First let's look into the symptoms that might lead to a diagnosis of bipolar mania.
A Sample Case of a Manic EpisodeLarry was a young man who had become hyper-energetic, needing only three or four hours of sleep a night to be full of vim and vigor the next day (decreased need for sleep). He seemed to be feeling exhilarated all the time (persistent elevated mood). His friends and family weren't particularly worried at this point, but when he started running up thousands of dollars on all his credit cards, buying expensive clothing and furniture he didn't have room for, and knickknacks that were not to his normal taste at all (risky behavior), they were worried and tried unsuccessfully to reason with him. Then, when he started jumping from topic to unrelated topic while talking (flight of ideas), and confided to his family that he was really the King of Somalia and was making plans to take over that country (delusions), a couple of them took him to the emergency room, where a manic episode was diagnosed based on his family members' reports and his own behavior.
See What Is Mania? for the list of diagnostic symptoms of a manic episode.
Manic Doesn't Mean ManiacExperiencing bipolar mania does not automatically mean that a person will be violent or dangerous. Yes, this can happen. A particular cluster of symptoms might make a person a reckless and dangerous driver. Delusions and hostility could cause someone to write threatening letters or publish lies about another person on the Internet. Hallucinations and/or delusions could lead someone to jump off a roof, start a fire or attack another person. It all depends not only on which symptoms are present, but also on what form they take.
And indeed, studies have found that people with severe mental illnesses are actually twice as likely to be victims of violence than the general population.
The fact is that the vast majority of people who experience mania never cause physical harm to anyone. On the other hand, manic symptoms can, and all too often do, lead to financial hardship, wrecked relationships, job loss and other events that can have disastrous long-term effects. Mania needs to be treated to minimize potentially devastating consequences.