Feelings of Detachment After Trauma May Signal Worse Mental Health Outcomes
• Research Highlight
Many people experience dissociation, or a lack of connection between their thoughts, memory, and sense of identity, during or after a traumatic experience. A specific type of dissociation—persistent derealization—may put individuals exposed to trauma at greater risk for mental illnesses and functional impairment.
Derealization involves feeling detached from people, places, or objects in one’s environment. Although derealization is linked to worse outcomes following trauma, how or why this occurs is unclear. Clarifying dissociation’s role in trauma-related disorders could have clinical benefit by helping patients understand these experiences and allowing health care providers to intervene to treat or prevent mental illness.
Using data from a large prospective study of post-traumatic psychiatric outcomes (the AURORA study) supported in part by the National Institute of Mental Health, a multisite research team sought to identify underlying neural markers of persistent derealization. The researchers, led by Lauren Lebois, Ph.D., and Kerry Ressler, M.D., Ph.D., at McLean Hospital and Harvard Medical School, investigated whether neural and psychological markers of derealization were associated with later outcomes among people exposed to acute trauma.
The study included 1,464 adults (aged 18–75 years) who came to the emergency department within 72 hours after exposure to a trauma (e.g., motor vehicle collision, physical or sexual assault, mass casualty, or other serious injury or violence). Two weeks after the emergency department visit, participants completed a brief survey measuring symptoms of derealization. A subset (n = 145) of these participants also completed a functional MRI scan to measure activity in three brain regions—ventromedial prefrontal cortex (vmPFC), amygdala, and insula—during an emotion reactivity task and while resting. These areas of the brain are involved in emotion regulation, salience detection, and visceral experiences of the body. Three months post-trauma, all participants provided self-reports of post-traumatic stress disorder (PTSD), depression, and anxiety symptom severity; physical pain; and functional impairment.
The researchers found that approximately half of participants reported symptoms of derealization 2 weeks after trauma exposure. Participants who reported derealization symptoms also showed increased activity in the vmPFC during the emotion reactivity task (with no difference in insula or amygdala activation) and decreased connectivity between the vmPFC and the cerebellum and orbitofrontal cortex, even after accounting for childhood maltreatment history and current post-traumatic stress symptoms that are known to influence these brain circuits.
Furthermore, participants who showed increased vmPFC reactivity tended to have greater symptoms of PTSD 3 months after trauma. Self-reported derealization symptoms in the full sample were also associated with greater symptoms of PTSD and depression 3 months post-trauma. These associations were again independent of childhood maltreatment and earlier PTSD symptoms.
Given that the vmPFC plays a key role in emotion regulation, the authors suggest that overactivation of this brain region may disrupt emotion regulation processes and lead to feelings of detachment following trauma. Moreover, decreased connectivity between the vmPFC and the cerebellum and orbitofrontal cortex, which are involved in sensorimotor input and emotional experience, may contribute to the distortions in perception and emotion that often occur with derealization.
This study highlights the importance of screening for dissociation after trauma to identify people at risk for mental illnesses. Although part of a very large study, the sample with imaging data is relatively small with a shorter duration of follow-up. Replicating this study with a larger sample could identify potential behavioral and neural markers that inform clinical interventions for PTSD, depression, and other trauma-related mental disorders.
Lebois, L. A. M., Harnett, N. G., van Rooij, S. J. H., Ely, T. D., Jovanovic, T., Bruce, S. E., House, S. L., Ravichandran, C., Dumornay, N. M., Finegold, K. E., Hill, S. B., Merker, J. B., Phillips, K. A., Beaudoin, F. L., An, X., Neylan, T. C., Clifford, G. D., Linnstaedt, S. D., Germine, L. T., . . . Ressler, K. J. (2022). Persistent dissociation and its neural correlates in predicting outcomes after trauma exposure. The American Journal of Psychiatry. https://doi.org/10.1176/appi.ajp.21090911