What are the 2 major types of depression?
- Unipolar depression: Single or recurrent episodes of depression only.
- Bipolar depression: Episodes of depression with episodes of mania.
What is the occurrence of depression across different genders?
- Unipolar depression: More common in females (2:1 ratio compared to males)
- Bipolar depression: Equal gender distribution
What are the psychological symptoms of depression?
- Sad mood
- Worry
- Negative perception of self and life
- Concentration difficulties
- Suicidal thoughts
What are the biological symptoms of depression?
- Insomnia/excess sleep
- Weight gain/loss
- Loss of sex drive
- Motor changes (slow/fast movements)
- Lack of energy
What are the behavioural symptoms of depression?
- Anhedonia (inability to feel pleasure)
- Slow speech
- Excess crying
- Constant complaining
- Seeking help
- Hypochondria (anxiety about being ill)
What are the symptoms of mania?
- Heightened self-esteem
- Talkativeness
- Lack of concentration
- Increase in motivation
- Too little sleep
- More risk taking
- More ideas
What are the types of bipolar depression?
- Bipolar I: Episodes of mania >7 days
- Bipolar II (hypomania): Episodes of mania 3 - 7 days
What are possible causes for decreasing age of onset for depression?
- Loss of family support (e.g. due to university)
- Fewer/less stable marriages
What are the genetic aspects of depression?
- Unipolar depression is slightly heritable (~30-50%)
- Bipolar depression is highly heritable (~80%)
- Several genes have been implicated as to having small effects
What is the psychoanalytic theory of depression?
- Susceptibility to depression is caused by loss in early childhood, and is triggered later in life by similar loss.
- Loss of parent before age of 11 is major risk factor for depression
What are the types of losses that can be exprienced according to the psychoanalytic theory of depression?
- Actual loss: Loss of loved one
- Symbolic loss: Loss of job, possession…
What is the ‘cognitive theory’ of depression?
- Negative self schema: Negative life event
- Cognitive bias: Greater bias for processing negative information
- Negative triad: Negative thinking
What is the negative triad?
- Self
- World
- Future
What is the evidence for negative cognitive bias?
Patients suffering from depression show:
- Enhanced ability to remember negative events.
- Slower reaction time towards positive stimuli compared to negative ones
What is the ‘absence of positive bias’ theory of depression?
- Instead of having a bias towards negative thinking, depressed patients have a lack of positive bias displayed by non-depressed individuals.
- Positive bias is the tendency to think that a negative event is less likely to happen to oneself despite prevalence suggesting probability is high.
- Depressed individuals have a more realistic outlook on the world.
What are risk factors for depression?
- Negative life event: Experience of loss
- Challenging family dynamics: Lack of support
- Early childhood abuse
- Neuroendocrine factors
- Neurobiological factors
How does early childhood abuse predispose to depression?
- Early childhood abuse leads to excess stress during childhood.
- Stress causes dysregulation of the HPA axis which causes increased cortisol release to later stressors.
- Increased release of cortisol predisposes to depression.
What are the neuroendocrine factors predisposing to depression?
Elevated levels of stress hormone cortisol
Which areas of the brain are involved in depression?
- Lower activity in prefrontal cortex of depressed patients compared to normal patients when shown positive words
- Higher activity in amygdala of depressed patients compared to normal patients when shown negative words
- Reduced activity in subgenual cingulate cortex (diminished in depressive episodes and elevated in manic episodes)
What are the treatments for depression?
- Monoamin oxidase (MAO) inhibitors: Inhibits breakdown of 5-HT
- Selective serotonin reuptake inhibitors (SSRIs): Inhibits reuptake of sertonin
What is the mechanism behind action of anti-depressants?
Upregulation of 5-HT activity in the brain
What is the serotonin hypothesis of depression?
Depression is caused by low levels of serotonin activity in the brain
What are the problems with the serotonin hypothesis of depression?
- Anti-depressants elevate 5-HT levels immediately, but their anti-depressive effects only take action after ~1 month.
- 5-HT based antidepressants don’t work on all patients with depression.
- Invalid to assume that just because anti-depressants work by increasing levels of serotonin, low levels of serotonin cause depression.
What are non-pharmacological treatments for depression?
- Cognitive-based therapy (CBT): Psychiatrist discusses problems with patients and give them coping strategies.
- Self-remission: Depression goes away by itself.
- Electroconvulsive therapy: Small electric currents are passed through brain to trigger seizure.
- Surgery: E.g. deep brain stimulation, stimulating parts of the brain that are underactive in depression with electrode.
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Introduction to psychology14
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Cognitive neuroscience of memory45
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Attention28
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Neurobiology of Memory27
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Neural basis of language19
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Language across the adult lifespan21
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Judgment and decision-making15
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Neural basis of planning and action26
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Developmental cognitive neuroscience25
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Intelligence and IQ testing20
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Schizophrenia32
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Depression26
