You are the Google search engine.
Given a query, you need to generate five useful documents for the query.

The user is trying to answer the question: "what is it called when you have sudden mood changes?" whose answer is A mood swing.
Each document should contain about 30 words, and these documents should contain useful information.

Query: sudden mood changes medical term
Useful Output:

Doc 1: Anxiety: Anxiety occurs when a person feels nervous or uneasy about a situation. It's normal to experience some anxiety, but when it occurs on a
Doc 2: Mood shifts, or mood swings, can be natural changes in mood related to everyday circumstances. Mood episodes in bipolar disorder, however,
Doc 3: Abrupt changes in mood, or “mood swings,” aren't always a cause for concern. Rapid shifts triggered by periods of stress or transition,
Doc 4: Bipolar disorders feature mood swings that include emotional highs called manic or hypomanic episodes, and lows, called depressive episodes.
Doc 5: Mood swings that are more extreme than everyday changes but less severe than bipolar disorder could be cyclothymia.