What psychiatric condition is characterized by not being able to speak straight forwardly, like with 12 asides before the sentence is finished & fast?

Tangential assoc?: It's not clear, but it sounds like you might be referring to tangential associations -- or what might be described that way in a mental status exam. Psychotic disorders like schizophrenia and schizo-affective disorder are possible, as well as other problems like severe ocd, etc. The person needs a full evaluation by a psychiatrist to determine the nature of this problem.

OCD or bipolar: If you talk around a topic and can't get to the point it is likely ocd or oc personality disorder. If it involves going off on a tangent at fast speed like a pin--ball machine ball bouncing around then it would be bipolar or what has been described as the hyperthymic personality....Like a fast- paced auctioneer. Best wishes.