PSYC2020 Practice Questions - Wk 8 Stress, Anxiety, Depression Flashcards
What is stress? 3
A stimulus that disrupts internal balance
A deviation from homeostasis
Mental and physical state induced by stressor
What is fight or flight response?
Survival mechanism - react quickly to life threatening situations
What is a stress response?
Array of neural and endocrine systems that mobilise resources in response to a challenge to homeostasis
What happens in the stress response? 6
Mobilise energy resources Increase blood pressure Think more clearly Enhance learning/memory Sharpen sensory thresholds
What are the two main hormones involved in stress?
Epinephrine (adrenaline)
Glucocorticoids (cortisol)
Why do we only have a single stress response?
Evolution is a tinkerer
What is good stress? 3
Mild, transient, no complete loss of control
What is bad stress? 4
Severe
Chronic
Unpredictable
Lack of control
What does optimal good stress result in ? 3
Arousal, alertness, stimulation
What is the key to optimal good stress? 2
You have control and involves a reward
What was one of the first psychosomatic disorders to be recognised?
Gastric ulcers
Where were Warren and Marshall from? What did they do?
Perth, WA. Discovery H pylori, Nobel prize for drinking bacteria.
What are the main brain areas involved in stress? 3
Amygdala - threat assessment
Hypothalamus - SNS
Pituitary gland
what is involved in stress memory?
Hippocampus
Which area is involved in emotional regulation in stress response?
ACC
Where would be the source of psychological stressors?
PFC
What endocrine system is involved in stress?
Adrenal glands
What are the two parts of the adrenal glands? Where? What do they release?
Adrenal cortex (outer layer): release cortisol Adrenal medulla (middle): release epinephrine
4 characteristics of SAM system?
Fast response
Short acting
Epinephrine
Jump start
4 characteristics of HPA axis?
Slow response
Lasting
Cortisol
Keep things going
In a stress response how is epinephrine involved? 2 stages
The SNS uses epinephrine as neurotransmitter, so there is an initial ‘spritz’. SNS also activates adrenal medulla to dump epi into blood for sustained response.
What are the effects of epinephrine? 4
ERROR!
What are the effects of cortisol in the stress response? 2
Mobilise energy reserves
Redistribute energy from non-essential processes
Which ANS efferent would stimulate digestion and restorative functions?
Parasympathetic
How is the SAM system efficient?
EPI dump starts with nerves and then tells adrenal medulla to start using hormones
Are there ill effects from the SAM system? What might be a counter example?
No bad effects, BUT persistent epi surges can damage blood vessels
How fast is the SAM system?
Very fast - happening before conscious awareness.
what are 3 positive effects of the SAM system on thinking?
- Improve mood
- Encourages creative thinking
- Problems feel like challenges
What is released by the adrenal cortex?
Cortisol
What is the primary function of the HPA axis? How does this help the stress response?
Increase blood glucose -> support extended F or F response
What is the most common physiological measure of stress?
Blood cortisol levels
Which cells in the body have cortisol receptors? Why?
Almost all cells; because its an important steroid hormone involved in multiple body processes
What is the diurnal variation of cortisol?
Large peak in early morning which fades rapidly to midday and is low & sustained for the rest of day
What are body processes which use cortisol? 3
- Stress
- Sleep/wake cycle
- Low blood sugar
What is Addison’s disease?
Someone who cant respond quickly to low blood sugar, because adrenal glands don’t produce enough cortisol
What are the metabolic effects of cortisol? 3
- Release glucose stores in muscle/liver
- Modified fat and protein metabolism
- Gluconeogenesis
What are two ways cortisol can alter the immune system?
- Reduce inflammation
2. Immune suppression (from hyperactivity)
What are 3 systems which can be suppressed by cortisol?
Digestive, reproductive, growth processes
What is a potential problem with the negative feedback control of cortisol?
Because cortisol turns itself down, damage due to excessive cortisol can break the control, leading to chronic stress problems (harder to turn HPA off)
What are the first three areas to receive damage from cortisol?
Hippocampus, hypothalamus, pituitary
What are three determinants of HPA activity?
- genetic factors
- early-life environment
- current life stress
Are there differences in stress response due to sex or age?
Yes
How much of the variance in basal glucocorticoids is accounted for by heritability?
62% - more than half.
What counts as “early-life environment”? 2
Pre and posts-natal influences
Childhood trauma is associated with modified ____? 2. what is the mechanism for this?
HPA axis responsively AND adult offspring (epigenetics)
What happens to rats that receive poor maternal care? 2
They show deficits in hippocampus receptors and impaired shut off of HPA response.
What promotes life long resilience to stress? And how?
Mild to moderate early life stressors. Enhanced HPA regulation (they can deal with cortisol system better)
How does chronic stress affect normal circadian rhythm of cortisol release?
Increased baseline
How does current life stress affect HPA and what are 2 results of this?
Make HPA axis more sensitive (more release); 1. Higher cortisol exposure, 2. Greater burden after each stress episode
What was found in the Romanian orphan study? 2
- Blunted SAM & HPA responses to lab stressors
2. Normal response if removed from orphanage before 2 years (critical period for effects)
chronic stress disorders that can result from mobilising energy stores? 4
Metabolic dysfunction, II diabetes, inefficient energy use, muscle wasting
Chronic stress disorders from increased blood supply?
Stress hypertension, atherosclerosis, heart disease
Chronic stress disorders from enhanced cognition?
Memory loss, disconnection of neural networks, reduced neurogenesis, selective neurodegeneration
Chronic stress disorders from enhanced immunity, reduced inflammation?
Increased risk of some infectious diseases
Is there an increased rick of cancer due to chronic stress?
Probably not
What is the mechanism which relates chronic stress and anxiety?
Long term enhanced cognition (due to chronic stress response) leads to amygdala expansion
What mechanism relates chronic stress with depression?
Long term stress activation leads to depletion of dopamine, which causes anhedonia
What are the chronic stress disorders associated with the adaptive suppression of growth?
Osteoporosis, osteoarthritis, psychogenic dwarfism
Chronic disorders due to suppression of digestion?
Increased risk of ulcers, increased fat deposition
Chronic disorders due to suppression of reproduction in stress response?
Females - irregular or loss of cycles, failure of implantation
Males - decreased testosterone, erectile dysfunction
Everyone - loss of libido
What causes psychosocial short stature? And what is it? Can it be reversed? 2
Extreme stress and emotional deprivation in childhood causes a failure to grow despite adequate nutrition. Yes the child will catch up after leaving negative environment, but only within a critical period.
Where does cortisol result in structural remodelling? 3 is it reversible?
Hippocampus, amygdala, PFC. yes but more difficult with age.
How does the hippocampus aid the stress response? How does this function integrate with the Amygdala?
Stores contextual info about circumstances where stress response was previously activated, it contributes to the threat appraisal in amygdala.
What happens to stress response if there is damage to HC (from cortisol)?
Loss of regulation, HC is part of system that tells HT to turn off cortisol
What happens to the amygdala under chronic stress? How? 2. What does this mean?
It grows. 1. Increase plasticity and 2. expansion of dendritic processes. Bias towards being more readily afraid and less able to detect safety (anxiety disorder)
What area of the brain mediates defensive behaviours and physiological responses to danger?
The amygdala
Which area provides top-down control of emotional responses and can restrain the amygdala?
PFC
what happens to medial PFC due chronic stress? [3]
Cortisol causes dendritic shrinking, resulting in impaired cognitive flexibility.
What happens in the orbitofrontal cortex in chronic stress? [3] (what is the OFC involved in?)
Cortisol causes dendritic expansion, resulting in increased vigilance to possible new stressors (salience of reward or punishment)
What does cortisol damage to PFC result in?
Impaired amygdala restraint during stress.
How does the PSNS dampen the stress response? 2pathways
Direct inner action of organs (acetylcholine)
Hormones sent to adrenal vortices which suppress cortisol
Is there a bias in SNS vs PSNS?
Yes more biased towards being stress (adaptive). Can require conscious effort to initiate relaxation response
How can relaxation response be triggered?
Deep abdominal breathing, focus on word, visualisation, yoga etc
Why is amygdala threat appraisal negatively biased?
Missing a real threat is worse than misinterpreting something non-threatening
What are differences in PFC inhibition of amygdala for moderate vs intense stress?
Moderate - regulation possible
Intense - restraint is suppressed, not as effective (hijacking)
How can cognitive reinterpretation work? 2
Deciding how to feel about the physiological response which is already kick started:
Threatening or exciting?
Overwhelming or challenging?
What are the limits of cognitive reinterpretations?
Have to deal with the current situation not ignore it, (try to go from fear to calm)
What hormone is associated with social affiliation? What can it do for stress?
Oxcytosin. It can reduce cortisol and suppress HPA axis
What characterises a good social bond?
Supportiveness. Unsupportive contacts can increase stress
What is the danger of being socially isolated? [4]
Isolation is stressful, and this is difficult to manage without support. Unmanaged support becomes chronic which impairs systems that deal with stress, leading to downwards cycle.
What is the risk of mortality for social isolation?
Increases by 26%
Does the amygdala receive sensory input that is direct or indirect?
Both, from thalami nuclei or from cortical areas
Why does the amygdala have HC inputs?
Help mediate learning about context of fear related events
What type of fear context is the HC most sensitive to?
Location
What is mediated by the PAG, in amygdala based fear circuitry?
Defensive or behavioural responses
how does the amygdala activate physiological changes in response to fear?
Output to hypothalamus for SAM/HPA responses
What cognitive functions does the amygdala assist with? 4
Attention, perception, memory, decision making
How is anxiety different to fear?
It is longer lasting and focuses on preparedness.
How is anxiety adaptive?
Motivates effective coping behaviours
When is anxiety a disorder? 2
If it persists or is out of proportion to the threat
What is GAD? 3
Stress and anxiety in absence of obvious cause
Chronic worry and vigilance not warranted by situation
Heightened SNS arousal and motor tensions
What is phobic anxiety disorder?
Intense excessive feat triggered by specific object/situation
What is panic anxiety disorder?
Rapid onset of extreme fear and severe stress symptoms
Which class of anxiety disorder do you find somatic symptoms alongside intense fear?
In a panic attack, panic
Can someone with OCD resist their compulsive behaviour?
Resisting lead as to high anxiety. These behaviour are intended to neutralise negative thoughts.
What is PTSD?
Persistent pattern of distress following an extreme stress event.
In which class of anxiety disorders would you find hyperarousal or an exaggerated startle response?
PTSD
How can PTSD affect the everyday experience of emotions?
Numbness to ordinary stimuli
Which two areas are implicated in anxiety from functional imaging studies?
Amygdala and ACC
What features can distinguish normal sadness from depression? 4
Severity
Pervasiveness
Duration
Associated symptoms
What is monoamine theory in depression?
Depression is caused by underactivity at serotonergic and noradrenergic synapses
What evidence supports the monoamine theory of depression? 2
Treatment drugs are agonists of serotonin or norepinephrine Monoamine antagonist (reserpine) cause depression
What causes what, depression and anxiety?
Who knows
What is an effect of antidepressants on the brain?
Neurogenesis
What is a genetic stress model?
genetic susceptibility plus early stress sensitises the system to overreact to mild stressors
