Anxiety

Question 1

What is the physiological role of anxiety?

Answer 1

Stress response - which results in anxious feeling - enables us to escape from potentially dangerous situations

Question 2

What is the anxiety response mediated by?

Answer 2

Majority the limbic system - hippocampus, amygdala

Also pre-frontal cortex
These systems have neural and endocrine targets

Question 3

Role of hippocampus in anxiety

Answer 3

• Receives inputs from many parts of cortex and processes their emotional content
• Then projects to thalamus (and then back to cortex = Papez circuit) and also the hypothalamus
• Hypothalamus causes emotional response sending projections down autonimic preganglionic neurones
• = sympathetic nervous system activation
• and adrenaline release from adrenal medulla
• Hippocampus also has role in memory - Papez circuit may be involved

Question 4

What is the amygdala?

Answer 4

Almond shaped structure sitting near tip of hippocampus

Question 5

Amygdala role in anxiety

Answer 5

Recieves many inputs from sensory system
Outputs to cortex and hypothalamus
Involved in behavioural and autonomic emotional responses

Question 6

Prefrontal cortex role in anxiety

Answer 6

Modulation of emotional responses - conciously supressing features of anxiety
May be your ‘perception of emotion?’

Question 7

What happens when HPA axis is stimulated by stress?

Answer 7

Hypothalamus paraventricular nucleus releases CRH
Anterior pituitary releases ACTH
Adrenal cortex (zona fasciciulata) to releases cortisol and medulla to release adrenaline

Question 8

What are the endocrine elements of the stress response?

Answer 8

• Limbic system (hippocampus and amygdala) is able to act on hypothalamus to stimulate secretion of stress hormones via HPA axis (adrenal)
• Release of cortisol from adrenal cortex is part of the chronic stress response

Question 9

What is the general adaptation syndrome?

Answer 9

Three stages the body goes through during prolonged exposure to stressors

Question 10

3 stages of general adaptation syndrome

Answer 10

1. Alarm reaction - adrenaline and cortisol are released as well as sympathetic activation
2. Resistance - adrenaline wears off, chronic stress response and prolonged release of cortisol
3. Exhaustion - cannot escape ongoing stressor, chronic side effects of prolonged cortisol exposure start

Question 11

What overall happens in chronic stress?

Answer 11

Less negative feedback on cortisol release = levels continue to rise
Increased activity of amygdala and hypothalamus
= increased acitivty of sympathetic ANS

Question 12

What is stress habituation?

Answer 12

Repeated mild stress exposure leads to a reduced response to HPA axis
Mild stress reduces activity seen in sympathetic ANS

Question 13

When is anxiety a problem?

Answer 13

When response is to a perceieved threat, not an actual one
Difficult to manage
Cannot cope

Question 14

When can chronic stress response/general adaptation syndrome become pathological?

Answer 14

If you cannot escape stressors or when trivial (‘minor’) stressors elicit a strong stress response

Question 15

What is anxiety?

Answer 15

Pathological stress response - anticipatory, future focused

Question 16

Symptoms of anxiety

Answer 16

Primarily due to sympathetic activation:
* Palpitations
* Sweating
* Tembling/shaking
* Dry mouth
* Difficulty breathing
* Chest pain/discomfort
* Nausea or abdominal distress - butterflies
* Dizzy, unsteady, faint or light headed

Question 17

Classification of 6 anxiety disroders

Answer 17

• Social phobia - anxiety about social situations
• Specific phobia - eg spiders
• Generalised anxiety disorder - peristent anxiety about many things
• Panic disorder - recurrent unexpected panic attacks
• Obsessive compulsive disorder
• Post-traumatic stress disorder (PTSD)

Question 18

Pathophysiology of anxiety disorders

Answer 18

Unclear
GABA can be low in some anxiety disorders
Increasing serotonin can help treat anxiety disorders

Question 19

Treatment for anxiety disorders - broad

Answer 19

Biological:
* short term benzodiazepines
* SSRIs

Physiological:
* Cognitive behavioural therpay - reflect on thoughts, feelings and behaviours

Social:
* Support groups, charities

Question 20

OCD epidemiology

Answer 20

• Common - 1 in 50 at some point
• 1/3 cases start between 10-15 years old
• 3/4 started by 30
• Equal male:female

Question 21

What is OCD characterised by?

Answer 21

Obsessions:
* Thoughts that persist and dominate individuals thinking despite their awareness that the thought are without purpose or have persisted beyond the point of relevance or usefulness
* Unpleasant, repugnant often causing anxiety

Compulsions:
* Motor act (sometimes a thought) resulting from obsession
* Acting out compulsion may relieve anxiety caused by obsession but frequently carring out compulsions is unpleasant

Question 22

How long are obsessions and compulsions present in OCD?

Answer 22

Must be present most days for at least 2 weeks

Question 23

Common features of obsessions and compulsions in OCD?

Answer 23

• Originate from the mind of the patient
• Repetitive and unpleasant
• Acknowledged to be unreasonable and excessive
• Patient tries to resist but at least one obesession/compulsion is unsuccessfully resisted

Question 24

Pathophysiology of OCD

Answer 24

Unclear, some theories:
Basal ganglia rentrant circuits:
* Cortex projects to BG, these then project via thalamus back to cortex
* = re-entrant loop may be caused by overactivity of direct pathway
* Treatments inhibit thalamic activity (then cortical) by reducing direct pathway or increasing indirect pathway may help?

Reduced serotonin levels
* SSRIs help

Altered activity in a range of cortical areas

Autoimmune - streptococcal antigens and basal ganglia cross reaction?

Question 25

Treatment for OCD

Answer 25

Bio:
* SSRIs +/- antipsychotics
* Deep brain stimulation?

Psychological and social:
* Cognitive behavioural therapy
* Family support, groups etc

Question 26

PTSD features

Answer 26

• Can occur within 6 months following an exceptionally severe traumatic event (eg rape, war trauma)
• Causes repetitive intrusive recollection or re-enactment of event in memories, daytime imagery or dreams
• = emotional detachment, numbing of feeling and avoidance of stimuli that may arouse recollection of trauma

Question 27

Pathophysiology of PTSD

Answer 27

Unclear
Amygdala hyperactivity causing exaggerated beahvioural response?
But low levels of cortisol

Question 28

Treatment for PTSD

Answer 28

Bio:
* SSRIs
* Short term benzodiazepines

Psychological
* CBT
* Eye movement desensitization reprocessing therpay - follow pendulum with eyes and talk through trauma

Social:
* Charities - eg help for heroes

Question 29

Good thing about anxiety

Answer 29

Moderate levels improve performance - allow for focus and tunnel vision for goal

Question 30

Treatments for phobias

Answer 30

Systematic desensitisation - expose them little at a time to the phobia

Question 31

Whats agoraphobia?

Answer 31

Fear of crowds, open spaces, difficulty to get home

Question 32

Triggers of agoraphobia

Answer 32

Distance from home
Crowding
Open space
Social situations

Question 33

Social phobia - what is it?

Answer 33

Anxiety in social situations due to fear of scrutiny by other people
Feel inferior

Question 34

Psychological symptoms of anxiety

Answer 34

• Fearful anticipation
• Irritability
• Sensitivuty
• Restless
• Poor concentration
• Anxious thoughs

Question 35

What is the basal ganglia re-entrant loop in OCD?

Answer 35

Increased activity in caudate nucleus
= activation of orbitofrontal cortex
= increased activity thalamus via cingulate gyrus
= increased stimulation cortex which projects back to BG