Besides that cluttering and stuttering can occur simultaneously in one patient, the differential diagnosis between the two disorders is complicated by the fact that they share a number of symptoms. For example, repetitions, interjections and tachylaly (speaking too fast) can be found in both cluttering and stuttering. However, there are also clear differences between the two disorders. The main difference is undoubtedly that the person who clutters seems, to a certain extent, to be oblivious to the glitches in his speech, and is in no way, or far less, concerned about them. While the stutterer is painfully aware of his problem and would do anything to hide it, the clutterer just talks on without worrying too much. So, in what other ways do clutterers seem to differ from stutterers? Former scientist and speech-language therapist Deso Weiss put together an overview based on dozens of years of clinical experience, which he used in diagnosing cluttering.