It's easy to think of depression as an extreme version of sadness, but they actually are distinct emotional states. Sadness is a natural reaction to certain life events. We need to feel sad sometimes, it's part of what makes us human & our lives meaningful. Depression is a state of dysfunction that requires help to get out of. It may or may not be triggered by a real-life situation. And it may or may not include sadness. Some people who are depressed don't report feeling sad, rather they simply feel nothing at all - numb & empty.