Voided REM Sleep (V-REM)

Abstract

Roughly 40% of patients with post-traumatic stress disorder (PTSD) and roughly 31% of patients with major depressive disorder (MDD) fail to respond to first-line treatment, and the two disorders co-occur in approximately half of all cases. No objective, nocturnal biomarker currently distinguishes which patients will fail to recover, or why. This paper proposes that a subgroup of treatment-resistant patients, across both PTSD and MDD, shows rapid eye movement (REM) sleep that is architecturally normal on a standard sleep study (polysomnography) while exhibiting abnormal functional connectivity between the default mode network, particularly its ventromedial prefrontal cortex (vmPFC) node, and the amygdala, the circuit responsible for overnight emotional memory regulation. Standard REM markers (rapid eye movements, muscle atonia, and characteristic brainwave patterns) are generated autonomously by the brainstem and can appear entirely normal even when this regulatory function has failed. Because both disorders converge on the same vmPFC-amygdala circuit through independent lines of evidence, this failure, termed Voided REM Sleep (V-REM), is proposed as a shared, trans-diagnostic biomarker of treatment resistance rather than a disorder-specific one. The hypothesis is falsifiable: if the same connectivity anomaly appeared just as often in trauma-exposed or dysphoric individuals who never developed a treatment-resistant disorder, V-REM would be refuted. An overnight EEG-fMRI protocol is proposed to test it, with vmPFC-amygdala connectivity measured via the BOLD signal during polysomnographically confirmed REM epochs.