From Key Redfield Jamison (born 1946), American clinical psychologist and writer, An Unquiet Mind: A Memoir of Moods and Madness (1995):
Others imply that they know what it is like to be depressed because they have gone through a divorce, lost a job, or broken up with someone. But these experiences carry with them feelings. Depression, instead, is flat, hollow, and unendurable. It is also tiresome. People cannot abide being around you when you are depressed. They might think that they ought to, and they might even try, but you know and they know that you are tedious beyond belief: you are irritable and paranoid and humorless and lifeless and critical and demanding and no reassurance is ever enough. You’re frightened, and you’re frightening, and you’re “not at all like yourself but will be soon,” but you know you won’t.