Hallucinations as sensory-perceptual intrusions from traumatic memory: Empirical investigation of a phenomenologically important subgroup.

Objective: Past research has identified links between experiences of trauma and the content of hallucinations. There has not been an investigation of differences between those with trauma who do and do not have hallucinations with trauma-related content. This study explored the phenomenology and clinical correlates of hallucinations that contain matching sensory-perceptual elements to trauma.

Method: 64 young people engaged with an early psychosis service completed assessments of trauma, psychosis, posttraumatic stress disorder (PTSD), and dissociation. A theoretically informed coding frame was developed to (a) identify matching sensory-perceptual elements in hallucinations, posttraumatic intrusions, and trauma memories and (b) explore the phenomenology of such hallucinations. Differences in the severity of childhood trauma, posttraumatic intrusions, hyperarousal, dissociation, and PTSD diagnoses for those with and without hallucinations containing matching sensory-perceptual elements from trauma were examined.

Results: Twenty percent (n = 12) of those with a history of trauma and hallucinations experienced a hallucination that contained a matching sensory-perceptual element to an experience of trauma or a posttraumatic intrusion. Seventy-one percent of hallucinations with a matching sensory-perceptual element to trauma also contained novel content. The two groups did not differ in the severity of childhood trauma, posttraumatic intrusions, hyperarousal, dissociation, or rates of PTSD diagnoses.

Conclusions: Results are consistent with literature showing that a clinically significant minority of those with trauma and hallucinations experience hallucinations that contain intrusions of traumatic memories. The presence of novel content within these same hallucinations suggests multiple processes may work together to inform the content of one hallucination. (PsycInfo Database Record (c) 2025 APA, all rights reserved).