Which term describes sudden interruption of thought?

• A. Blocking
• B. Derailment
• C. Thought content
• D. Obsessions

Answer: (A)

Blocking is a sudden interruption in the flow of thought, where the person stops speaking abruptly mid-sentence and cannot recall or continue the intended thought. In the mental status exam, this reflects a disruption in thought process rather than a loss of consciousness or a shift in topic. This differs from derailment, which involves a rapid, inappropriate jump to unrelated ideas; thought content refers to what a person is thinking about (like delusions or obsessions), whereas obsessions are persistent, intrusive thoughts. Because blocking specifically describes an abrupt halt in thought rather than a change in topic or the nature of the thoughts themselves, it is the term that best fits “sudden interruption of thought.”