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Updated: May 14, 2026
Biomarkers in an Animal Model for Revealing Neural, Hematologic, and Behavioral Correlates of PTSD
Published on: October 10, 2012
Higher in vivo serotonin-1a binding in posttraumatic stress disorder: a PET study with [11C]WAY-100635
Gregory M Sullivan1, R Todd Ogden, Yung-Yu Huang
1Department of Psychiatry, Columbia University College of Physicians & Surgeons, New York, NY, USA.
Background:
Brain serotonin-1A receptors (5-HT1A ) are implicated in anxiety. We compared regional brain 5-HT1A binding in medication-free participants with posttraumatic stress disorder (PTSD) and healthy volunteers using fully quantitative positron emission tomography (PET) methods.
Methods:
Twenty patients with DSM-IV PTSD (13 with comorbid major depressive disorder, [MDD]) and 49 healthy volunteers underwent PET imaging with 5-HT1A antagonist radioligand [C-11]WAY100635. Arterial blood sampling provided a metabolite-corrected input function and the concentration of free ligand in plasma (fP ) for estimation of regional binding potential, BPF ( = Bavailable / KD ). Linear mixed modeling compared BPF between groups across regions of interest (ROIs).
Results:
The PTSD group had higher 5-HT1A BPF across brain ROIs (P = .0006). Post hoc comparisons showed higher 5-HT1A BPF in PTSD in all cortical ROIs (26-33%), amygdala (34%), and brainstem raphe nuclei (43%), but not hippocampus. The subgroup of seven PTSD patients without comorbid MDD had higher 5-HT1A BPF compared with healthy volunteers (P = .03).
Conclusions:
This is the first report of higher brainstem and forebrain 5-HT1A binding in vivo in PTSD. The finding is independent of MDD. PTSD and MDD have in common an upregulation of 5-HT1A binding including midbrain autoreceptors that would favor less firing and serotonin release. This abnormality may represent a common biomarker of these stress-associated brain disorders.
