Habenula volume in post-traumatic stress disorder measured with high-resolution MRI

Jonathan B Savitz,Wayne C Drevets,Wendy Bogers,Meena Vythilingam,Omer Bonne,Dennis S Charney,Allison C Nugent

doi:10.1186/2045-5380-1-7

Abstract

BackgroundThe habenula plays an important role in regulating behavioral responses to stress and shows increased cerebral blood flow and decreased gray matter volume in patients with mood disorders. Here, we compare the volume of the habenula in unmedicated patients with post-traumatic stress disorder (PTSD) and healthy controls (HC) using MRI.FindingsHigh-resolution images (resolution of approximately 0.4 mm3) were acquired using a 3T scanner and a pulse sequence optimized for tissue contrast resolution. The habenula was manually segmented by one rater blind to diagnosis. PTSD and HC participants did not differ significantly in absolute or normalized habenula volume. Post hoc analyses controlling for the effects of comorbid major depressive disorder (MDD) and type and age of trauma exposure were not significant. Further, there was no association between PTSD severity and habenula volume.ConclusionsOur data suggest that PTSD is not associated with robust structural changes in the habenula. The modest size of the PTSD sample may have reduced statistical power thereby accounting for the negative results obtained.

Highlights

Post-traumatic stress disorder (PTSD) is associated with an impaired ability to extinguish conditioned fear responses to threatening stimuli
In humans, using arterial spin labeling and an emotional word processing paradigm we have previously shown that remitted major depressive disorder (MDD) patients had greater blood flow to the habenula than healthy controls after acute tryptophan depletion [10]
A recent postmortem study reported a reduction in volume, neuronal numbers and neuronal cell area of the medial habenula in patients with affective illness [11]. Consistent with these data, we recently reported a decrease in the habenula volume of unmedicated patients with bipolar disorder (BD) and female patients with MDD [12]

Summary

Introduction

Post-traumatic stress disorder (PTSD) is associated with an impaired ability to extinguish conditioned fear responses to threatening stimuli. This deficit attributed is hypothesized to reflect deficient inhibition of the amygdala by the ventromedial prefrontal cortex (vmPFC) [1,2,3]. The habenula may a key role in the inhibition of conditioned fear, and by extension, PTSD. The habenula plays an important role in regulating behavioral responses to stress and shows increased cerebral blood flow and decreased gray matter volume in patients with mood disorders. We compare the volume of the habenula in unmedicated patients with post-traumatic stress disorder (PTSD) and healthy controls (HC) using MRI. There was no association between PTSD severity and habenula volume

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Results

Conclusion