6- Anxiety Flashcards
What are the most common type of psychological disorder?
Anxiety disorders
How many people approximately suffer from an anxiety disorder at some point in their life?
30%
How many more people suffer from anxiety disorders than mood disorders?
Twice as much
How many anxiety disorders are recognised by the DSM-5?
9
How is fear characterised in specific phobias?
Persistent and irrational
What are specific phobias of?
Specific objects, activities or behaviours
How is social anxiety disorder characterised?
By overwhelming fear of social situations
How is generalised anxiety disorder characterised?
General anxiety that is not directed towards anything specific
How is panic disorder characterised?
By reoccurring and unexpected panic attacks
How is agoraphobia characterised?
By anxiety in situations where the person perceives their environment as unsafe
How are panic attacks characterised?
Feeling of sudden and intense fear and anxiety
8 physical symptoms of a panic attack
- Rapid irregular heart rate
- Sweating
- Trembling
- Breath shortness
- Chest pain
- Nausea
- Dizziness
- Dry mouth
How long do panic attacks usually last?
Less than 30 minutes
How many anxiety disorders involve panic attacks?
Most
Are panic attacks always triggered by a disorder?
No, they can occur spontaneously
When is the peak of anxiety?
A panic attack
What are physical symptoms of anxiety and panic similar to?
A fear response
What is activated in the fear response?
The sympathetic autonomic nervous system
4 responses triggered by the ‘fight-or-flight’ mechanism
Increased heart rate
Increased blood pressure
Depressed digestive functions
Mobilised glucose reserves
What understanding is also required in order to understand anxiety disorders?
Understanding of brain circuits that control fear responses and the sympathetic autonomic nervous system
Response controlled by the parasympathetic nervous system
‘Rest-and-digest’
How is the sympathetic nervous system controlled?
By activation of the ‘HPA axis’
What does the HPA axis stand for?
H= hypothalamic
P= pituitary
A= adrenal cortex
5 stages of the HPA axis
- Hypothalamus decides if a stimulus is stressful
- CRH released, stimulates pituitary gland to release hormones
- Stimulates adrenal cortex
- Hormone release
- Physical symptoms of anxiety/panic
Where is the amygdala in the brain?
Small brain region next to the hippocampus
Where does the amygdala receive sensory information from?
The cortex, thalamus and hippocampus
How does the amygdala trigger the fear response?
Sending projections to the hypothalamus
When is the amygdala critical?
In the fear response
Where is sensory info from the thalamus and cortex processed, and where is it next passed on to?
Processed in basolateral nucleus, passed on to central nucleus
How has the involvement of the amygdala in fear conditioning been demonstrated?
In recording studies of mice and fMRI studies in humans
When is the amygdala activated?
When seeing fearful faces
What do patients with amygdala damage show and why?
Show much lower fear levels as they process face stimuli differently
What brain damage did SM have?
Complete bilateral amygdala damage
How was SM described?
As very outgoing, extremely friendly and uninhibited
What was SM impaired in and why?
Recognising negative social cues (including fear in facial expression) as she doesn’t pay much attention to the eye region
What was SM unable to detect?
Environmental threats
How did SM display that she had no memory deficit?
She could remember events, they just didn’t cause her to change behaviours
How was no fear response damaging for SM?
Meant that fear conditioning wasn’t established
What is a common MRI finding of people with anxiety disorders?
Overactivity of amygdala to negative stimuli
What is the process of fear conditioning?
Repeatedly presenting a neutral stimulus with an aversive unconditioned stimulus, causing a fear response to the conditioned stimulus
How do patients with amygdala damage respond to fear conditioning?
Don’t show a normal physiological fear response to a conditioned stimulus, but remember the outcome of that stimulus
What response do patients with hippocampal damage show in response to fear conditioning?
A physiological response but no recollection
What is the amygdala associated with?
Emotional association and response
What is the hippocampus associated with?
Fear memories
What is the amygdala important for?
Processing fear and triggering the HPA axis (causing physical symptoms of anxiety and panic)
What is caused by amygdala damage?
Reduced fear response
What is seen regarding the amygdala in anxious patients?
Amygdala overactivity
What is the hippocampus important for?
Fear memories
What was the early treatment of anxiety disorders?
Benzodiazepines
How do benzodiazepines work?
Increase GABA activity
What is GABA and what does it produce?
An inhibitory neurotransmitter, produces sedative/anxiolytic effects
What do benzodiazepines cause in the brain?
Reduced amygdala activity
Why has drug treatment shifted away from benzodiazepines?
Due to dependence concerns
What are now the first treatment choice for most anxiety disorders?
Selective Serotonin Reuptake Inhibitors (SSRIs)
What do SSRIs do?
Increase levels of serotonin
What does a single dose of SSRIs decrease?
Amygdala activation
What does SSRI treatment reduce?
Amygdala activation and hippocampal activity under stress conditions
What is extinction?
Conditioned fear responses are reduced when feared conditioned stimulus is repeatedly presented by itself
How does exposure therapy suppress fear inhibition?
Repeated exposure to CS only generates an inhibitory memory
What occurs in fear conditioning?
CS is repeatedly presented by itself
What is the result of fear extinction?
Conditioned fear response disappears over time
How is it shown that extinction does not equal forgetting?
Memory for association is inhibited but not erased by fear extinction
What brain area is involved in extinction?
Ventromedial prefrontal cortex
What is shown in the brain after exposure therapy for a specific phobia?
Amygdala overactivation disappears after therapy and there is increased frontal cortex activity
Why is there increased frontal cortex activity after exposure therapy?
Greater cognitive control of amygdala fear response
How do the PFC and the amygdala interact?
PFC inhibits the amygdala
What is a similarity between all anxiety disorders?
All characterised by an excessive fear response
How could physical anxiety symptoms be explained?
By HPA activation
When is the amygdala important?
For fear processing and activation of fear response
What brain activity is often key in anxiety disorders?
Amygdala overactivity
What are common treatment options for anxiety disorders?
Benzodiazepines and SSRIs
How do treatments for anxiety disorders act?
To reduce amygdala activity
