Assessing traumatic experiences in screening for PTSD in substance use disorder patients: What is the gain in addition to PTSD symptoms? Tim Kok a,b,n , Hein de Haan a,b , Margreet van der Meer c , Lisa Najavits d , Cor de Jong b a Tactus AddictionTreatment, P.O. box 154, 7400 AD Deventer, The Netherlands b Nijmegen Institute for Scientist Practitioners in Addiction, P.O. box 6909, 6503 GK Nijmegen, The Netherlands c Verslavingszorg Noord Nederland, P.O. box 1024, 9701 BA Groningen, The Netherlands d Veterans Affairs Boston Healthcare System and Boston University School of Medicine,150 South Huntington Avenue, Boston, MA 02130, USA article info Article history: Received 15 May 2014 Received in revised form 16 January 2015 Accepted 18 January 2015 Available online 28 January 2015 Key words: Substance use disorder Childhood trauma Child abuse Assessment Posttraumatic stress disorder abstract Traumatic experiences have been linked with substance use disorders (SUD) and may be an important factor in the perpetuation of SUD, even in the absence of posttraumatic stress disorder (PTSD) symptoms. The purpose of the current study was to examine the relationship between childhood trauma and substance use severity in 192 SUD inpatients. Childhood trauma was assessed using the Traumatic Experiences Checklist (TEC). With variables derived from this measure in addition to PTSD symptoms, two regression models were created with alcohol use or drug use severity as dependent variables. Alcohol severity was explained by PTSD symptoms as well as the age of trauma. Drug severity was explained solely by PTSD symptoms. The clinical value of assessing childhood trauma in determining the addiction severity appears to be limited in comparison with PTSD symptoms. & 2015 Elsevier Ireland Ltd. All rights reserved. 1. Introduction Substance use disorders (SUD) are responsible for a large burden on society (Office of National Drug Control Policy, 2004). This burden is often expressed in financial costs, such as those related to hospitalizations, law enforcement, and criminal activ- ities, but SUD can also lead to a large psychological burden on substance users and their environment (Gossop et al., 1998). Effective treatments for SUD are therefore important. The presence of posttraumatic stress disorder (PTSD) is a complicating factor in the treatment of SUD, and high rates of comorbidity of the two disorders are well-documented (Ouimette and Read, 2013). In SUD inpatients, the current prevalence of PTSD ranges from 25% to 51% (Ouimette et al., 2005; Reynolds et al., 2005; Kimerling et al., 2006; Driessen et al., 2008; Kok et al., 2012). In outpatient SUD settings, prevalence rates of current PTSD between 8% and 27% have been found (Graybill et al., 1985; Clark et al., 2001; De Bellis, 2002; Mills et al., 2006; Najavits et al., 2007; Schneider et al., 2007; Driessen et al., 2008). In comparison, epidemiological studies in the general population found a lifetime prevalence of PTSD ranging from 1.3% to 12.3% (Davidson et al., 1991; Resnick et al., 1993; Perkonigg et al., 2000; Kessler et al., 2005). A large proportion of SUD patients experience trauma, but do not develop PTSD. It has been estimated that approximately 90% of SUD patients experienced at least one lifetime trauma (Triffleman et al., 1995; Najavits et al., 1997; Farley et al., 2004). A descriptive study compared alcohol dependent patients with non-SUD patients and found that trauma was much more prevalent in the alcohol dependent patients (Mirsal et al., 2004). Moreover, SUD patients experience more severe trauma and are traumatized more often than people in the general population (Khoury et al., 2010). The impact of trauma on SUD, in the absence of PTSD, is incon- sistent. Some studies show that exposure to trauma increases the risk of SUD (Kilpatrick et al., 2003; Sartor et al., 2007). Also, SUD patients with more severe histories of trauma seem more prone to substance use relapse (Westermeyer et al., 2001; Hyman et al., 2008) and show worse treatment outcomes compared to patients with less severe trauma (Brown and Wolfe, 1994; Hien et al., 2000). However, a longitudinal study by Chilcoat and Breslau (1998) showed that exposure to trauma in the absence of PTSD did not increase the risk of SUD. Given the potential importance of trauma and PTSD on SUD treatment, it is important to have reliable screenings instruments. Integrated treatments, for example, that focus on SUD, trauma- related symptoms and preventing re-traumatization have been shown to produce positive outcomes in both PTSD and SUD symptoms (Zlotnick et al., 2003; Hien et al., 2004; Cocozza et al., Contents lists available at ScienceDirect journal homepage: www.elsevier.com/locate/psychres Psychiatry Research http://dx.doi.org/10.1016/j.psychres.2015.01.014 0165-1781/& 2015 Elsevier Ireland Ltd. All rights reserved. n Corresponding author at: Tactus Addiction Treatment, P.O. box 154, 7400 AD Deventer, The Netherlands. Tel.: þ31 570500100; fax: þ31 570500115. E-mail addresses: t.kok@tactus.nl (T. Kok), h.dehaan@tactus.nl (H. de Haan). Psychiatry Research 226 (2015) 328–332