Depression is often associated with chemical imbalances in the brain. This may be traced back to certain neurotransmitters like serotonin, which play a significant role in producing depressive symptoms.

Real-world example: Imagine serotonin as a crucial team player in a football match. If this player isn't performing well (low levels of serotonin), the entire team (our brain) could lose the game (fall into depression).

Antidepressants are drugs designed to target and adjust these imbalances. They aim to restore the balance of neurotransmitters, thereby reducing depression symptoms.

The name 'tricyclic' comes from the chemical structure of these drugs, which contain three rings of atoms. TCAs work by inhibiting the reuptake of certain neurotransmitters, like serotonin and norepinephrine, after they are released in the synaptic gap, thus increasing their concentration.

Fun fact: The depression-reducing effect of TCAs was discovered completely by accident!

Real-world example: Think of neurotransmitters as cars on a highway (synaptic gap). TCAs act as traffic controllers, keeping the cars on the road for longer (preventing reuptake), which increases the traffic (concentration of neurotransmitters).

However, TCAs have been largely replaced by newer drugs due to their potentially severe side effects such as weight gain, dizziness, and risk of fatal overdose.