Measuring (extrapyramidal) psychotic disorders often is a highly relevant part of clinical research into the course and treatment of movement disorders. Traditionally these disorders have always been assessed on the basis of a well-known set of rating scales. The limitations and shortcomings of these scales are discussed in the article. It is argued that a new standard instrument needs to be developed for the measurement of movement disorders. The sadimod can be regarded as a good starting point for the development of such an instrument.