Pathological redundancy refers to the association of the patient’s thinking process is very easy to get away from the central topic, the emergence of extraneous associations, usually indicates that the speaker’s abstract generalization and low comprehension ability, manifested as verbose speech, can not grasp the focus, the thinking process gives the impression of a difficult step, meandering, overly detailed, contains many unnecessary details and irrelevant branch branches. The diagnosis of this symptom is based not only on its symptomatic manifestations, but also requires differential diagnosis with some similar symptoms to avoid misdiagnosis and misdiagnosis. Pathological redundancy needs to be differentiated from the following symptoms: 1. Etiological redundancy: Contrary to pathological redundancy, the statement is too brief. This simple answer is not a reluctance to answer questions, but because the thoughts are empty and the available concepts are reduced, reflecting the inhibition of the patient’s thinking and the paucity of concepts. The patient’s answers are generally relevant, but monotonous and empty, often answering “I don’t know” or “I don’t think anything”. 2, thinking interruption: refers to the patient in the case of clear consciousness, the conversation suddenly interrupted, thinking into a blank, pause a moment to speak again has been replaced by a completely new thinking content. This interruption is not for the sake of refining the wording and another thought, nor is it interrupted by the interference of external stimuli, but a momentary pause in thinking activity for no reason, and its occurrence is involuntary. For patients who still have some self-awareness, this is a horrible experience, the patient feels that the thinking is “sucked away” by external forces, “taken away”, the subjective experience of thinking is taken away, thinking is taken away is only the patient’s delusional interpretation of the interruption of thinking. 3, repetitive speech (palialia): thinking wanders in the same place, does not step forward, in the language is expressed in the thinking activity on the answer to the previous question, the thinking process stagnant, no longer develop, can not be associated with the change of questioning and the formation of new concepts, still repeat the previous answer. If the patient intends to mechanically repeat the question that is not relevant to the current situation for a long time, it is called stereotypeofspeech. The patient’s thinking is short-circuited, and the brain is unable to form new concepts, so the concepts cannot be transformed. This syndrome is also called perseveration. 4, imitation speech (echolalia): refers to the patient imitate the content of the speech of the surrounding people, others say what the patient said, just a mechanical repetition, as if it is a rehash of the content of other people’s speech.