Open AccessNeurobiological indicators of disinhibition in posttraumatic stress disorder
Author(s) -
Sadeh Naomi,
Spielberg Jeffrey M.,
Miller Mark W.,
Milberg William P.,
Salat David H.,
Amick Melissa M.,
Fortier Catherine B.,
McGlinchey Regina E.
Publication year - 2015
Publication title -
human brain mapping
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.005
H-Index - 191
eISSN - 1097-0193
pISSN - 1065-9471
DOI - 10.1002/hbm.22829
Subject(s) - disinhibition , psychology , middle frontal gyrus , frontal lobe , superior frontal gyrus , neuroscience , functional magnetic resonance imaging , audiology , inferior frontal gyrus , anterior cingulate cortex , psychiatry , medicine , cognition
Deficits in impulse control are increasingly recognized in association with posttraumatic stress disorder (PTSD). To our further understanding of the neurobiology of PTSD‐related disinhibition, we examined alterations in brain morphology and network connectivity associated with response inhibition failures and PTSD severity. The sample consisted of 189 trauma‐exposed Operation Enduring Freedom/Operation Iraqi Freedom veterans (89% male, ages 19–62) presenting with a range of current PTSD severity. Disinhibition was measured using commission errors on a Go/No‐Go (GNG) task with emotional stimuli, and PTSD was assessed using a measure of current symptom severity. Whole‐brain vertex‐wise analyses of cortical thickness revealed two clusters associated with PTSD‐related disinhibition (Monte Carlo cluster corrected P < 0.05). The first cluster included portions of right inferior and middle frontal gyri and frontal pole. The second cluster spanned portions of left medial orbital frontal, rostral anterior cingulate, and superior frontal gyrus. In both clusters, commission errors were associated with reduced cortical thickness at higher (but not lower) levels of PTSD symptoms. Resting‐state functional magnetic resonance imaging analyses revealed alterations in the functional connectivity of the right frontal cluster. Together, study findings suggest that reductions in cortical thickness in regions involved in flexible decision‐making, emotion regulation, and response inhibition contribute to impulse control deficits in PTSD. Furthermore, aberrant coupling between frontal regions and networks involved in selective attention, memory/learning, and response preparation suggest disruptions in functional connectivity may also play a role. Hum Brain Mapp 36:3076–3086, 2015 . © 2015 Wiley Periodicals, Inc.