anxietate Flashcards
What is anxiety?
Anxiety is the fear caused by anticipation of danger; threat is not actually present.
What is fear?
An adaptive response to a realistic threat or potentially threatening stimulus.
What is the DSM 5 diagnosis for anxiety?
Excessive worry or fear occurring more days than not, for at least 6 months
At least 3 symptoms or more:
- restlessness
- sleep disturbances
- muscle tension
What are the commonalities among types of anxiety disorders?
There are different types of anxiety disorders such as PTSD and OCD.
They all share symptoms of fear and worry
They engage similar brain areas
They result in similar cognitive impairments
They can be treated with the same drug
What are the symptoms of anxiety?
2 types: noticeable and hidden
eg:
Noticeable: mouth goes dry
Hidden: adrenaline produced for flight and fight
There are also other effects such as poor concentration, negative thinking
what are the circuits in the brain that are related to anxiety
the shortcut
the high road
- What is the shortcut that anxiety takes in the brain?
stars off with info gathered from outside world- visual stimuli that enter eye and reach thalamus. from thalamus they go to amygdala
When startled, the brain activates the amygdala.
The amygdala alerts other brain structures.
The result is a fear response: sweaty palms
- What is the high road path that anxiety takes in the brain?
stimulus enters eye and reach thalamus, then processed through cortical areas that will then reach amygdala and from there we continue in a similar way to reach rest of body via the messages that are sent to the spinal cord
Sensory information reaches the thalamus.
The thalamus sends the information to the visual cortex.
The visual cortex analyses the raw data and decides whether they require a fear response.
If yes, the cortex signals the amygdala and the body stays on alert.
- How is anxiety induced by over-activation of shortcut?
short cut is over activated
Amygdala typically over-activated in response to stimuli if not regulated by GABA.
what is evidence that amygdala is overactivated in people with anxiety
imaging studies
amygdala more activation in patients with anxiety when ppts are shown negative images as opposed to neutral images
activity in the amygdala is not modulated by the intensity of the stimuli
Anxious patients do not distinguish between the intensity of fearful stimuli.
Non-anxious participants: more fearful stimuli = more activation of amygdala
Anxious participants: similar activation of amygdala regardless of the intensity of fearful stimuli.
- How is anxiety induced by under-activation of high-road?
high road less active
less able to make use of informed processes that allow to make more specific response to the extent to which a stimulus is really dangerous
diminished activation of regions that are part of high road - frontal regions
Activity in frontal areas is reduced in anxiety.
Therefore frontal regions do not downplay the amygdala which does not reduce the over-activation.
Less activity in frontal areas with increase of anxiety.
therefore more activity in amygdala with increase of anxiety
What does anxiety do in the brain?
Increases amygdala activity and decreases prefrontal activity.
What are the main neurotransmitters involved in anxiety?
Nerepinephrine
Serotonin
Dopamine
GABA
What is the effect of anti-anxiety medications?
They promote GABA and serotonin effects so that amygdala is less activated and anxiety is reduced.
What does GABA do?
inhibitory role
It controls the activity of the amygdala by inhibiting its reaction to potentially threatening stimuli
If GABA is deficient the amygdala is not downregulated and response to stimuli is amplified
If the process repeats, anxiety occurs
How do anti-anxiety medications work for GABA?
They block the re-uptake of GABA. - blocks transporter
They increase GABA effect at receptors
So activity in brain areas controlled by the amygdala is normalised
How do anti-anxiety medications work for serotonin?
Block serotonin re-uptake so serotonin can be present longer
So activity in brain areas controlled by the amygdala is normalised.
How is anxiety maintained?
maintaining memories that are kinked to adverse event
- Amygdala is linked to the hippocampus (memory hub)
- Memory of stimuli associated with anxiety are stored in the hippocampus
- Info about anxiety-provoking memories is sent to the amygdala which is over-activated
- Anxiety reaction is consolidated
What is the optimal performance for anxiety?
Too little or too much anxiety affects performance.
Middle ground is ideal for optimal performance.
What cognitive abilities are impaired due to anxiety?
impaired cognitive abilities are likely to be those modulated by amygdala or frontal areas - since these areas are impaired in anxiety
Attention and focus
Learning and recall
Perception
Word finding
cognitive performance and anxiety task - perception
emotional stroop task
ppts read word or colour of word
words either neutral or emotional
ppts with high anxiety might take longer or make more errors in processing words which have negative emotional valiance
ppts with high anxiety took longer to process negative stimuli as opposed to neutral ones
negative meaning of words can interfere with processing something like colour
how does anxiety affect attention
attention based task
stimulus detection
how can emotional stimuli modulated attention in stimulus detection task
ppts presented with 2 words, 1 negative, 1 neutral
a probe was presented either where the negative word was or neutral
ppts detected position of probe as fast as they could
ppts took longer to detect the probe when it was on the same side as the negative key word
why is memory retrieval reduced in anxious patients
brain areas responsible for memory formation - hippocampus
hippocampus is affected by anxiety
hippocampus is related to hypothalamus that is involved in releasing chemicals like cortisol
prolonged cortisol release associated with anxiety becomes toxic for the hippocampus
new memories are difficult to generate
How is cognitive performance affected by anxiety?
Memory is poorer in anxious patients.
Memory is affected by emotional context at encoding.
E.g.: patients with high anxiety recalled more words when the words were presented on a negative background than on a neutral background.
