What's the difference between "major depression" and "bipolar disorder"?

What's the difference between "major depression" and "bipolar disorder"?

Christopher Reist (Academic Psychiatrist, Co-Author of “Psychiatry”) gives expert video advice on: What's the difference between "major depression" and "bipolar disorder"?; Is there anything I can do to avoid developing bipolar disorder? and more...

Sometimes, when people talk about bipolar disorder, they also use the term "manic depression." Manic depression refers to the observation that individuals with this illness have episodes of both depression and mania - or hypomania - which are two states of elevated mood. Depression, when we use it in the diagnosis of major depression, refers to an illness where you only have episodes of depression, rather than the mania experienced by bipolar sufferers.