A clinical sign of mania is

Mania this disorder tends to occur in episodes which last 3-4months, followed by complete recovery. There is a flight of ideas(rapidly produced speech with abrupt shifts from topic to topic, using external environmental cues. Typically the connections between the shifts are apparent). When the flight becomes severe, incoherence may occur. A less severe and a more ordered flight in the absence of pressure of speech is called prolixity (Ref: a sho textbook of psychiatry, Niraj Ahuja, 7th edition,p g no.70)