The results highlight the importance of screening for dissociation in patients who have experienced trauma, study investigator Lauren A.M. Lebois, PhD, director of the dissociative disorders and trauma research program at McLean Hospital in Belmont, Mass., told this news organization.
“Clinicians could identify individuals potentially at risk of a chronic, more severe psychiatric course before these people go down that road, and they have the opportunity to connect folks with a phased trauma treatment approach to speed their recovery,” said Dr. Lebois, who is also an assistant professor of psychiatry at Harvard Medical School, Boston.
The study was published in the American Journal of Psychiatry.
Underdiagnosed
Feelings of detachment or derealization are a type of dissociation. Patients with the syndrome report feeling foggy or as if they are in a dream. Dissociative diagnoses are not rare and, in fact, are more prevalent than schizophrenia.
Research supports a powerful relationship between dissociation and traumatic experiences. However, dissociation is among the most stigmatized of psychiatric conditions. Even among clinicians and researchers, beliefs about dissociation are often not based on the scientific literature, said Dr. Lebois.
“For instance, skepticism, misunderstanding, and lack of professional education about dissociation all contribute to striking rates of underdiagnosis and misdiagnoses,” she said.
Dr. Lebois and colleagues used data from the larger Advancing Understanding of Recovery After Trauma (AURORA) study and included 1,464 adults, mean age 35 years, appearing at 22 U.S. emergency departments. Patients experienced a traumatic event such as a motor vehicle crash or physical or sexual assault.
About 2 weeks after the trauma, participants reported symptoms of derealization as measured by a two-item version of the Brief Dissociative Experiences Scale.
Brain imaging data
A subset of 145 patients underwent functional MRI (fMRI), during which they completed an emotion reactivity task (viewing fearful-looking human faces) and a resting-state scan.
In addition to measuring history of childhood maltreatment, researchers assessed posttraumatic stress symptom severity at 2 weeks and again at 3 months using the posttraumatic stress disorder checklist. Also at 3 months, they measured depression and anxiety symptoms, pain, and functional impairment.
About 55% of self-report participants and 50% of MRI participants endorsed some level of persistent derealization at 2 weeks.
After controlling for potential confounders, including sex, age, childhood maltreatment, and current posttraumatic stress symptoms, researchers found persistent derealization was associated with increased ventromedial prefrontal cortex (vmPFC) activity while viewing fearful faces.
The vmPFC helps to regulate emotional and physical reactions. “This region puts the ‘brakes’ on your emotional and physical reactivity – helping you to calm down” after a threatening or stressful experience has passed, said Dr. Lebois.
Researchers also found an association between higher self-reported derealization and decreased resting-state connectivity between the vmPFC and the orbitofrontal cortex and right lobule VIIIa – a region of the cerebellum involved in sensorimotor function.
“This may contribute to perceptual and affective distortions experienced during derealization – for example, feelings that surroundings are fading away, unreal, or strange,” said Dr. Lebois.