OCD

Question 1

Behavioural characteristics of OCD

Answer 1

• Compulsions (Repetitive behaviour)
• Avoidance (of triggering situations)

Question 2

Emotional characteristics of OCD

Answer 2

• High anxiety
• Embarrassment/shame (they are self aware)
• Disgust (towards source of obsession or at self)

Question 3

Cognitive characteristics of OCD

Answer 3

• Obsessions/Irrational beliefs
• Awareness that Behaviour is Irrational
• Hypervigilance/Selective attention to source of OCD

Question 4

Biological approach to OCD

Answer 4

OCD is caused by genetics and biochemicals

Question 5

Polygenic

Answer 5

More than one gene is required to manifest the trait

Question 6

What are the multiple genes that could cause a polygenic trait called

Answer 6

Candidate genes

Question 7

COMT gene

Answer 7

Regulates the production of dopamine, produces higher levels in OCD patients

Question 8

SERT gene

Answer 8

Affects transport of serotonin, lower in OCD patients

Question 9

Genetic Explanation Evaluation

Answer 9

+ Nestadt et al found 68% concordance rates for monozygotic twins compared to 32% in dizygotic
+ Ahmari found a common gene in mice than display ritualistic behaviour
- Half of OCD cases are related to previous trauma, so this does not account for cases where there is no family history of OCD

Question 10

High dopamine effects

Answer 10

• Hyperactive basal ganglia brain region, which causes repetitive motor actions (compulsions)

Question 11

Low serotonin effects

Answer 11

• Serotonin plays a key role operating the caudate nucleus in the basal ganglia
• Low levels cause poor function in caudate nucleus
• Low levels can cause obsessions

Question 12

Neural explanation evaluation

Answer 12

+ Antidepressants that increase serotonin levels has been shown to reduce OCD symptoms
+ Has positive applications, as these antidepressants can ‘cure’ OCD
- The neurotransmitter levels might be a symptom more than the cause

Question 13

SSRIs

Answer 13

Selective Serotonin Re-uptake Inhibitors (includes Prozac and Fluoxetine)

Question 14

How do neurotransmitters send messages

Answer 14

Presynaptic neurone releases neurotransmitter, travels across synaptic cleft to convey the message to the post synaptic neurone, and then is reabsorbed by the presynaptic neurone

Question 15

SSRI effect

Answer 15

Prevents the reabsorption of serotonin, so it remains in the synapse longer and continues to stimulate the postsynaptic neurone. This reduces anxiety

Question 16

How long does daily SSRI use take to have an impact on symptoms

Answer 16

3-4 months

Question 17

SSRI Evaluation

Answer 17

+ Soomro reviewed 17 studies comparing SSRI to placebo, SSRIs are shown to be more effective, especially when done with Cognitive Behavioural Therapy
+ 70% of patients experience decline in OCD symptoms while on SSRIs
- Severe side effects (indigestion, blurred vision, loss of sex drive)

Question 18

Benzodiazepines (BZs)

Answer 18

• Anti-Anxiety
• Slows the activity of the Central Nervous System (CNS) by enhancing the activity of GABA

Question 19

GABA

Answer 19

• Has an inhibitory effect on neurones
• Reacts with GABA receptors on the outside of neurones
• Opens a channel to increase flow of chloride ions
• Chloride ions make it harder for any other stimulation
• Leads to relaxation

Question 20

Benzodiazepines Evaluation

Answer 20

+ Reduces anxiety levels quickly and gives immediate relief
- Side effects: drowsiness, depression, unpredictable interaction with alcohol
- Ashton: long term BZ users are very dependent, and withdrawal leads to high anxiety
- Body gets used to the drug, so larger doses are needed