Disentangling dissociation

Dissociative experiences, such as feeling detached from yourself or from the world, are common. They play a role in several mental health conditions, including posttraumatic symptoms and psychosis. This dissertation addressed two main questions. First, how are dissociative experiences related to psychotic symptoms in people with schizophrenia spectrum disorders? Second, does the idea that dissociation acts as a protective response help explain memory problems, especially in negative emotional situations?

To address the first question, I examined symptoms as a network. In people with psychosis, dissociative experiences largely formed their own group, rather than simply being a byproduct of psychotic symptoms. The main connection to psychotic symptoms ran through emotional distress. This highlights the importance of feelings such as anxiety and low mood as a bridge between trauma, dissociation, and psychosis. At the same time, my findings show that patterns like these do not allow straightforward conclusions about cause and effect.

For the second question, I critically evaluated brain imaging studies on dissociative identity disorder. The conclusion is that current studies have too many limitations to support strong claims about memory barriers between separate identities. I then conducted two memory studies. In a student sample, dissociation was not clearly related to memory errors. In a virtual reality study that included people with psychosis, higher momentary detachment was associated with greater difficulty linking angry facial expressions to the correct person. Together, these studies show that dissociation is not a vague side issue, and that its link to memory impairment is not trivial. This calls for focused attention in research and clinical practice, as well as greater methodological rigor in research on dissociative experiences.