Depression - epidemiology & biological basis Flashcards
What are core features of depression?
- Low mood
- Loss of interest/enjoyment (anhedonia)
- Reduced energy -> fatigueability
Core symptom basically struggling to feel happy
What are the biological symptoms of depression?
- Early morning wakening
- Loss of appetite
- Diurnal variation in mood
- Psychomotor retardation/agitation
- Loss of libido
- Reduced concentration and attention
What are the cognitive symptoms of depression?
- Reduced confidence/low self-esteem
- Worthlessness and guilt
- Helplessness
- Hopeless (pessimistic)
- Thoughts of self-harm/suicide
What constitutes ‘mild’ depression?
- 2 core symptoms + 2 others
- None to an ‘intense degree’
- Distressed + some difficulty continuing with ordinary work / activities
What constitutes ‘moderate’ depression?
- 2 core symptoms + 3/4 others
- Considerable difficulty in continuing social, work or domestic activities
What constitutes ‘severe’ depression?
- 3 core + 4 others with some of ‘severe intensity’
- Unlikely they will be able to continue social, work or domestic activities
- Includes psychosis
What is the prevalence of major depression in (i) primary care and (ii) chronic illness?
(i) 5-10%
(ii) 25%
Are males or females more likely to get depression?
Females have a double risk
What is the mean age of onset for (i) bipolar disorder and (ii) unipolar depressive disorders?
- bipolar - 17 (community) 21 (hospital)
- unipolar - 27
In terms of risk factors, what are internalizing factors? Examples?
- Internalizing factors - things that are directed inside, dealt with internally.
- genetics, neuroticism, low self-esteem, early onset anxiety
These are not visible
In terms of risk factors, what are externalising factors? Examples?
Things focused outside of oneself eg. genetics, substance misuse, conduct disorder
Visible
What are examples of adversity risk factors?
- Trauma during childhood/adulthood
- Stressful life events / year
- Parental loss
- Low parental warmth
- History of divorce
- Marital problems
- Low social support
- Low education
How do genetics influence the aetiology of depression?
A biological factor, evidence that mood disorders are genetically transmitted eg.
- Corticotrophin RHR polymorphisms reduce risk of depression
- Chromosome 3, 10 polymorphisms associated w/ depression
- Calcium signalling pathway polymorphisms
Factors involved other than genetics, twins also share similar psycho-social environments, which could account for high concordance rate.
What is the MA hypothesis?
Most important biological theory - serotonin, noradrenaline and dopamine implicated
- Began as MAOIs and TCAs found to treat depression
- Reduced plasma conc of precursors to 5HT in patients w depression
- Reduced 5HT in PM brains of suicide/depression victims
- Depleting 5HT precursors leads to relapse of depression
- Drugs to deplete NA induce depressive symptoms in recovered depressed patients
- Decreased dopamine metabolites in CSF
What are the features of Beck’s Cognitive Triad?
Negative thoughts about:
- The self - I am to blame
- The world - The world is unfair
- The future - The future is hopeless
