Depression Flashcards
(56 cards)
True/False? Antidepressants are the best-selling drugs on the market
True
True/False? Major depression is an affective disorder
True
Define Monozygotic concordance
The chance of having the same illness if your identical twin has it (confers genetic linkage)
True/False? Depression is not a chronic relapsing disorder
False
After a first episode, almost 70% will have at least one more episode within 5 years
List the 3 different types of major depressive disorder
Reactive depression
- specific stress - responds well to antidepressants
Endogenous (melancholic) depression
- no obvious external cause - often runs in families
Atypical depression (not covered in course)
Where does the term “melancholy” come from?
Melan + choly
black bile
The notion that moods were based off the 4 humors
According to the monoamine hypothesis of depression, what causes depression?
A deficit in monoamine transmission (at certain sites in the brain
How was the monoamine hypothesis of depression founded?
Based on drugs that appeared to relieve and cause depression
What are the monoamines targeted by the monoamine hypothesis of depression?
Noradrenaline, NA
5-hydroxytryptamine (serotonin)
Describe the NA synapse
- Tyrosine is converted to DOPA, which is converted to Dopamine (DA), which is then converted to Noradrenalin (NA)
- NA is the released from the presynaptic neuron and acts on receptors of the postsynaptic neuron and autoreceptors of the presynaptic neuron (-ve feedback)
- NA is then reuptaken into the presynaptic terminal by NAT where it can either be reused, or metabolised by Monoamine Oxidase (MAO)
What is reserpine and what was it reported to do?
Found in snakeroot:
Antihypertensive
Caused depression
Depletes monoamine transmitters
Blocks vesicular monoamine transporter (sends monoamine out of the presynaptic neuron, different from NAT)
What is Iproniazid and what does it do?
Monoamine Oxidase inhibitor: blocks MAO so that more reuptaken NA can be released per vesicle
What is Imipramine and what does it do?
Tricyclic antidepressant:
blocks plasmalemmal NET/NAT, which causes more NT in synapse, which causes more APs at postsynapse
True/False? Imipramine depletes NA
False
What were Axelrod’s 2 experiments, and what were the results?
1) Give normal mouse and SNS-lesioned mice and give labelled NA - accumulation in sympathetic innervation (must be some sort of NA pump)
2) Take same mice and give NA, measure BP - slight increase in intact rat, large increase in denervated rat (no organs to receive NA, all ends up at brain postsynaptic receptors)
What are 2 consequences of inhibiting NA reuptake?
Decreased Recycled NA - less in release vesicles
Increased autoreceptor-mediated inhibition of NA release
True/False? Iproniazid blocks metabolism of NA and 5-HT
True (some MAOIs are more selective)
Name one brand name of fluoxetine
Prozac
What is fluoxetine and what does it do?
Selective Serotonin Reuptake Inhibitor
Blocks SERT more than NET
What does reserpine actually do?
Blocks vesicular pump (not selective for DA/NA/5-HT
What are three facts that support the monoamine hypothesis?
- Low 5-HIAA (5-HT metabolite) in suicide attempters CSF
- Increased 5-HT1A autoreceptors in suicide victims
- Drugs that improve/worsen mood have mechanisms that follow the hypothesis
What are 3 ways to worsen mood?
- Take reserpine (maybe)
- Tryptophan-free diet (only if you’re at risk for depression)
- alpha-methyl-para-tyrosine
What are the three main problems with the monoamine hypothesis?
- not all drugs “agree” with the hypothesis
- Therapeutic effect is delayed
- Logical issue
True/False? Reserpine causes depression
False
The study had small n, uncontrolled trials
