Depression is associated with feelings of sadness, loss of interest, and sleep disturbances. It involves decreased levels of monoamines like serotonin, norepinephrine, and dopamine in the brain. Common antidepressant drug classes include tricyclic antidepressants, selective serotonin reuptake inhibitors (SSRIs), serotonin-norepinephrine reuptake inhibitors (SNRIs), and monoamine oxidase A (MAO-A) inhibitors. Antidepressants work by inhibiting the reuptake or breakdown of neurotransmitters like serotonin and norepinephrine. They are used to treat conditions like depression, anxiety disorders, OCD, and chronic pain.

2.  Depression is a common
clinical condition
associated with feelings of
sadness, loss of interest,
self-neglect, anorexia,
sleep disturbances,
suicidal feelings in severe
cases, etc.

3.  Decrease in levels or functions of
monoamines (5-HT, NE, DA) in cortical and
limbic system
 Decrease in brain-derived neurotrophic
factor (BDNF)
 Abnormalities in thyroid function and sex
steroid levels

4. 1. Tricyclic antidepressants
 Amitriptyline
 Nortriptyline
 Trimipramine
 Imipramine
 Doxepin etc
2. Serotonin and Noradrenaline reuptake inhibitors (SNRIs)
 Duloxetine
 Venlafaxine

5. 3. Selective Serotonin reuptake inhibitors (SSRIs)
 Fluoxetine
 Paroxetine
 Fluvoxamine
 Sertraline etc.
4. MAO-A inhibitors
 Moclobemide
 Clorgyline
5. Atypical antidepressants
 Bupropion
 Mianserin

6.  Inhibit norepinephrine transporter (NET)
enhance the availability of NA at the receptors
in CNS
 Inhibit serotonin transporter (SERT) → block
reuptake
 Muscarinic blockade
 α1- adrenergic blockade
 H1 blockade

7.  Inhibit serotonin transporter (SERT) → block
reuptake → increase availability of 5-HT at
receptors in CNS and enhance serotoninergic
activity
3. Serotonin and Noradrenaline reuptake
inhibitors (SNRIs)
 Inhibit reuptake of serotonin and noradrenaline
into the neuron

8. A. Bupropion
 Inhibits reuptake of DA and NA into the
neuron
B. Mianserin
 Increases NA release by blocking
presynaptic α2 receptors

9.  A selective and reversible inhibitor of MAO-A
(RIMA)
[MAO-A is responsible for mainly metabolism
of NA, 5-HT and tyramine.]

10. 1. Atropine-like side effects [TCA]
2. Insomnia [SSRI]
3. Sexual dysfunction [SSRI,SNRI]
4. Sweating [SNRI]
5. Seizures [Mianserin]

11. 1. Depression
2. Anxiety disorders
3. Obsessive compulsive disorders (OCD)
4. Nocturnal enuresis
5. Prophylaxis of Migraine
6. Chronic pain including Neuralgias
7. Attention deficit hyperactivity disorder