How many sessions are Enough How many sessions are Enough? Exposure Therapy with OEF/OIF Veterans with Combat-related Posttraumatic Stress Disorder Benson G. Munyan, III, B.S., Sandra M. Neer, Ph.D., Deborah C. Beidel, Ph.D., ABPP, & Michael A. Gramlich, B.A. Introduction PCL-M Total And Cluster Scores By Session Results Since October of 2001, more than 2.5 million service members have deployed to Iraq and/or Afghanistan (OIF/OEF; Department of Veterans Affairs [VA], 2013). Veterans returning from these conflicts are at increased risk for various physical and mental conditions, including posttraumatic stress disorder (PTSD; Hermann et al., 2012; Hoge et al., 2004; Richardson et al., 2010). Exposure therapy (EXP) is an efficacious treatment for PTSD resulting from a wide variety of traumatic events, including combat (Foa et al., 2008). Although a strong evidence base exists, manualized treatments prescribe a specific number of exposure sessions without knowing the optimal number of sessions necessary. In the age of managed care, unneeded sessions are wasteful and burdensome to an overtaxed healthcare system. However, therapists may not be sure when EXP can be safely discontinued. The purpose of this study was to evaluate the number of sessions needed to achieve symptom remission in a 15 session treatment protocol. Regression utilizing elastic net regularization indicated that PTSD symptoms continued to decrease from baseline until session 10 (p = .022), regardless of initial severity. Additionally, symptoms in both the re-experiencing cluster (p = .007) and the hyperarousal cluster (p=.034) declined significantly until session 10; however, symptoms in the avoidance/numbing cluster declined significantly only until session 7 (p = .042). With regard to overall improvement, total PCL-M scores at session 10 showed a mean reduction of 41%, with a reduction in mean scores from 61 to 36. With regard to symptom reduction by cluster, we found improvement of 43%, 44%, and 36% for re-experiencing, avoidance/numbing, and hyperarousal, respectively. The percentage of individuals who still met the commonly used cutoff for PTSD (50) at session 10 was 23%. Discussion Method Regardless of baseline severity of combat-related PTSD, 10 EXP sessions were shown to be adequate for PTSD improvement for 77% of the sample, with no further immediately significant benefit from additional sessions. In addition, this finding held true for symptom clusters suggesting that EXP is effective in reducing symptoms across all 3 clusters (re-experiencing, avoidance and hyperarousal) in 10 sessions. These findings suggest that additional sessions after session ten may be wasteful, as they consume facility resources, therapist time, and patient time, which may result in lost productivity elsewhere. However, while there was not immediate benefit to PCL-M scores after session ten, it is currently unknown what role additional sessions after session ten have on emotional and behavioral functionality long term. Given that research has not empirically examined long term outcome differences stemming from possible differences between those who receive ten or more sessions, future research is warranted. It is possible that additional sessions after symptom improvement slows may facilitate more favorable long term outcomes. Treatment-seeking OIF/OEF military combat personnel were evaluated for a randomized controlled trial of Trauma Management Therapy (Frueh et al., 1996; Turner et al., 2005) for PTSD funded by the Military Operational Medicine Research Program. 48 combat veterans met criteria for PTSD (DSM-IV-TR; American Psychiatric Association, 2000) as assessed by the Clinician Administered PTSD Scale (CAPS; Blake et al., 1995) and were part of a larger DOD-funded study in which EXP was conducted three times per week for five weeks. Symptom improvement was assessed by the Posttraumatic Stress Disorder Checklist, Military Version (PCL-M; Weathers et al., 1994) which was administered every third session (once per week). Table 1. Participant Demographics OIF/OEF Combat Personnel (n = 48) Age M(SD) 36.60 (10.68) n (%) Sex (male) 46 (95.8) Race Caucasian 27 (56.2) African American 3 (6.2) Latino 16 (33.3) Asian American 1 (2.0) Other Marital Status Single Married 23 (47.9) Divorced 4 (8.3) Separated 5 (10.4) Service Status (Active) 11 (22.9) Questions or Comments? Please contact Benson G. Munyan at: benson.munyan@knights.ucf.edu