Sometimes I get depressed for no obvious reason. I know it's because of certain neurotransmitters in my brain that are out of whack, not because of outside circumstances. But my friends and family keep thinking that it's all in my head, and they say stuff like "I should be way more depressed than you, I've been through worse troubles in my life," etc. But I don't usually get depressed because of outside circumstances--it just happens.

Do you find that most people can't grasp the concept of someone being depressed without any specific external cause?