Downregulates 5HT, alpha and beta receptors, BUT upregulates cAMP activation--> greater receptor sensitivty = produces a response similar to # of receptors before or a greater magnitude
MAOI's MOA?
inhibits MAO to increase levels of NE and 5HT in presyn term--> more transmitter released
Where do MAOI's work?
presyn. terminal
List the classes of pharmacotherapy for depression
1. MAOI
2. TCA
3. SSRI
4. SNRI
5. 5HT antagonists
6. Atypical Antidepressants
What does the disregulation/low levels of NE and DA contribute to?
anhedonia (lack of pleasurable feeling), decreased energy, memory impairment and executive function deficits.
What do low lvls of 5HT contribute to?
Disregulation of: appetite, sleep, libido, motor function, anxiety and aggression
What are monoamines?
Endogenously synthesized transmitters w/ amine groups. Two groups: catecholamine and indoalmine.
What is the monoamine hypothesis of depression?
It states that patients with depression have low levels of monoamines vs thsoe who don't have depression
What are the 3 components of sleep architecture that is disrupted by depression?
1. Increased time to sleep onset
2. Little time in stage 3 and 4 deep sleep states
3. Decreased REM latency (REM starts earlier)
What symptom is the most prevalent and persistent in depression?
Disruptions in sleep
What is one problem with the dexamethasone challenge?
There is a high rate of false + and -.
Besides measuring cortisol levels and looking for sleep abnormalities, what is another test that can be administered to possibly depressed patients? Describe.
Dexamethasone Challenge. Dexamethasone is a synthetic glucocorticoid that tricks the brain to think it is cortisol, which should cause negative inhibition and reduce cortisol levels. Depressed patients do not suppress cortisol secretion.
True or false. Depressed pt. always has a problem with the HPA gland
False
True or false. Depressed patients have high plasma levels of cortisol
True
What does the increased secretion of cortisol indicate?
A disruption in the hypothalamus-pituitary adrenal axis (HPA-axis)
What occurs in abnormal neuroendocrine function?
Hypersecretion of corticotropin releasing factor (CRF), which causes higher release of cortisol due to increased stress
What % of pt have neuroendocrine abnormalities?
45-60%
What are 2 biological markers for depression?
1. Test for Neuroendocrine function
2. Sleep study to measure abnormality in sleep stages
Describe the criteria for a major depressive episode vs disorder in terms of duration of suffering
An episode is classified as an episode if the episodes occurs are spaced out by a minimum of 2 months.
How many episodes must occur to be diagnosed as a major depressive disorder?
2 or more
How many symptoms must be present to qualify as a major depressive episode
5 or more
what % of the population has had a major depressive episode in their lifetime?
