No joy in life. Walking around going through the motions without any passion or feeling towards life.

Not sure TBH. How about the desire to sleep all the time in order to escape from reality? Also procrastinating too much because you don't have any motivations to start doing what you're supposed to do. I've been experiencing these things recently. I feel I need to talk to a therapist or something.

Depends on the person— might be insomnia, lack of appetite, oversleeping…

when people start giving away their dumb robot that they spent hours disassembling and reassembling and writing buggy code than has them ignoring voice commands and slamming into walls and I'm pretty sure it gave me the finger once and what were we talking about again? 🤪

Everything just starts to go numb... success...eh... food...eh.... sex...eh... then before you know it, you're in bed, not motivated to leave it.

Sleeping all the time, having no interests

Farting during Green Acre reruns 😡

You don't do anything. Literally.

lack of sleep, lack of tension, lack of interest, tiredness, sad face, hectic activities, losing social contact.
But there is no single tell tale sign. Some people are even aggressive while suffering from an extreme episode of depression! Some become also auto aggressive. I should know, I did suffer from depression several years.