  Posttraumatic stress disorder (PTSD) is a chronic and disabling
neuropsychiatric disorder characterized by insufficient top-down modulation of
the amygdala activity by the prefrontal cortex. Real-time fMRI neurofeedback
(rtfMRI-nf) is an emerging method with potential for modifying the
amygdala-prefrontal interactions. We report the first controlled emotion
self-regulation study in veterans with combat-related PTSD utilizing rtfMRI-nf
of the amygdala activity. PTSD patients in the experimental group (EG, n=20)
learned to upregulate BOLD activity of the left amygdala (LA) using rtfMRI-nf
during a happy emotion induction task. PTSD patients in the control group (CG,
n=11) were provided with a sham rtfMRI-nf. The study included three rtfMRI-nf
training sessions, and EEG recordings were performed simultaneously with fMRI.
PTSD severity was assessed using the Clinician-Administered PTSD Scale (CAPS).
The EG participants showed a significant reduction in total CAPS ratings,
including significant reductions in avoidance and hyperarousal symptoms.
Overall, 80% of the EG participants demonstrated clinically meaningful
reductions in CAPS ratings, compared to 38% in the CG. During the first
session, fMRI connectivity of the LA with the orbitofrontal cortex and the
dorsolateral prefrontal cortex (DLPFC) was progressively enhanced, and this
enhancement significantly and positively correlated with initial CAPS ratings.
Left-lateralized enhancement in upper alpha EEG coherence also exhibited a
significant positive correlation with the initial CAPS. Reduction in PTSD
severity between the first and last rtfMRI-nf sessions significantly correlated
with enhancement in functional connectivity between the LA and the left DLPFC.
Our results demonstrate that the rtfMRI-nf of the amygdala activity has the
potential to correct the amygdala-prefrontal functional connectivity
deficiencies specific to PTSD.
