Lecture 20- Anxiety

Question 1

define anxiety

Answer 1

a feeling of worry, nervousness, or unease about something with an uncertain outcome

Question 2

Symptoms

Answer 2

• Palpitations
• Sweating
• Trembling or shaking
• Dry mouth
• Difficulty breathing
• Chest pain or discomfort
• Nausea or abdominal distress (e.g. butterflies in stomach)
• Feeling dizzy, unsteady, faint or light-headed

Question 3

Why do we get anxious?

Answer 3

• Fight or flight e.g. cave man response to danger
• To stay safe and preserve the gene pool to reproduce
  
  • Activates motor system e.g. to run away
  • Activates sympathetic nervous system
    
    • Increased HR and forced contraction
    • Dilated bronchi

Question 4

the stress reaponse linked to

Answer 4

• Limbic- hypothalamus-pituitary-adrenal axis

Question 5

the limbic system is made up of

Answer 5

• Hippocampus formation
  
  • Hippocampus, dentate gyrus, part of the Para hippocampal gyrus
• Septal area
• Amygdala
• +/-
• Prefrontal cortex
• Cingulate gyrus

Question 6

The hippocampus

Answer 6

• Involved in memory and expressions of emotion
• Curved piece of cortex
• Folded into medial surface of temporal lobe
• Occupies floor of temporal horn of lateral ventricle
• Three parts: subiculum, hippocampus proper, dentate gyrus

Question 7

The amygdala

Answer 7

• Buried in the roof of lateral ventricle
• Collection of nuclei
• Inputs of sensory information, brainstem, thalamus, cortex
• Outputs to cortex, brainstem and hypothalamus
• Drive related behaviours and processing of associated emotions

Question 8

Prefrontal cortex and anterior cingulate gyrus

Answer 8

Both have modulatory effect on processes associated with the hypothalamus

Question 9

Hypothalamus

*

Answer 9

Many connections to different areas

Hypothalamic activation increases

• CRH (cortisol releasing hormone) which causes the AP to secrete ACTH (adrenocorticotropic hornone) which cases the adrenal cortex to release cortisol
• Cortisol causes
  
  • increase of energy metabolite levels
  • suppression of the immune system
  • inhibition of allergic and inflammatory processes

Question 10

When does the stress response become a problem?

Answer 10

When the threat is a psychological response and not physical e.g. being chased by a tiger

e.g. not natural when you cant run away

Stress is not always bad… however when there is too much it becomes counter intuitive

Question 11

outline the fight or flight response that originates from the hypothalamus

Answer 11

1) Adrenal medulla activation- adrenaline
2) Adrenal cortex activation- steroids

Question 12

what allows maintenance of stress

Answer 12

cortisol (longer acting than adrenaline)

Question 13

general adaption syndrome

Answer 13

1. alarm reaction
2. resistance
3. exhaustion

Question 14

anxiety disorders

Answer 14

Question 15

Aetiology of anxiety disorders

Answer 15

Cant diagnose people this way

Question 16

GABA and anxiety disorders

Answer 16

• GABA is the main inhibitory neurotransmitter
• GABA levels are decreased in cortex in patients with panic disorder
• Benzodiazepines increase GABA transmission so reduce anxiety
  
  • Quick fix

Question 17

Serotonin and anxiety disorders

Answer 17

• Increased levels of serotonin (due to SSRIs) may stimulate serotonin receptors in hippocampus
  
  • SSRI- serotonin selective reuptake inhibitors
    
    • SSRI block serotonin reuptake so more remains in synaptic cleft
• Leads to neuroprotection, neurogenesis and reduction of anxiety ​

Question 18

Treatment of anxiety disorders

Answer 18

• Mainstay of treatment is SSRIs
  • Cognitive behavioural therapy
  • Can use pregabalin – a GABA analogue

Don’t use benzodiazepines long term

Question 19

why shouldnt you take benzodiazepines long term

Answer 19

• Benzo withdrawal- makes you feel good quickly, become tolerance- Benzo withdrawal
• Loads of side effects

Question 20

Cognitive behavioural therapy

Answer 20

Question 21

OCD is primarily characterised by

Answer 21

obessessions and compulsions

Question 22

obsessions

Answer 22

Thoughts that persist and dominate an individual’s thinking despite their awareness that the thoughts are either entirely without purpose, or have persisted and dominated their thinking beyond the point of relevance or usefulness

Unpleasant and repugnant, often causing anxiety

Question 23

Compulsions

Answer 23

A motor act (or sometimes a thought) resulting from an obsession

Acting out a compulsion may relieve the anxiety provoked by its associated obsession, but frequently carrying out the compulsion is also unpleasant

Question 24

obsessions are…..

Answer 24

always unpleasant

Question 25

to neutralise obssessions people with OCD

Answer 25

**develop compulsions (aka neutralising rituals)** * ‘obsessional **motor acts**. May result from an obsessional impulse that **leads directly to the action**, or they may be mediated by an obsessional **mental image** or fear’ * e.g. ‘I need to turn the light switch on and off ten times or my family will die’ * Can lead to patients wasting a lot of time! * Can also have mental compulsions e.g. repeating phrases

Question 26

**Diagnostic criteria for OCD**

Answer 26

* Obsessions and/or compulsions must be present on most days for at least 2 weeks * Obsessions and compulsions have the following features: * Originate in the mind of the patient * Repetitive and unpleasant * Acknowledged as excessive or unreasonable * Patient tries to resist, but at least one obsession/compulsion is unsuccessfully resisted

Question 27

**OCD pathophysiology (theories)**

Answer 27

unclear

Question 28

hypotheses of OCD pathophysiology

Answer 28

* Basal ganglia re-entrant circuits * Reduced serotonin levels * SSRIs help * Altered activity in a range of cortical areas (cause or effect?) * Autoimmune aetiologies

Question 29

OCD and basal ganglia re-entrant circuits

Answer 29

* The cortex projects to the basal ganglia, and these then project back up to the cortex via the thalamus * This is an example of a ‘re-entrant’ loop, where obsessional thoughts can re-enter the cortex having entered the basal ganglia * This may be due to overactivity in the direct pathway * Treatments that inhibit thalamic (and hence cortical) activity by reducing the direct pathway or increasing the indirect pathway may hold promise (e.g. subthalamic nucleus stimulation)

Question 30

autoimmne aetiologies of OCD

Answer 30

* There may be cross-reactivity with certain streptococcal antigens and the basal ganglia (PANDA)

Question 31

**OCD Treatment**

Answer 31

* **Biological** * SSRIs +/- antipsychotics * Deep brain stimulation? * **Psychological** * CBT and variety of other interventions * **Social** * Family support * Groups etc.

Question 32

**Post traumatic stress disorder**

Answer 32

* Within 6 months of a traumatic event of exceptional severity e.g. in a warzone, torture, not relationship breakdown * Evidence of trauma * Repetitive, intrusive recollection or re-enactment of the event in memories, daytime imagery, or dreams * Conspicuous emotional detachment, numbing of feeling, and avoidance of stimuli that might arouse recollection of the trauma

Question 33

**Pathophysiology of PTSD**

Answer 33

* Unclear * Evidence of amygdala hyperactivity causing exaggerated behavioural responses * However, low levels of cortisol!

Question 34

**Treatment of PTSD**

Answer 34

* **Biological** * SSRIs * Maybe short term benzodiazepines * **Psychological** * CBT * Eye movement desensitization reprocessing therapy * **Social** * Charities are particularly active, such as ‘Help for Heroes’