Week 16 - Risk Factors And Studying Depression Flashcards
What is meant by the term odds ratio?
The statistical measure of association between an outcome and an event
What does an odds ratio represent?
The odds that an outcome will occur given a specific event compared with the odds of the outcome occurring in the absence of the event
What does a higher odds ratio represent?
A stronger association between the event and the outcome
What is meant by the term chronic stress?
A situation caused by repeated and/or prolonged exposure to negative stimuli that results in continuous activation of the body’s stress response
Why did stress responses evolve?
To help animals respond quickly to dangerous situations such as being chased by a predator
What body systems can stress have an impact on?
- Immune system
- Digestive system
- Cardiovascular system
- Nervous system
Where in the body is the adrenal cortex found?
Near the kidney
What are the structures of the HPA axis?
- Hypothalamus
- Pituitary gland
- Adrenal gland
What parts of the brain does the HPA axis have important links to?
- Amygdala
- Hippocampus
- Prefrontal cortex
Which hormone is released from the hypothalamus as part of the HPA axis?
Corticotropin-releasing factor
Cortisol attaches to what type of receptors?
Glucocorticoid receptors
Cortisol acts via glucocorticoid receptors to inhibit activity of the HPA axis so that less cortisol is secreted. Why does cortisol become less effective in inhibiting the HPA axis during chronic stress?
Because high levels of cortisol are present during chronic stress
What is meant by the term early-life stress?
Significant traumatic experiences that occur in childhood. It is a risk factor for depression in later life
What is early life stress a risk factor for?
Depression in later life
Women who have been abused in childhood are how many times more likely to be diagnosed with major depressive disorder in adulthood?
Four times
What is dexamethasone?
A synthetic glucocorticoid that activates glucocorticoid receptors
What effect does dexamethasone have on the activity of the HPA axis?
It inhibits activity of the HPA axis
What are the three components of Beck’s “cognitive theory of depression”?
- Cognitive bias
- Negative self-schema
- The negative triad
What is meant by the term cognitive bias?
The tendency to focus on particular aspects of a situation in a systematic way which can lead to errors in judgement or decision-making
What are the negative consequences of cognitive bias?
It may lead to errors in judgement or decision-making
What is meant by the term negative self-schema?
A person’s set of negative beliefs and assumptions about themselves which can lead to them interpreting situations in a negative way
What are the potential negative consequences of a negative self-schema?
A person will have negative beliefs and assumptions about themself, which could lead to them interpreting situations in a negative way
Which theory posited that people prone to depression may develop a negative self-schema?
Beck’s cognitive theory of depression
What is meant by the term negative triad?
A set of interlinked negative assumptions about the world, oneself and the future
What are the three things which a negative self-triad will cause negative assumptions regarding?
- The world
- Oneself
- The future
What is the theory behind Beck’s cognitive theory of depression?
It posits that distorted thoughts and beliefs about oneself, the world and the future contribute to the development and maintenance of depressive symptoms
What are four personality traits which are particularly associated with depression?
- Neuroticism
- Rumination
- Self-criticism
- Dependency
What is meant by the term neuroticism?
The tendency to be emotionally unstable and to experience negative emotions
What is meant by the term rumination (with regards to mental health)?
The tendency to dwell on negative thoughts which can have a negative impact on mood
What is meant by the term self-criticism (with particular regard to mental health)?
An inclination towards feelings of guilt as a result of high expectations for oneself
What is meant by the term dependency (in the context of mental health)?
An inclination towards feelings of helplessness resulting from a reliance on relationships
What characteristics of depression might it be possible to reproduce in animal models?
- Alterations in eating patterns
- Alterations in sleeping patterns
- Anhedonia
- Helplessness
What is meant by the term mini-brains?
A structure grown in a laboratory from stem cells
Why are mini-brains useful?
They allow us to mimic certain aspects of the structure and function of the brain for research purposes
Can mini-brains produce spontaneous electrical activity?
Yes!
What are some practical reasons which mean it is not possible to develop a perfect animal model for depression?
- Causative factors in humans are not completely understood
- Some factors cannot be reproduced in animals (eg psychosocial factors)
- Some symptoms cannot be measured in animals
With regards to research methods, what is meant by the term internal validity?
How well a study or experiment is designed and conducted
With regards to research methods, how is internal validity achieved?
If all variables that could influence the outcome, other than the one being studied/manipulated, have been controlled
With regards to research methods, what is meant by the term external validity?
The relevance of a study or experiment’s results to other people and situations beyond the scope of the study
With regards to research methods, what is meant by the term reliability?
The extent to which an evaluation or measuring procedure yields the same results or leads to the same conclusions when performed by different researchers
If a measurement is reliable, does that automatically mean it is also valid?
No
Establishing the validity of animal models requires the consideration of which types of validity?
- Face validity
- Predictive validity
- Construct validity
What is meant by the term aetiology?
The causes or origin of a disorder or condition, or the factors that predispose towards a disorder or condition
What techniques could be used to investigate the neuroanatomical basis of depression?
- Neuroimaging techniques such as PET, EEG or MRI/fMRI
- Post-mortem studies
Data from the UK Biobank imaging study has shown what difference to the white matter in brains of people with depression?
White matter integrity is reduced in people experiencing major depression
