT gene cause lower serotonin

Answer 11

produces reuptake proteins that carry serotonin back into the pre-synaptic neuron so less is available at the synapse
-long allele produces more reuptake protein so less serotonin is available at the synapse so decreases inhibition of neural activity in post-synaptic neuron- so associated with OCD

Question 12

what are the 2 pieces of supporting evidence for the genetic explanation of OCD

Answer 12

-Lewis
-Nestadt

Question 13

what did Lewis find

Answer 13

examined patients with OCD
37% had parents with OCD
21% had siblings with OCD

Question 14

what did Nestadt find

Answer 14

reviewed twin studies and found that
68% MZ twins shared OCD compared to 31% of DZ twins
big difference in concordance rates shows OCD is partially inherited

Question 15

what are the limitations of twin studies

Answer 15

-assumes MZ and DZ twins have the same amount of shared environment -however MZ twins are more likely to be treated the same (as they look the same) than DZ twins
High concordance rate for OCD in MZ twins might be caused by shared environmental factors

Question 16

what are some useful applications of the genetic explanation of OCD

Answer 16

led to the development of drug treatment as you can target the effect genes have on neural activity
It also helps support the biological explanation if OCD symptoms are reduced with SSRIs

Question 17

who found supporting evidence for the use of drug treatments

Answer 17

soomro carried out a meta-analysis of 17 studies and found 70% of patients found an improvement with symptoms with SSRIs

Question 18

what is an alternative explanation

Answer 18

the diathesis stress model-we have a genetic vulnerability which is switched on by a traumatic life event this explains why we don’t see 100% of people with the genetic default developing OCD

Question 19

describe the neural explanation of OCD

Answer 19

Orbitofrontal cortex-detects a worrying stimulus and decides on an action
Sends this signal to motor cortex-controls movement
Basal ganglia-monitors outcome of actions sends inhibitory signals to orbitofrontal cortex to shut down worry signals
HOWEVER people with OCD have impaired communication between basal ganglia and orbitofrontal cortex

Question 20

describe the signals from the basal ganglia to orbitofrontal cortex

Answer 20

Signals from basal ganglia to orbitofrontal cortex are much weaker so orbitofrontal cortex is less inhibited than it should be and neurons become hyperactive-generates OCD symptoms
Also when these signals are sent this leads to serotonin being released in the orbitofrontal cortex and neural activity is inhibited
HOWEVER people with OCD have lower serotonin levels so less inhibition of orbitofrontal neurons causing the neurons to become hyperactive

Question 21

what is some supporting evidence for the neural explanation of OCD

Answer 21

-Max
-Saxena and Rauch
-Hu

Question 22

what did Max find

Answer 22

studied a girl who had OCD after brain damage. Conducted an MRI and found she had damage to her basal ganglia
Suggests structural damage to the basal ganglia can cause OCD

Question 23

what did Saxena and Rauch find

Answer 23

reviewed brain imaging studies comparing adults with and without OCD. They found an increase in activity in the orbitofrontal cortex with those with OCD suggesting hyperactivity in the OFC causes OCD

Question 24

what did Hu find

Answer 24

compared OCD and non-OCD and found lower levels of serotonin in the OCD suffers showing low serotonin is associated with the onset of the disease.

Question 25

why is this research correlational and not causation

Answer 25

-evidence to suggest OCD pateints have abnormal levels of Neurotransmitters are abnormal brain structure but this does not mean that this is what causes ocd so we cannot draw cause and effect conclusions.

Question 26

What is an alternative explanation for OCD

Answer 26

The two process model We can acquire ocd through classical conditioning eg pairing the dirt with anxiety We can maintain ocd through operant conditioning through negative reinforcement stimulus is avoided so anxiety is reduced

Question 27

who found limitations for the neural explanation of OCD

Answer 27

Aylward-Found no difference between the basal ganglia of those with and without OCD. Structural damage to the basal ganglia and hyperactivity in the OFC may not be the only causes

Question 28

state 2 drugs used to treat ocd

Answer 28

SSRIs tricyclics

Question 29

Explain how SSRIs work

Answer 29

block serotonin reuptake. More serotonin available at the synapse in the orbitofrontal cortex so more inhibition of neural activity In the orbitofrontal cortex reducing hyperactivity of neurons in this region which reduces worry signals that cause obsessions and compulsions

Question 30

Explain how tricyclics work

Answer 30

Tricyclics block the transporter mechanism that reabsorbs both serotonin and noradrenaline so more is available at the synapse

Question 31

State two pieces of supporting evidence for the biological treatment of OCD

Answer 31

-Soomro-70% of the adults with OCD who were treated with SSRIs noticed an improvement in symptoms SSRIs are significantly more effective at reducing OCD symptoms than no treatment -cost-effective compared to CBT (Cognitive behavioural therapy)

Question 32

What are the limitations for the biological treatment of O C D

Answer 32

-Can cause side-effects Soomro-found that patients treated with SSRIs experienced side effects eg-nausea -if patients stop taking SSRIs they may relapse and symptoms may return -may not be effective at treating the underlying cause of OCD Eg-may not treat cognitive factors so may need to combine CBT with SSRIs O'Connor-combing biological and cognitive treatment for OCD could be more effective CBT and SSRIs showed the biggest improvement