Which term refers to a train of thought that changes logically from topic to topic but does not return to the initial topic?

The correct term that refers to a train of thought that changes logically from topic to topic but does not return to the initial topic is tangential. This type of thought process is characterized by responses that are related to the original question or topic but drift away, leading the conversation in a new direction without circling back to the point of origin.

Tangential thinking is often observed in various psychiatric conditions and signifies a break from the main focus of a discussion, where the individual may provide information that, while relevant in some sense, does not sufficiently address the original topic. This can lead to a disorganized flow in communication, making it challenging for listeners to follow the speaker's line of thought.

In contrast, perseveration involves the repetition of a particular response or topic, showing a fixation on a specific idea rather than transitioning to others. Thought-blocking refers to a sudden interruption in thought or difficulty in retaining a train of thought, where the individual may abruptly stop speaking or lose the continuity of their ideas. Neologisms are newly created words or expressions that may have personal meaning for the speaker but are not widely understood by others, exemplifying a different aspect of thought disorder. Understanding these distinctions is crucial in psychiatric practice for effective assessment and communication.