This was my thing too. Turns out I wasn't necessarily depressed. I had executive functioning issues so I couldn't start anything. Things weren't fun because I knew I'd have to bully myself into getting started. I laid in bed all day on my days off not because I was depressed but, because of task paralysis. And turns out when life is just too hard to do anything other than the bare minimum, it can make you depressed. Who knew?!