The Experience and Role of Dissociation in Subclinical Psychosis Following Developmental Trauma: A Mixed-Methods Study

Developmental trauma (DT), in the form of abuse and neglect in childhood and adolescence, induces vulnerability to psychosis in adulthood. Past clinical and general population studies have suggested that dissociation acts as a mediator in the relationship between DT and psychosis. However, there is a lack of research on the experience of dissociation and its mediating role in individuals with subclinical psychosis and DT. In study 1, 1,2450 individuals who reported not receiving psychiatric medication participated in an online survey. In study 2, 64 individuals participated in an experiment using the Mirror Gazing Task (MGT), with measures of pre- and post- depersonalisation. In study 1, we found higher levels of dissociation, absorption, dissociative amnesia and depersonalisation/derealisation among individuals with subclinical psychosis based on the CAPE-15, and among individuals with DT compared to no DT in both the subclinical psychosis and control groups. We identified a mediating role of dissociation and absorption in the relationship between DT and 1)frequency of positive psychotic symptoms as measured by the CAPE-15 and 2) paranoia. We also explored whether the mediating role of dissociation in the relationship between DT and positive psychotic symptoms as measured by the CAPE-15 is moderated by a diagnosis of post-traumatic stress disorder (PTSD) or complex PTSD, and found that dissociation acts as a mediator regardless of the presence of PTSD. Finally, we identified higher change in depersonalisation among participants with DT compared to no DT. Trait and state dissociation appear to be common among individuals with DT, and among individuals with subclinical psychosis, who present with high rates of DT. It is thus important to screen for dissociation among these groups. Future research is needed to understand the phenomenology and mechanisms underlying the relationship between dissociation and psychosis, and if dissociation is associated with worse prognosis and treatment response in individuals with subclinical psychosis and DT.