37- Anxiety

Question 1

what is anxiety?

Answer 1

a feeling of unease – e.g. worry or fear – which can range from mild to severe

it’s both a learned an innate adaptive response to fear-inducing stimuli

anxiety becomes a problem when it’s chronic and irrational as an inappropriate stress response to when a stressor is not present or not immediately threatening

Question 2

symptoms of anxiety?

Answer 2

can be psychological and physiological

psychological symptoms - social disturbances, incessant worry

physiological symptoms - tachycardia, shortness of breath, trembling, headaches, dizziness, sweating, fatigue and insomnia

Question 3

what are the causes of anxiety symptoms?

Answer 3

past experiences

issues in everyday life

diet

physical and mental health

alcohol and drugs, psychostimulants

has a genetic basis

Question 4

how does alcohol contribute to causing anxiety symptoms?

Answer 4

alcohol is a CNS depressant - it increases GABAnergic transmission and blocks glutamatergic transmission, disrupting the excitatory-inhibitory neural activity in the brain, allowing the user to feel relaxed

brain has to adapt to counteract this imbalance, which causes low GABA levels and high excitatory glutamate levels

this can trigger anxiety symptoms

Question 5

how do recreational drugs/ psychostimulants contribute to anxiety symptoms

Answer 5

psychostimulants such as cocaine and amphetamine increase CNS activity, causing tremors and shaking

each drug has a mechanism unique to it for causing anxiety-like symptoms

Question 6

describe the genetic role in anxiety

Answer 6

genetic factors are linked to anxiety disorders but aren’t based on a single gene

the genetic basis for anxiety is complicated and likely an interplay between the environment and genetics

Question 7

describe the pathophysiology of anxiety related to the CNS

Answer 7

hippocampus and amygdala regulate the HPA axis

hippocampus is involved in learning and memory - suppresses the HPA axis to prevent excessive cortisol release. underactivity underlies anxiety disorders.

amygdala is involved in emotion and the fear response. stimulates the HPA axis to promote cortisol release. hyperactivity is associated with anxiety disorders.

HPA hyperactivity from CRH over-expression is linked to anxiety-related symptoms as the stress response is regulated by the HPA axis and cortisol release

Question 8

what are the three classifications of anxiety disorders? give examples

Answer 8

anxiety disorders - e.g. social phobias, specific phobias, generalised anxiety disorder

obsessive compulsive disorders - e.g. OCD, hoarding disorder, body dysmorphia disorder

trauma and stressor-related disorders - e.g. PTSD

Question 9

describe generalised anxiety disorder - what is it? associated symptoms and criteria?

Answer 9

ongoing state of excessive anxiety lacking clear reason or focus

symptoms: restlessness, fatigue, irritability, increased muscle tension, difficulty concentrating, difficulty speaking

must have at least 3 of the 6 symptoms, persisting for at least 6 months which affect daily living and can’t be attributed to substance or medical conditions

Question 10

describe specific phobias - what is it? associated symptoms and criteria?

Answer 10

out-of-proportion extreme fears/ anxieties provoked by exposure to a particular situation/ object which often leads to avoidance behaviours

specific phobias have specific triggers - a wide range of them exist

phobia must persist for at least 6 months and impair daily living

Question 11

social phobia - what is it? associated symptoms and criteria?

Answer 11

significant anxiety provoked by exposure to certain types of social/ performance situations

immediate and out-of-proportion fear. anxiety in the face of social interactions, being observed or performing in front of others

phobia must persist for at least 6 months and impair daily living

Question 12

panic disorder - what is it? associated symptoms and criteria?

Answer 12

recurring panic attacks without a seemingly clear cause/trigger

panic attacks are an abrupt surge of intense fear or discomfort, reaching a peak within minutes - can induce a panic cycle

symptoms: panic attacks, increased heart rate, sweating, trembling, shortness of breath, fear of dying

must have at least 4 of the 13 symptoms

Question 13

PTSD - what is it? associated symptoms and criteria?

Answer 13

distress triggered by recalling past, traumatic experiences, triggered by exposure to certain situations

symptoms: recurrent intrusive memories, nightmares, dissociative reasons, psychological and physiological distress at exposure

disturbances must persist for at least 1 month, impair daily living

Question 14

what are benzodiazepines?

Answer 14

a class of GABA-A receptor positive allosteric modulators, act as anxiolytics

Question 15

mechanism of action of benzodiazepines?

Answer 15

benzodiazepine binds to the allosteric site between the alpha and gamma interface of the GABA-A receptor

stabilises the GABA-A receptor binding site in an open configuration

increases GABA affinity its binding site

increase GABA neuroinhibitory actions and helps resolve the imbalance between glutamate-GABA NTs/ excitatory-inhibitory imbalance associated with anxiety disorders

Question 16

compare benzodiazepines to barbiturates

Answer 16

benzodiazepines - considered cleaner compounds, don’t activate other receptors and provide more selective anxiolytic effects
- provide more acute treatment, act quickly

both drug classes are associated with unwanted side-effects, tolerance and withdrawal symptoms

Question 17

effects of prolonged use of benzodiazepines

Answer 17

can lead to tolerance - will require a higher dosage of the drug for effect

additional glutamate receptors may be trafficked to the cell membrane, restoring the initial NT imbalance

sudden withdrawal can result in decreased GABA activity and withdrawal symptoms = individual must be gradually tapered off to help restore inhibitory-excitatory NT balance

Question 18

how does serotonin work as a neurotransmitter?

Answer 18

serotonin is an NT in the PNS and CNS – activates GCPR receptor subtypes and one LGIC subtype (5-HT3)

important in sleep and wakefulness, mood and emotional behaviours

Question 19

mechanism of action of buspirone as a 5-HT1A receptor agonist

Answer 19

buspirone as a 5-HT1A receptor agonist binds and activates 5-HT receptors

activates auto-inhibitory 5-HT1A receptors = initially inhibits 5-HT release

prolonged use (weeks) leads to desensitisation and downregulation of 5-HT1A receptors

leads to increased excitation of 5-HTergic neurons = increases 5-HT release

suppresses GAD symptoms

Question 20

why does buspirone initially lead to a decrease in serotonin?

Answer 20

initially activates 5-HT1A autoreceptors = leads to decrease in serotonin release

this contributes to the delay in its anxiolytic effects

Question 21

side effects of buspirone?

Answer 21

dizziness, nausea, headaches, decrease in arousal from inhibiting noradrenergic neuron activity

Question 22

compare buspirone as an anxiolytic with SSRIs as antidepressants

Answer 22

SSRIs are commonly used for long-term anxiety states = they block serotonin reuptake = increase serotonin availability in synapse

buspirone initially blocks serotonin release = induces desensitisation and downregulation of 5-HT1A receptors = increases serotonin release overtime

Question 23

how does noradrenaline work as a neurotransmitter?

Answer 23

noradrenaline is a major NT of the sympathetic NS for the peripheral and central NS

it activates GCPR receptor subtypes - alpha and beta noradrenergic receptors

affects cardiovascular tone, attention, arousal, sleep and wakefulness

Question 24

how does propranolol work as a beta-noradrenergic receptor antagonist for treating anxiety?

Answer 24

propranolol is non-selective – acts on B1 and B2 noradrenergic receptors

reduces some of the peripheral/physiological manifestations of anxiety - tachycardia, sweating, tremors, GI disturbances - by blocking peripheral sympathetic responses associated with the fight or flight response

its non-specificity for beta-1 and 2 adrenoreceptors means potential side effects on CV and respiratory function

Question 25

what are the three main classes of anxiolytics?

Answer 25

benzodiazepines

5-HT1A receptor agonists such as buspirone

beta-noradrenergic receptor antagonists such as propranolol