- Situational: you force yourself to do things, you feel better and break out of the cycle

- Physical: you force yourself to do things, you don't feel anything but suffering. You don't get endorphins from exercise, you don't get serotonin from going to events and hanging out and achieving things. Depression is usually anhedonia which is a loss of feeling - whatever happens you're completely emotionless

Depression creates a feedback loop: not doing things makes you depressed, depression makes you not do things. So sometimes you are just lazy and need to start doing stuff. But sometimes it's a physical depression which caused you to stop doing things, and just doing things again won't make you not depressed. That's why I generally suggest starting and trying things, to see if they have any effect, but don't push it otherwise.