Epidemiology - Depression and bipolar Flashcards
Recurrent depressive disorder occurs in what % of males and females? The usual age of onset is?
10-25% of women and 5-12% of men. It is twice as common in females than males (2:1)The usual age of onset is late 20s.
What % of the population does bipolar disorder occur in? What is its age of onset and the variation between M and F
Bipolar affective disorder occurs in 1% of the population. Average age of onset is 20 and there is no variation in incidence between M and F
What % of the population does cyclothymia occur in? What is its average age of onset? is there a difference between M and F incidence
0.5-1%, average age of onset is adolescence or early adulthood. No difference in incidence between M and F
Dystthymia. Incidence, Average age on onset, Male to female ration
3-6% of the population. Average age of onset is childhood, adolescence or early adulthood. F:M = 2-3 : 1
Aetiology of depression.
What is the monoamine theory?
How is the hypothalamic pituitary axis thought to be involved?
IS there a genetic element to depression?
Monoamine theory; depression is due to a shortage of noradrenaline, serotonin and possible serotonin. Its likely that GABA and various other peptides are involved
Risk factors of depression?
Vulnerability factors in women?
Families showing high expressed emotion and criticism have been shown to increase the relapse of depression.
-Certain personality disorders
-Adverse life events; divorce job loss, bereavement
Vulnerability factors in women: 3 or more children at home under the age of 14, not working outside the home, lack of a confiding relationship, loss of mother before the age of 11
Prognosis of depression
Without treatment how long does a 1st depressive episode take to remit?
What % relapse?
What is the risk of a pt with depression committing suicide compared to the general population
- 6-12 months
- Depression is chronic and relapsing at least 60% of pts have a further depressive episode. The risk of future episodes increases with each relapse
- Depression is one of the most important RFs for suicide, rates are 20x greater than those in the general population
Aetiology - Bipolar
How does the monoamine theory apply to depression?
What is the evidence for there being a genetic component to bipolar affective disorder (concordance rates in monozygotic twins ect)?
Are any personality traits strongly associated with the development of bipolar affective disorder?
What can provoke the 1st manic or hypomanic episodes?
- Monoamine theory for depression is also applicable to elevated mood. Manic episodes are thought to be due to an increased central noradrenaline or serotonin level
- There is strong evidence for a genetic component with a concordance rate of 65-75% in monozygotic twins compared to 14% in dizygotic twins
- There are no personality traits associated with the development of bipolar
- Significant life events and stress can provoke the 1st manic episode
Prognosis - Bipolar
- What % of pts go on to suffer further epsiodes after a single manic episode?
- What is the frequency of these episodes?
- What % of pts have 4 or more episodes a year and what is this termed
- What % successfully complete suicide
- 90% have further episodes
- Average frequency of episodes is 4 in 10 years
- 5-15% this is termed rapid cycling and is associated with a poor prognosis
- 10-15% of pts successfully complete suicide
Dyshmia and cyclothymia
- Describe the onset and course of both conditions
- Average age of onset?
- What do a significant number of pts with cyclothymia go onto develop?
- What can dysthymia coexist with?
- Both conditions have an Insidious onset and chronic course
- Often begin in childhood or adolescence
- Sig number of pts with cyclothymia suffer from severe affective disorders, most likely bipolar affective disorder
- Dysthymia can coexist with depression (double depression), anxiety disorders and borderline personality disorders
What are feelings and mood?
Feelings are short lived emotional states
Mood is a pts sustained subjectively experienced state of emotion over a period of time.
What are the cognitive symptoms of depression
Thoughts that the pt has about themselves and the world as well as global brain functioning
- Reduced concentration and attention
- Poor self esteem
- Guilt - about past minor failings
- Hopelessness
What are the biological symptoms of depression
If a pt has 4 or more of the following symptoms it can be coded for in the ICD-10:
- Loss of interest or pleasure in activities they normally find enjoyable (anhedonia)
- Reduced emotional reactivity
- Early morning waking
- Depression worse in the morning
- Psychomotor retardation or agitation
- Marked loss of appetite
- Weight loss of 5% in the past month
- Loss of libido
Psychomotor and severe motor symptoms
-What may pts suffer from in severe depressive symptoms?
Delusions, hallucinations, or a depressive stupor; these are termed psychotic symptoms. Delusion and hallucinations are most often be mood congruent but can be mood incongruent. So often take the form of criticising voices or the smell of rotting flesh.
- Stupor is an extreme unresponsiveness and lack of voluntary movement that can border on mutism
- Severe motor symptoms are more common in schizophrenia and bipolar affective disorders but can occur in unipolar depression.
ICD-10 for depressive episodes
what are the Core symptoms? how many need to be present?
What are the other symptoms?
Core symptoms At least 2 of the following are needed -Depressed mood -Loss of interest and enjoyment -Reduced energy or increased fatigability
At least 2 of the following are also needed
- Reduced concentration and attention
- Reduced self esteem and self confidence
- Ideas of guilt and worthlessness
- Bleak and pessimistic views of the future
- Ideas or acts of self harm or suicide
- Disturbed sleep
- Diminished appetite
