Fun fact: staying up for 24h+ causes a relief of symptoms in >50% of depressed individuals. However, almost all relapse the moment they sleep again (even if it's a 'micro-sleep').
https://en.wikipedia.org/wiki/Wake_therapy#Response_rate_to_...
https://en.wikipedia.org/wiki/Wake_therapy#Response_rate_to_...
It has some theories on a synapse level and some AI/NN analogues regarding the paradox of "good sleep = good mood" and yet "no sleep = relief" for depressed people.