Visual phenomenology in schizophrenia and post-traumatic stress disorder: an exploratory study

Abstract

Background Visual experiences such as hallucinations are commonly reported by people with psychosis, psychological trauma and dissociative states, although questions remain about their similarities and differences. For diagnostic and therapeutic purposes, clinical research must better delineate and compare the characteristics of these experiences in post-traumatic stress disorder (PTSD) and in schizophrenia. Aims To compare visual phenomena and dissociation in participants with a primary psychotic illness and those with a trauma diagnosis. Method A quantitative group design study comparing visual phenomena in three participant groups who also have a history of hearing voices: schizophrenia and no trauma history (n = 19), PTSD with dissociation (n = 17) and comorbid schizophrenia and PTSD (n = 20). Validated clinical measures included the North-East Visual Hallucination Interview, PTSD Symptoms Scale Interview, Clinician Administered Dissociative States Scale, Psychotic Symptoms Rating Scales and Positive and Negative Syndrome Scale. Results There was a remarkable similarity in visual experiences, including rates of complex visual hallucinations, between the three diagnostic groups. There were no significant differences in the severity or components of distress surrounding the visual experiences. Dissociation predicted visual hallucination severity for the comorbid schizophrenia and PTSD group, but not for PTSD or schizophrenia alone. Conclusions Visual experiences in PTSD can include visual hallucinations that are indistinguishable from those experienced in schizophrenia. Multimodal hallucinations are frequently observed in both schizophrenia and PTSD. A model for visual hallucinations in PTSD is suggested, following two separate neurobiological pathways based on distinct responses to trauma.

Dissociation, trauma and the experience of visual hallucinations in post-traumatic stress disorder and schizophrenia

“…The study by Wearne and colleagues 15 is an important first step towards the definition of different visual experiences reported by trauma-exposed individuals with PTSD and/or schizophrenia. Different neurobiological systems may further characterise these types of visual experience, in the context of the severity of dissociation reported: flashbacks may be experienced when lower levels of peri-traumatic dissociation are reported, activating the sympathetic nervous system (‘fight or flight’), whereas hallucinations (multimodal, predominantly auditory plus visual) involving the parasympathetic nervous system (‘flag and faint’) are likely to form when more severe and chronic dissociative behaviours are reported.…”

“…This was explored by Wearne and colleagues 15 in the pages of BJPsych Open . The authors compared the phenomenology of visual hallucinations among three groups of individuals, all experiencing auditory hallucinations: a group with a diagnosis of schizophrenia, a group with a diagnosis of PTSD who all experienced dissociation and a group with diagnoses of both schizophrenia and PTSD (schizophrenia + PTSD).…”

Spurious Autobiographical Memory of Psychosis: A Mechanistic Hypothesis for the Resolution, Persistence, and Recurrence of Positive Symptoms in Psychotic Disorders

“…Experiences with PTSD may have some overlap with psychosis. A recent study has found that experiences of visual phenomena in PTSD (flashbacks) and psychosis (visual hallucinations) are similar in terms of their degree of severity and components of distress [131]. Secondary psychotic symptoms have been reported in PTSD [132,133], while several studies have also suggested the experience of psychosis as a trigger for PTSD [134].…”