Examining the 4-D Model in Persons Enrolled in the Top DD Internet Intervention

The 4-dimensional (4-D) model of trauma-related dissociation differentiates between dissociative experiences involving trauma-related altered states of consciousness and symptoms of distress that do not appear to involve alterations in normal waking consciousness across four phenomenological dimensions (i.e., our experience of time, thought, body, and emotions). The current study evaluated hypotheses associated with the 4-D model using analyses of variance and correlation analyses in individuals with a primary diagnosis of a trauma-related dissociative disorder who were participating in the TOP DD internet study involving a combination of in-person psychotherapy and an online psychoeducational program (n = 111). Intrusive memories of traumatic events were more frequently endorsed than flashbacks, but emotional numbing was more frequently endorsed than other forms of affect dysregulation. Negative thoughts and emotion dysregulation were more strongly intercorrelated than were voice hearing and emotional numbing. Distress symptoms were more strongly associated with PTSD symptoms and difficulties in emotion regulation, whereas experiences of depersonalization were more strongly associated with dissociative self-states. Greater reduction in distress symptoms was also seen in comparison with trauma-related altered states of consciousness over the course of the combined psychotherapy and internet-based psychoeducational intervention. Overall, results continue to suggest that measures of distress and dissociative experiences can be distinguished by measures of symptom frequency, co-occurrence, and convergence with other measures of distress vs. dissociation albeit that results varied across the four phenomenological dimensions that were surveyed.