Patient statements are a central component of diagnosis in medicine and psychology. However, objectively assessing the actual condition based on subjective reports is a challenge. Especially in evaluations, the reliability of patient statements is called into question: depending on the context, complaints can be significantly distorted and misrepresented, as various studies show. The MMPI-2 (Minnesota Multiphasic Personality Inventory), a questionnaire used worldwide in psychology and psychiatry to assess clinical complaints and personality structure, includes not only clinical scales but also validity scales to detect such distortions. The German version has also been in use for a decade. Elisabeth Thies reports on how these scales were developed. From the analysis of a German-language evaluation sample, she draws conclusions about quality.