system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: Why does short-term sleep deprivation alleviate depression while chronic sleep deprivation seems to worsen it?
gpt
Short term sleep deprivation (a type of stress) increases the stress hormones cortisol and adrenaline, which in the short term, make you feel buoyant and happy. 

Chronic sleep deprivation, with chronic increase in stress hormones cortisol and adrenaline give rise to depression.