A common -- but mistaken -- belief is that there is only one type of bipolar disorder, but there are actually several:
- Bipolar I disorder is distinguished by its inclusion of a full-blown manic episode at some point in the person's life.
- A person with bipolar II, a milder form of the disorder than bipolar I, goes back and forth between periods of depression and periods of elevated moods, but not actual mania.
- Cyclothymic bipolar disorder is similar to bipolar II, but less severe.
- Several periods of mania and/or depression in a single year indicates rapid cycling bipolar disorder.
- If highs and lows coexist or occur quickly back-to-back, this is mixed bipolar disorder.