Anxiety Flashcards
anxiety is adaptive … until:
- It becomes too long (duration),
- It becomes too intense (intensity)
- It is inappropriate to the scenario (appropriate of response)
- There is interference and distress
Rates of Anxiety Disorders
- 18% in US population experience one of the six DSM anxiety disorders
- 29% develop the disorder at some point in their lives
- One third of these individuals seek treatment
High comorbidity: 22% have 2 diagnoses and - 23% have 3 or more diagnoses
Neurobiology of Anxiety
there is no “centre” in the brain specifically for emotions, each area of the brain has its systems and they all contribute to brain functioning,
- Therefore anxiety disorders arise from disruptions to these highly interconnected systems, normally in areas where our brains are trying to detect stimuli from the outside world
- When information is processed it is assigned an emotional value to environmental stimuli, which is operationalised as “interpretation”
- It also weighs the potential threats against competing needs, which is operationalised as “evaluation”
= Once it is perceived as threatening it can drive an observable anxiety-like response
Hence, disruptions in the networks lead to misinterpretations of the sensory information as threatening and thus lead to inappropriate emotional responses
- More likely to interpret a neutral stimulus as threatening
Using Disease Models to Study Anxiety
- Predictive validity: all treatments that alleviate or worsen symptoms in the disease should have the same effect in the model, and vice versa
- Face validity: the symptom-eliciting procedure, the elicited symptoms, the treatment response and the underlying physiology should all be similar to what is observed in the disease
- Theoretical basis: the rationale underlying the model should match the disease etiology; this is almost impossible to assess psychiatry, where disease etiology is unknown for many conditions
Cross-Species Anxiety Tests
Do treatments mitigate or change behaviours in rodents tested in humans in the same way as rodents
Elevated Maze Example
- Rat will try go towards the dark and sheltered areas in the maze
- Humans tested in VR also have the tendency to hide in these sheltered areas like the rats
- However, when given benzodiazepine (anxiolytic) there tendency to do this was reduced
Open Field Paradigm Example
- Evolutionary makes sense that animals desire to spend time around the edges of a field, because it is most dangerous in the middle
- Patients with agoraphobia showed the same tendency
- Was alleviated again with the use of benzodiazepine
Alterations to Brain Networks From Anxiety Disorders
- Including a hyperconnectivity between the affective salience network and the cognitive control network has been shown to elicit changes to inter-network connectivity
- As well as hyperconnectivity within the affective salience network has been shown to elicit changes to intra-network connectivity
Example
- Within the nodes of the affective salience network (amygdala, caudate, nucleus accumbens etc) they test to see how they relate to differential activation across the brain
- Hyperactivation to the networks that produces differential activation between them
Comparing Pathological Anxiety to Induced Anxiety
- Some overlap
- Studying anxiety by inducing anxiety and then testing the effects of the intervention or construct we are interested in
- Specific phobia was modelled best, because they elicit the biggest fear reactions
Fear Generalisation
anxiety disorders having shared cognitive features
- classic conditioning
- Get fear stimulus with shock (fear conditioning), and then test group with no stimulus with shock (generalisation test) to see fear generalisation
- The more fear reaction I show to the intermediate stimulus that is getting further away from the fear stimulus, then the greater fear generalisation there is
- Most characteristic of generalised anxiety disorder
Preferential Processing of Threat-Relevant Information
anxiety disorders having shared cognitive features
Attentional Bias
- People with fear are more likely to be paying attention for the fearful stimuli to arise
- But this attentional bias can have low reliability, meaning that if it is tested multiple times it might not have the same results
- Argument that is just general cognitive deficits that is being seen
Interpreting Ambiguous information as Threatening
anxiety disorders having shared cognitive features
Interpretation bias
- Increased likelihood to interpret a neutral stimulus as threatening rather than positive or neutral
Example
- Positive and negative faces proceeded to different locations so they attributed these locations to positive or negative stimuli
- When they were then subsequently presented with a neutral stimulus, they would attribute it to either positive or negative locations
- Displaying a positive or negative bias
- If they were quicker with either a negative or positive condition then that would describe a positive or negative bias
