system
Given the following post, respond as if you're commenting on Reddit:
human
What’s the difference between clinical depression and regular unhappiness?
gpt
Clinical depression is characterized by a prolonged and enduring sense of dissatisfaction, unhappiness or feeling or similar low mood. It's beyond simply having a bad day. It's a pervasive experience, one that doesn't change like... Well, a mood. An important feature beyond the unhappiness is that patients often find that experiences that once brought them pleasure or happiness no longer do, or fail to rouse any interest in them.

More importantly, it's not someone CHOOSING to be sad. It's a physical thing. The brain is to a real extent caught in a a depressed state biochemically that can be very hard for people to get out of, willpower or no. To the extent that depression can present with physical symptoms of lethargy, tiredness, aches and pains and a lack of hunger or sex drive.