Intrusions in trauma and psychosis: information processing and phenomenology

Intrusions are common symptoms of both post-traumatic stress disorder (PTSD) and schizophrenia. It has been suggested that an information processing style characterized by weak trait contextual integration renders psychotic individuals vulnerable to intrusive experiences. This 'contextual integration hypothesis' was tested in individuals reporting anomalous experiences in the absence of a need for care.

Twenty-six low schizotypes and 23 individuals reporting anomalous experiences were shown a traumatic film with and without a concurrent visuospatial task (VST). Participants rated post-traumatic intrusions for frequency and form, and completed self-report measures of information processing style. It was predicted that, because of their weaker trait contextual integration, the anomalous experiences (AE) group would (1) exhibit more intrusions following exposure to the trauma film, (2) display intrusions characterized by more PTSD qualities and (3) show a greater reduction of intrusions with the concurrent VST.

As predicted, the AE group reported a lower level of trait contextual integration and more intrusions than the low schizotypes, both immediately after watching the film and during the following 7 days. Their post-traumatic intrusive memories were more PTSD-like (more intrusive, vivid and associated with emotion). The VST had no effect on the number of intrusions in either group.

These findings provide some support for the proposal that weak trait contextual integration underlies the development of intrusions within both PTSD and psychosis.