Dissociation—feeling detached from one's body, environment, or self—often accompanies posttraumatic stress disorder (PTSD), but its neural basis is poorly understood. Using network control theory on resting-state functional MRI data, researchers examined brain dynamics during dissociative states in healthy volunteers given ketamine (n=30) and in PTSD patients (n=78) before and after treatment. Ketamine induced brain dynamics similar to those in untreated PTSD patients: increased dominance of the default mode network (DMN) meta-state and decreased dominance of the somatomotor network (SOM) meta-state. After treatment, reduced DMN meta-state dominance correlated with fewer dissociative symptoms. Treated patients also showed more organized, less entropic brain states, though ketamine did not significantly alter entropy indices. Dissociative states, whether drug-induced or clinical, involve increased DMN and reduced SOM dominance.
Dissociation—feeling detached from one's body, surroundings, or self—is common in PTSD but its neural basis is poorly understood. Using network control theory, researchers examined brain dynamics during dissociative states in two contexts: ketamine-induced dissociation in 30 healthy volunteers and therapeutic interventions in 78 PTSD patients. Ketamine produced brain dynamics similar to those seen in PTSD patients before treatment, with increased dominance of a default mode network meta-state and decreased dominance of a somatomotor meta-state. Ketamine did not significantly alter the brain's energetic landscape, but transition energies increased after PTSD treatment, suggesting more organized, less entropic brain dynamics.