Hilfe und Information in der Ulmer Onlineklinik | Accessed Online January 2019. | The <span class="attribute-to-highlight medbox">CATS</span> questionnaire is a short freely accessible screening instrument directly based on the DSM-5 criteria for Posttraumatic Stress Disorder (PTSD). It is a measure of potentially traumatic events <span class="attribute-to-highlight medbox">and</span> of posttraumatic stress symptoms.