Case 5 - Anxiety lecture

Question 1

what is the Yerkes-dodson law

Answer 1

how anxiety affects performance

Question 2

when does anxiety become abnormal

Answer 2

excessively intense / disproportionate to the stimulus
Triggered by harmless situations, or occurs without a cause
Continues beyond exposure to danger
Can’t be controlled
Causes severe distress
Impairs functioning

Question 3

what is the operational diagnosis

Answer 3

to meet a psychiatric diagnosis in current systems (DSM5, ICD11)
- a person must experience (a) a certain number of symptoms for (b) at least a minimum specified period of time

Question 4

what must the symptoms cause

Answer 4

• significant stress
• be associated with impairment of everyday function

Question 5

what is classification for GAD

Answer 5

• persistent fear and worry
• plus at least three of:
  poor concentration
  restlessness
  fatigue
  muscle tension
  initial (start of sleep) insomnia

Question 6

how long must you have had these symptoms for

Answer 6

more than 6 months

Question 7

what do u exclude while diagnosing

Answer 7

alcohol or street drug missuse
hyperthyroidism
pheochromocytoma

Question 8

what is pheochromocytoma

Answer 8

benign tumour on the puituatiry gland

Question 9

what is the median onset age

Answer 9

30

Question 10

what are the molecular genetic aetiology

Answer 10

GWAS: several risk genes egg chromosome 2p21, 2q12

candidate gene studies e.g serotonin transporter gene

Question 11

what is GABA

Answer 11

the main inhibitory neurotransmitter in the CNS

Question 12

what is GABA synthesised by

Answer 12

decarboxylation of the amino acid glutamic acid

Question 13

what is GABA’s major roles

Answer 13

regulating neuronal excitability and muscle tone

Question 14

what are the GABA receptor

Answer 14

GABAa - multiple ligand binding sites
GABAb - baclofen is a GABA analogue which acts as a selective agonist for GABAb receptors. used clinically as a muscle relaxant

Question 15

features of the GABAa receptor

Answer 15

• transmembrane ligand gates ion channel receptor
• 5 subunits arranged around a central chloride channel
• 5 distinct types of subunit have been cloned to date; alpha, beta, gamma, sigma and p
• GABA binds to the binding pocket between the alpha and beta subunits. this causes CL- ions to flow into the neurone leading to decrease chance of action potential

Question 16

what is the NICE guidance stepped care approach 1

Answer 16

Step 1: recognition and diagnosis of GAD
Step 2: offer treatment in primary care

interventions with positive evidence base:
Psychological therapy (CBT)
Pharmacological therapy - SSRI or benzodiazepines
Self help (online self education)
shared decision making

Question 17

what is the NICE guidance stepped care approach 2

Answer 17

Step 3: non-response: review and offer alternative treatment

Step 4: review and offer referral to secondary care
if 2 interventions have been provided and the person still has significant symptoms, then referral to specialist mental health services should be offered

Step 5: care in specialist mental health services
through reassessment

Question 18

what are the core elements of CBT

Answer 18

• identifies unhelpful patterns of things and how these cause feelings of anxiety
• aims to replace these unhelpful beliefs with more realistic and balanced ones. it mainly focuses on current problems rather than events from the past
• ## the B part is most effective when there are specific environmental triggers

Question 19

how many sessions of CBT does NICE recommend

Answer 19

12 to 15 one hour long sessions over 4 months

Question 20

what is first line treatment for anxiety

Answer 20

SSRI’s

Question 21

benzodiazepines mode of action

Answer 21

bind at a separate site between the alpha and gamma units

this potentiates the action od GABA and increase CL- influx

diazepam is a positive allosteric modulator at the GABAa receptor

Question 22

how do SSRI’s work

Answer 22

block serotonin re uptake from the synapse

Question 23

what are the other antidepressants used in GAD

Answer 23

Mirtazapine (blocks pre synaptic alpha-2 auto receptors)
Duloxetine (SNRI)
Venlafaxine (SNRI)
Imipramine (tricyclic)
side effects differ to SSRIs

Question 24

what is the action of pregabalin

Answer 24

precise action unknown: molecule is structurally similar to GABA. it can bind to the alpha2delta subunit of the calcium channel, decreasing the release of neurotransmitters including glutamate, noradrenaline and substance P

Question 25

how do benzodiazepines differ

Answer 25

mainly in their half life
- diazepam (valium) 30 hours vs triazolam 2 hours

Question 26

where do benzos act

Answer 26

at the GABAa receptor