Journal of Traumatic Stress June 2015, 28, 183–190 Types and Number of Traumas Associated With Suicidal Ideation and Suicide Attempts in PTSD: Findings From a U.S. Nationally Representative Sample Daniel M. LeBouthillier, Katherine A. McMillan, Michel A. Thibodeau, and Gordon J. G. Asmundson Department of Psychology, University of Regina, Regina, Saskatchewan, Canada Posttraumatic stress disorder (PTSD) is associated with suicidal ideation and suicide attempt; however, research has largely focused on specific samples and a limited range of traumas. We examined suicidal ideation and suicide attempt relating to 27 traumas within a nationally representative U.S. sample of individuals with PTSD. Data were from the National Epidemiologic Survey of Alcohol and Related Conditions (N = 34,653). Participants were assessed for lifetime PTSD and trauma history, suicidal ideation, and suicide attempt. We calculated the proportion of individuals reporting suicidal ideation or suicide attempt for each trauma and for the number of unique traumas experienced. Most traumas were associated with greater suicidal ideation and suicide attempt in individuals with PTSD compared to individuals with no lifetime trauma or with lifetime trauma but no PTSD. Childhood maltreatment, assaultive violence, and peacekeeping traumas had the highest rates of suicidal ideation (49.1% to 51.9%) and suicide attempt (22.8% to 36.9%). There was substantial variation in rates of suicidal ideation and suicide attempt for war and terrorism-related traumas. Multiple traumas increased suicidality, such that each additional trauma was associated with an increase of 20.1% in rate of suicidal ideation and 38.9% in rate of suicide attempts. Rates of suicidal ideation and suicide attempts varied markedly by trauma type and number of traumas, and these factors may be important in assessing and managing suicidality in individuals with PTSD. Suicide and posttraumatic stress disorder (PTSD) affect hun- dreds of thousands of individuals worldwide, causing signif- icant burden on the world’s population. Globally, suicide ac- counts for as much as 1.4% of yearly deaths whereas PTSD ranks among the leading causes of disability (Baxter, Vos, Scott, Ferrari, & Whiteford, 2014; World Health Organization, 2012). In the United States, PTSD is one of the most frequently diag- nosed mental disorders, with a 12-month prevalence of 3.7% and a lifetime prevalence of 8.0 % (Kessler, Petukhova, Samp- son, Zaslavsky, & Wittchen, 2012; Kessler & Ruscio, 2010). Research indicates that individuals with PTSD are more likely to consider or attempt suicide compared to individuals without PTSD (Bernal et al., 2007; Krysinska & Lester, 2010; Sareen et al., 2007; Sareen, Cox, Clara, & Asmundson, 2005; Tarrier & Gregg, 2004). Given that uncompleted suicide attempts are the strongest known predictor of subsequent completed suicide Gordon J. G. Asmundson was supported by a CIHR Operating Grant (FRN: 86658) and Katherine A. McMillan was supported by CIHR Canada Graduate Scholarship Doctoral Research Awards (FRN: 110589). Correspondence regarding this article should be addressed to Daniel M. LeBouthillier, Department of Psychology, University of Regina, 3737 Wascana Parkway, Regina, SK S4S 0A2. E-mail: lebouthd@uregina.ca Copyright C  2015 Wiley Periodicals, Inc., A Wiley Company. View this article online at wileyonlinelibrary.com DOI: 10.1002/jts.22010 (Harris & Barraclough, 1997), delineating the factors that may contribute to suicide attempts within this population is critical. PTSD appears to independently contribute to suicidality be- yond the impact of trauma alone. Indeed, individuals with PTSD are approximately 2–5 times more likely to attempt suicide compared to individuals who experienced a trauma, but do not have PTSD (Pietrzak, Goldstein, Southwick, & Grant, 2011). Moreover, when comparing individuals who are similar in age, sex, ethnicity, education, marital status, and diagnosis of other psychiatric disorder, those with PTSD are more than twice as likely to report suicidal ideation and 2–4 times as likely to en- dorse a suicide attempt than those without PTSD (Thibodeau, Welch, Sareen, & Asmundson, 2013). Previous research has highlighted that the nature of a trau- matic experience is closely associated with subsequent devel- opment of PTSD. For example, traumas of an interpersonal nature (e.g., being raped, being held/captured/kidnapped, be- ing badly beaten) are more likely to lead to the develop- ment of PTSD compared to noninterpersonal traumatic events (e.g., natural disasters, serious car accidents; Breslau, Peter- son, Poisson, Schultz, & Lucia, 2004; Howgego et al., 2005). Whether an individual experienced a trauma directly (e.g., by experiencing the trauma itself) or indirectly (e.g., by learning of a trauma that occurred to someone close) is thought to be another important contributor in the development of the dis- order. Directly experienced traumas are linked with a higher 183