McLean Hospital/Harvard Medical School Belmont, MA, United States
Abstract
Voice-hearing (VH) is the experience of hearing voices in the absence of corresponding external stimuli. The experience is most often associated with schizophrenia and other psychotic disorders, but VH can also present in other psychiatric conditions including trauma-related disorders such as posttraumatic stress disorder (PTSD) and dissociative identity disorder (DID). VH is particularly common among individuals with trauma-related disorders marked by high levels of dissociation (i.e., DID or the dissociative subtype of PTSD). In a sample of patients with severe histories of childhood trauma, PTSD, and some with co-occurring DID, we found that 46% met threshold for VH using the psychosis module of a structured clinical diagnostic interview, while an even higher percentage (91%) endorsed VH when queried with a measure that assesses pathological dissociation.
Voices in trauma-related disorders are often symbolically or thematically related to experienced trauma yet distinct from representations in memory of experienced events such as flashbacks. Critically, VH can be highly distressing and increase suicide risk. However, VH in trauma-related disorders is often underrecognized or dismissed as “pseudo.” Alternatively, at the other end of the spectrum, VH in an individual with a trauma-related disorder can lead to that person being misdiagnosed with schizophrenia. Notably, treatment approaches for schizophrenia are vastly different from treatments that are effective for trauma-related disorders. Thus, misdiagnosis can not only hinder individuals’ ability to access appropriate treatment, resulting in delayed relief from distressing VH, it can also expose individuals to greater risk of harm from the side effects of less appropriate treatments such as antipsychotic medications.
Brain-based measures of VH in trauma-related disorders can provide scientific validity of these experiences and support clinicians to improve diagnostic accuracy and selection of the most appropriate treatments. Recently, we used functional connectivity magnetic resonance imaging (fcMRI) in combination with advanced computational approaches (machine learning) to investigate brain networks associated with VH in 65 women with trauma-related disorders stemming from childhood abuse. We found that VH severity positively correlated with functional connectivity between regions of the auditory cortex and the frontoparietal network, while it negatively correlated with functional connectivity between regions of the auditory cortex and both cerebral and cerebellar representations of the default mode network. These findings point to altered interactions between auditory perceptual processing and higher-level processes related to self-reference and executive functioning. This is the first study to show alterations in auditory cortical connectivity in trauma-related VH. Intriguingly, we found that VH in trauma-related disorders showed a functional connectivity pattern opposite that expected in schizophrenia VH.
It is imperative that clinicians and researchers: (1) become more aware of and recognize VH in trauma-related disorders and (2) learn to distinguish between VH in schizophrenia and trauma-related disorders to avoid misdiagnosis. Our study not only shows that VH in trauma-related disorders is measurable in the brain, it also demonstrates the promise of fcMRI to identify neuroimaging biomarkers that may be able to differentiate VH in trauma-related disorders and schizophrenia.
