TY - JOUR
T1 - A Twin Study of Genetic and Environmental Contributions to Liability for Posttraumatic Stress Symptoms
AU - True, William R.
AU - Rice, John
AU - Eisen, Seth A.
AU - Heath, Andrew C.
AU - Goldberg, Jack
AU - Lyons, Michael J.
AU - Nowak, Justina
PY - 1993/4
Y1 - 1993/4
N2 - We studied 4042 Vietnam era veteran monozygotic and dizygotic male twin pairs to determine the effects of heredity, shared environment, and unique environment on the liability for 15 self-reported posttraumatic stress disorder symptoms included in the symptom categories of reexperiencing the trauma, avoidance of stimuli related to the trauma, and increased arousal. Quantitative genetic analysis reveals that inheritance has a substantial influence on liability for all symptoms. Symptoms in the reexperiencing cluster and one symptom in the avoidance and numbing cluster are strongly associated with combat exposure, and monozygotic pairs are more highly concordant for combat exposure than dizygotic pairs. By fitting a bivariate genetic model, we show that there are significant genetic influences on symptom liability, even after adjusting for differences in combat exposure; genetic factors account for 13% to 30% of the variance in liability for symptoms in the reexperiencing cluster, 30% to 34% for symptoms in the avoidance cluster, and 28% to 32% for symptoms in the arousal cluster. There is no evidence that shared environment contributes to the development of posttraumatic stress disorder symptoms.
AB - We studied 4042 Vietnam era veteran monozygotic and dizygotic male twin pairs to determine the effects of heredity, shared environment, and unique environment on the liability for 15 self-reported posttraumatic stress disorder symptoms included in the symptom categories of reexperiencing the trauma, avoidance of stimuli related to the trauma, and increased arousal. Quantitative genetic analysis reveals that inheritance has a substantial influence on liability for all symptoms. Symptoms in the reexperiencing cluster and one symptom in the avoidance and numbing cluster are strongly associated with combat exposure, and monozygotic pairs are more highly concordant for combat exposure than dizygotic pairs. By fitting a bivariate genetic model, we show that there are significant genetic influences on symptom liability, even after adjusting for differences in combat exposure; genetic factors account for 13% to 30% of the variance in liability for symptoms in the reexperiencing cluster, 30% to 34% for symptoms in the avoidance cluster, and 28% to 32% for symptoms in the arousal cluster. There is no evidence that shared environment contributes to the development of posttraumatic stress disorder symptoms.
UR - http://www.scopus.com/inward/record.url?scp=0027410515&partnerID=8YFLogxK
U2 - 10.1001/archpsyc.1993.01820160019002
DO - 10.1001/archpsyc.1993.01820160019002
M3 - Article
C2 - 8466386
AN - SCOPUS:0027410515
SN - 0003-990X
VL - 50
SP - 257
EP - 264
JO - Archives of General Psychiatry
JF - Archives of General Psychiatry
IS - 4
ER -