Dimensional latent structure of PTSD-symptoms reporting: Is it adding by subtracting?

Although posttraumatic stress disorder (PTSD) is used as a distinct diagnosis in clinical practice, its symptoms were characterized as a dimensional structure in several taxometric analyses. However, a categorical latent structure of PTSD could be superimposed by using indistinct PTSD symptoms that can appear within the framework of other trauma-induced syndromes (e.g., depression, anxiety disorders). For that reason, in revising the International Classification of Diseases (ICD-11), a core set of cardinal symptoms that determine the presence of PTSD as selectively as possible will be used. To determine whether the latent status of a recommended core set of PTSD symptoms is dimensional, the authors analyzed the latent status of PTSD symptoms reported by participants who had experienced at least 1 traumatic event during their lifetime in 2 nationwide surveys of the German population (N = 1,212). Using the Posttraumatic Diagnostic Scale (PDS), they applied 3 popular taxometric methods: maximum eigenvalue, mean above minus below a cut, and latent mode factor analysis, using the core set and PTSD symptom clusters of previous taxometric studies. Although the analysis replicated findings of previous taxometric analyses using symptom clusters, the item core-set approach indicated a categorical solution of PTSD cardinal symptoms. These results seem to support the procedure used by the ICD-11 expert group. (PsycINFO Database Record