The Latent Structure of Acute Stress Disorder: A Posttraumatic Stress Disorder Approach

Acute stress disorder (ASD) was first included in the Diagnostic and Statistical Manual of Mental Disorders (4th ed.; DSM-IV; American Psychiatric Association, 1994) to account for the psychological symptoms present during the one-month period between trauma exposure and a posttraumatic stress disorder (PTSD) diagnosis. The diagnostic criteria sets of both ASD and PTSD are similar; however, ASD includes additional dissociative items. Factor analytic research into ASD is rare, whereas there is a plethora of research on the factor structure of PTSD symptoms. This study tested whether the latent structure of ASD is similar to the latent structure of PTSD. Five models were tested by using data from Danish rape victims (N = 380); a unidimensional model, the DSM-IV 4-factor ASD model, a King, Leskin, King, and Weathers (1998) replication model, a Simms, Watson, and Doebbeling (2002) replication model, and a 3-factor model. Model fit was assessed by using a number of fit indices, including the root-mean-square error of approximation, comparative fit index, Tucker-Lewis index, and standardized root-mean-square residual. However, based on the fit indices, 3 models were deemed indistinguishable. Chi-square difference tests concluded that a 3-factor model and two 4-factor models did not differ in fit. Overall, the current 4-factor ASD latent structure proposed by the DSM-IV was not supported. A 3-factor structure was deemed preferential on the basis of parsimony. Furthermore, of all models, the unidimensional model provided the poorest fit to the data. These findings are pertinent given that the DSM-5 ASD task force is considering implementing either a 4-factor conceptualization or a unidimensional approach to the ASD diagnosis.