Dimensions and Dissociation in PTSD in the DSM-5: Towards Eight Core Symptoms

The article reviews the literature on the dimensional (factor) structure of posttraumatic stress disorder (PTSD) as presented in the DSM-5 (Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition; American Psychiatric Association, 2013). The DSM-5 PTSD diagnostic category contains 20 symptoms split into four factors. Also, the article considers the literature on the dissociative subtype, which is found in a minority of PTSD cases. The literature shows that the DSM (Diagnostic and Statistical Manual of Mental Disorders) over the years has moved from a three-dimensional structure in prior DSMs to one with four dimensions in the DSM-5. However, the research reviewed queries whether the DSM-5’s four dimensions are consistent with the empirical literature; in this regard, models with five and six dimensions were the first to suggest alternatives. Moreover, in the literature, the DSM-5 symptoms appear to group into as many as seven dimensions, which are as follows: re-experiencing, avoidance, negative affect, anhedonia, externalizing behavior, anxious arousal, and dysphoric arousal (Armour et al., Journal of Psychiatric Research 61: 106–113, 2015; Wang et al., Journal of Anxiety Disorders 31: 90–97, 2015). In particular, the two DSM-5 dimensions of negative alterations in cognitions and mood and alterations in arousal and reactivity appear to be subdivided into five dimensions. Generally, the 20 PTSD symptoms and their suggested factors that are found in the literature could prove unwieldy to clinicians. Moreover, they allow for much heterogeneity in symptom expression among PTSD cases. In response, the article presents a model of PTSD based on the seven-factor dimensional structure emerging in the literature, as well as another factor associated with the dissociation subtype, but with one core or primary symptom specified for each of the dimensions. The article considers forensic implications of the newer models on PTSD’s dimensional structure. © 2015, Springer Science+Business Media New York.