Since posttraumatic stress disorder
(PTSD) was firstrecognized
as a psychiatric disorder, it has generateda
great deal of scientific interest. Recent studies onthe
neurobiology of PTSD provide evidence that PTSDis
biologically distinct from other types of traumaticand
nontraumatic stress responses. This paper reviewsthree
important directions of
neurobiologicalresearch
in PTSD: noradrenergic axis changes andassociated
alterations in autonomic responsivity, neu-roendocrine
changes involving the hypothalamic-pitu-itary-adrenocortical
(HPA) axis, and neuroanatomicchanges
involving the hippocampus. Each sectionreviews the salient aspects of preclinical
research onthe
biology of stress and their bearing on the under-standing
of PTSD, and summarizes prominent find-ings
from clinical biological studies of PTSD. Tenta-tive
models that integrate current findings from theclinical
study of PTSD are reviewed. To conclude, theimportant
methodological and empirical issues thatneed
to be addressed by future studies are indicated. ince
posttraumatic stress disorder (PTSD)was
first recognized as a psychiatric disorder in theDiagnostic
and Statistical Manual of Mental Disorders,3rd
edition (DSM-III) in 1980,1 it
has generatedtremendous
scientific and public interest. Research onPTSD
has only served to elucidate the great complex-ity
of this disorder. While early theoreticians viewedPTSD
as part of the continuum of normal stressresponses, recent studies indicate
that the biologicalpatterns
seen in PTSD are different from biologicalresponses
to nontraumatic stress.2 Researchers
havemade important
advances in characterizing the neuro-biological
features of PTSD and distinguishing biolog-ical
features associated with PTSD from patterns asso-ciated
with other types of reactions to traumatic andnontraumatic
stressors. This paper reviews three impor-tant
directions of neurobiological research in PTSD:noradrenergic
axis changes and associated alterationsin
autonomic responsivity, neuroendocrine changesinvolving the hypothalamic-pituitary-adrenal
(HPA)axis, and
neuroanatomic changes involving the hip-pocampus.Noradrenergic axis function in PTSDTo react appropriately to danger, both
animals andhumans
must rapidly marshal a complex set of behav-ioral
responses. The locus ceruleus (LC), which
islocated
in the dorsal pons, plays a crucial role in acti-vating
central and peripheral nervous system responsesto
threat. Through its broad connections with corticalstructures, the hippocampus, hypothalamus, amygdala,Neurobiological
findings in
posttraumatic stress disorder: a reviewKumar
Vedantham, MD; Alain Brunet, PhD; Thomas C. Neylan, MD; DanielS. Weiss, PhD; Charles
R. Marmar, MDAuthor
affiliations: Department of Psychiatry, University of California, San Francisco;
and Department of Veterans Affairs, Medical Center, San Fran-cisco, Calif, USA.
Kumar Vedantham acknowledges fellowship support from the Program for Minority
Research Training in Psychiatry (PMRTP), which is funded by the National Institute
of Mental Health and administered by the American Psychiatric Association. Alain
Brunet acknowledges financial support from the Fonds de Recherche en Santé
du Québec.Address
for correspondence: Kumar Vedantham, Department of Psychiatry, University of California,
SFVAMC Psychiatry Service (116P), 4150 Clement Street, San Francisco CA 94121-1545,
USA
(e-mail: kumar@itsa.ucsf.edu) 2 3SB a s i c
r e s e a r c h
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