When people talk incessantly without making any sense, it is often called psycho-babbles. There are many synonyms for this term, including gibberish, nonsense, drivel, twaddle, balderdash, and claptrap. All of these terms imply that what is being said is not only pointless but also difficult to understand.
Other similar phrases include "word salad," "verbal diarrhea," and "mental clutter." These terms imply a lack of control over one's thoughts and language, as well as a lack of coherence in one's speech. Whatever term is used, the underlying idea is the same: excessive talking without any substantive content is a sign of confusion and disorientation.