Differences in posttraumatic stress disorder diagnostic rates and symptom severity between Criterion A1 and non-Criterion A1 stressors Mary E. Long a,1 , Jon D. Elhai a, * , Amy Schweinle b , Matt J. Gray c , Anouk L. Grubaugh d,e , B. Christopher Frueh f,2 a Disaster Mental Health Institute, Department of Psychology, The University of South Dakota, Vermillion, SD, United States b Division of Counseling and Psychology, School of Education, The University of South Dakota, Vermillion, SD, United States c Department of Psychology, University of Wyoming, Laramie, WY, United States d Department of Psychiatry and Behavioral Sciences, Medical University of South Carolina, Charleston, SC, United States e Ralph H. Johnson Veterans Affairs Medical Center, Charleston, SC, United States f Department of Psychology, University of Hawai’i at Hilo, Hilo, HI, United States Received 5 November 2007; received in revised form 5 January 2008; accepted 7 January 2008 Abstract This study addresses the ongoing controversy regarding the definition of DSM-IV posttraumatic stress disorder’s (PTSD) traumatic stressor criterion (A1). A sample of 119 college students completed the PTSD Symptom Scale separately in relation to both Criterion A1 and non-Criterion A1 stressful events, using a mixed between-groups (administration order) and within-subjects (stressor type) design. Contrary to what was expected, analyses revealed that non-Criterion A1 events were associated with greater likelihood of ‘‘probable’’ PTSD diagnoses and a greater PTSD symptom frequency than Criterion A1 events. Symptom frequency relationships, however, were moderated by the order in which the measures were administered. The non-Criterion A1 PTSD scores were only higher when non-Criterion A1 measures were presented first in the administration order. Similar patterns of differences in PTSD scores between stressor types were also found across the three PTSD symptom criteria. Implications are discussed as to the ongoing controversy of the PTSD construct. # 2008 Elsevier Ltd. All rights reserved. Keywords: Posttraumatic stress disorder; Criterion A1; Psychological assessment; Emotional trauma; Diagnosis 1. Introduction There has been controversy as to the definition of posttraumatic stress disorder’s (PTSD) traumatic stressor criterion since PTSD first appeared in the DSM-III. Currently, this criterion (A1, in DSM-IV) represents an attempt to provide an objective definition of the traumatic event that is necessary for the validity of the PTSD diagnosis (American Psychiatric Associa- tion, 2000). Despite the ongoing controversy, there is little empirical research exploring whether events Journal of Anxiety Disorders 22 (2008) 1255–1263 * Corresponding author at: Disaster Mental Health Institute, Depart- ment of Psychology, Vermillion, SD 57069, United States. Tel.: +1 605 624 6575; fax: +1 203 413 6227. E-mail addresses: jon.elhai@usd.edu, jonelhai@fastmail.fm (J.D. Elhai). 1 Currently affiliated with National Crime Victims Research and Treatment Center, MUSC, and Ralph H. Johnson Veterans Affairs Medical Center, Charleston, SC, United States. 2 Currently affiliated with Menninger Department of Psychiatry and Behavioral Sciences, Baylor College of Medicine, Houston, Texas. 0887-6185/$ – see front matter # 2008 Elsevier Ltd. All rights reserved. doi:10.1016/j.janxdis.2008.01.006