Article |

Genetic and Environmental Influences of Twins in Posttraumatic Stress-Reply

William R. True, PhD, MPH; John Rice, PhD; Andrew C. Heath, DPhil
Arch Gen Psychiatry. 1994;51(10):838-839. doi:10.1001/archpsyc.1994.03950100086009.
Text Size: A A A
Published online

In reply  Lurie and Geyer question our finding that shared environment did not contribute to susceptibility to posttraumatic stress disorder symptoms in our study of 2224 MZ and 1818 DZ male veteran twins. 1 They base their argument on the validity of the equal environments assumption of twin studies, which is that MZ and DZ twins do not differ in exposure to etiologically relevant environmental influences.Although, as stated in the article, we did not have data in our study to test directly this assumption, the issue has received considerable critical attention in the twin literature, most recently in Kendler' s2 comprehensive review of the role of twin studies of psychiatric illness and in a review of genetic approaches to personality by Eaves et al:3 The issue is that if the phenotypic similarity of MZ twins is actually attributed to shared environments that are more uniform, then genetic contributions will


Sign In to Access Full Content

Don't have Access?

Register and get free email Table of Contents alerts, saved searches, PowerPoint downloads, CME quizzes, and more

Subscribe for full-text access to content from 1998 forward and a host of useful features

Activate your current subscription (AMA members and current subscribers)

Purchase Online Access to this article for 24 hours

First Page Preview

View Large
First page PDF preview





Meets CME requirements for:
Browse CME for all U.S. States
Accreditation Information
The American Medical Association is accredited by the Accreditation Council for Continuing Medical Education to provide continuing medical education for physicians. The AMA designates this journal-based CME activity for a maximum of 1 AMA PRA Category 1 CreditTM per course. Physicians should claim only the credit commensurate with the extent of their participation in the activity. Physicians who complete the CME course and score at least 80% correct on the quiz are eligible for AMA PRA Category 1 CreditTM.
Note: You must get at least of the answers correct to pass this quiz.
You have not filled in all the answers to complete this quiz
The following questions were not answered:
Sorry, you have unsuccessfully completed this CME quiz with a score of
The following questions were not answered correctly:
Commitment to Change (optional):
Indicate what change(s) you will implement in your practice, if any, based on this CME course.
Your quiz results:
The filled radio buttons indicate your responses. The preferred responses are highlighted
For CME Course: A Proposed Model for Initial Assessment and Management of Acute Heart Failure Syndromes
Indicate what changes(s) you will implement in your practice, if any, based on this CME course.
Citing articles are presented as examples only. In non-demo SCM6 implementation, integration with CrossRef’s "Cited By" API will populate this tab (http://www.crossref.org/citedby.html).
Submit a Comment


Some tools below are only available to our subscribers or users with an online account.

Sign In to Access Full Content

Related Content

Customize your page view by dragging & repositioning the boxes below.