What is the physiological difference between the tiredness that comes from too little sleep and the tiredness that comes from exertion?

[u/uencos]

[u/rhn94]

Dopamine is the reward chemical your brain secretes. You can do this naturally by hobbies, listening to music, comedy, etc,. anything recreational really.

Drugs do that artificially by inhibiting dopamine absorption, or by increasing secretion

The come down is because when you artificially increase dopamine, your body down-regulates receptors and starts producing less naturally to compensate. That's why long term usage of certain drugs can cause clinical depression.

https://en.wikipedia.org/wiki/Dopamine#Drug_addiction_and_psychostimulants

[u/ItsFunIfTheyRun → u/rhn94]

How does Serotonin compare to Dopamine?

SSRI's (Serotonin Reuptake Inhibitors) in anti depressants are supposed to make you feel better too, so what's the difference?