What is "pressure of speech"

n. (context psychology psychiatry English) a proclivity to speak with rapidity and intensity without apparent motivation, commonly seen as a marker for a manic episode of bipolar disorder

Pressure of speech is a tendency to speak rapidly and frenziedly, as if motivated by an urgency not apparent to the listener. The speech produced, sometimes called pressured speech, is difficult to interrupt.

It may be too fast, or too tangential for the listener to understand. It is an example of cluttered speech. It can be unrelenting, loud and without pauses.