Post-traumatic stress symptoms correlate with smaller subgenual cingulate, caudate, and insula volumes in unmedicated combat veterans

• Published in: Psychiatry research. Neuroimaging 2012-08, Vol.203 (2), p.139-145
• Main Authors: Herringa, Ryan, Phillips, Mary, Almeida, Jorge, Insana, Salvatore, Germain, Anne
• Format: Article
• Language: English
• Subjects: Adult; Adult and adolescent clinical studies; Anxiety; Anxiety disorders. Neuroses; Biological and medical sciences; Brain Mapping; Caudate Nucleus - pathology; Cerebral Cortex - pathology; Circuitry; Combat Disorders - diagnosis; Combat Disorders - pathology; Combat Disorders - psychology; Comorbidity; Dominance, Cerebral - physiology; Female; Gyrus Cinguli - pathology; Humans; Hypothalamus - pathology; Image Interpretation, Computer-Assisted; Iraq War, 2003-2011; Life Change Events; Magnetic Resonance Imaging; Male; Medical sciences; Mental Disorders - diagnosis; Mental Disorders - pathology; Mental Disorders - psychology; Neuroimaging; Organ Size - physiology; Post-traumatic stress disorder; Psychiatry; Psychology. Psychoanalysis. Psychiatry; Psychopathology. Psychiatry; PTSD; Radiology; Reference Values; Statistics as Topic; Stress Disorders, Post-Traumatic - diagnosis; Stress Disorders, Post-Traumatic - pathology; Stress Disorders, Post-Traumatic - psychology; Temporal Lobe - pathology; Trauma; Veterans - psychology
• ISSN: 0925-4927; 1872-7506
• DOI: 10.1016/j.pscychresns.2012.02.005

Abstract Prior studies have examined differences in brain volume between patients with post-traumatic stress disorder (PTSD) and control subjects. Convergent findings include smaller hippocampus and medial prefrontal cortex volumes in PTSD. However, post-traumatic stress symptoms (PTSS) exist on a spectrum, and neural changes may occur beyond the diagnostic threshold of PTSD. We examined the relationship between PTSS and gray matter among combat-exposed U.S. military veterans. Structural brain magnetic resonance imaging (MRI) was obtained on 28 combat veterans from Operations Enduring and Iraqi Freedom. PTSS were assessed using the Clinician-Administered PTSD Scale (CAPS). Thirteen subjects met criteria for PTSD. Subjects were unmedicated, and free of major comorbid psychiatric disorders. Images were analyzed using voxel-based morphometry, and regressed against the total CAPS score and trauma load. Images were subsequently analyzed by diagnosis of PTSD vs. non-PTSD. CAPS scores were inversely correlated with volumes of the subgenual cingulate (sgACC), caudate, hypothalamus, insula, and left middle temporal gyrus (MTG). Group contrast revealed smaller sgACC, caudate, hypothalamus, left insula, left MTG, and right MFG in the PTSD group. PTSS are associated with abnormalities in limbic structures that may underlie the pathophysiology of PTSD. These abnormalities exist on a continuum with PTSS, beyond a diagnosis of PTSD.