🚧 Website Maintenance in Progress: Thank you for visiting! We are currently in the process of enhancing our website to serve you better. Please check back soon for our new and improved website.

Individuals vary a great deal in how they respond to a traumatic event:  many people have notable symptoms of posttraumatic stress disorder (PTSD) following trauma exposure that decrease over time, while others suffer with symptoms that persist for years (Bonanno, Westphal, & Mancini, 2011; King, King, Salgado, & Shalev, 2003; Koss & Figueredo, 2004). A sizeable proportion of combat veterans from the Vietnam War continue to suffer severe symptoms 4 to 5 decades after their warzone experiences (Marmar et al., 2015). In order to investigate potential dynamic mechanisms that maintain longstanding symptoms, a newly published study assessed PTSD symptoms every 2 weeks over a 2-year period in 34 male Vietnam combat veterans (Doron-LaMarca, Niles, King, King, Pless Kaiser, & Lyons, In Press). 

Previous research on traumatized individuals has pointed to the hyperarousal symptoms of PTSD (sleep disturbance, irritability and anger, difficulty concentrating, hypervigilance, and exaggerated startle response) as most important in the development and maintenance of PTSD. In this new publication, cross-lagged autoregressive analyses were used to examine four clusters of PTSD symptoms to determine how they influence each other over time: reexperiencing, avoidance, emotional numbing, and hyperarousal. Three important findings emerged from this study. First, hyperarousal was found to be the only PTSD symptom cluster to predict subsequent fluctuations in all three other clusters across 2-week intervals. These findings, together with those from studies of other populations of individuals with PTSD (Marshall et al., 2006; Schell et al., 2004; Solomon et al., 2009), provide strong evidence for the preeminence of hyperarousal as a factor that maintains symptoms of PTSD and reinforce the notion that hyperarousal is the “engine” of PTSD and drives other symptoms (Solomon et al., 2009, p 842).

Second, a cyclical relationship was observed between hyperarousal and reexperiencing in this study. This cycle may be a critical mechanism that maintains PTSD over time: hyperarousal influences reexperiencing, and reexperiencing, in turn, influences hyperarousal. Previous research has identified a strong association between hyperarousal and reexperiencing among Vietnam veterans, and this combination of symptoms may be a “hallmark” of combat-related chronic PTSD (King et al., 1998, p. 94). Third, hyperarousal was found to influence later emotional numbing, which went on to influence later reexperiencing, suggesting a possible chaining of symptoms (hyperarousal à emotional numbing à reexperiencing à hyperarousal) that may amplify the simpler cycle (hyperarousal à reexperiencing à hyperarousal).

Findings from this study suggest that treatments directly targeting the hyperarousal symptoms of PTSD may break the chain of symptom maintenance and may be powerful in the treatment of chronic PTSD. In fact, recent studies have shown that interventions for PTSD that address hyperarousal are successful in reducing symptoms. Treatments aimed at improving sleep (e.g. Margolies, Rybarczyk, Vrana, Leszczyszyn, & Lynch, 2013; Raskind et al., 2013), for example, can reduce PTSD symptoms. Mindfulness meditation has shown promise in ameliorating PTSD symptoms for veterans with PTSD (Bormann, Thorp, Wetherell, Golshan, & Lang, 2013; Niles et al., 2012; Polousny et al., 2015). Relaxation, used as a placebo control in a recent randomized trial of individuals with PTSD (Markowitz et al., 2015), showed surprising efficacy. Yoga for PTSD has been shown to impact hyperarousal symptoms in particular (Staples, Hamilton, & Uddo, 2014) and has been efficacious in reducing overall symptoms (van der Kolk et al., 2014). Exposure treatments that indirectly target hyperarousal through habituation and extinction of fear responses have well-documented efficacy in the treatment of PTSD (e.g. Cahill, Rothbaum, Resick, & Follette, 2009).

Reducing emotional numbing symptoms may also disrupt the chain of PTSD symptom maintenance. This may be why exposure therapies (e.g. Foa et al., 2005; Schnurr et al., 2007) and trauma processing treatments (e.g. Chard, Schuster, & Resick, 2012; Monson et al., 2006) that activate and encourage expression of emotion have been successful in alleviating PTSD symptoms.

The data from this study constitute a rare and valuable view of longstanding PTSD in veterans over time. The dynamic influence of hyperarousal on other symptoms, and the chaining of symptom cluster influences, were identified as possible mechanisms by which symptoms are maintained over time. These findings also suggest targets for successful treatments. Future longitudinal investigations of PTSD symptoms may elucidate the role of other important symptoms, such as guilt and shame, in chronic PTSD. The current study indicates that hyperarousal symptoms continue to stand out in directing the course of PTSD over time.

Author Biographies 

Barbara L. Niles, Ph.D., is a clinical research psychologist in the Behavioral Science Division of the National Center for PTSD at VA Boston Healthcare System and an Assistant Professor of Psychiatry at Boston University School of Medicine. Her research focuses on health and wellness promotion in veterans with PTSD, the longitudinal course of PTSD, and complementary and integrative health interventions.

Anica Pless Kaiser, Ph.D. is a clinical research psychologist in the Behavioral Science Division of the National Center for PTSD at VA Boston Healthcare System and a Research Assistant Professor of Psychiatry at Boston University School of Medicine. Her research interests include understanding the effects of stress and trauma over the lifespan, PTSD symptom course over time, assessment of PTSD and related disorders, development of interventions for older Veterans, and the relationship between PTSD and aging.

Reference Article

Doron-LaMarca, S., Niles, B. L., King, D. W., King, L. A., Pless Kaiser, A., & Lyons, M. J. (2015). Temporal Associations Among Chronic PTSD Symptoms in U.S. Combat Veterans. Journal of Traumatic Stress, 28(5), 410-417. doi: 10.1002/jts.22039



Bonanno, G. A., Westphal, M., & Mancini, A. D. (2011). Resilience to loss and potential trauma. Annual Review of Clinical Psychology7, 511-535. DOI: 10.1146/annurev-clinpsy-032210-104526.

Bormann, J. E., Thorp, S. R., Wetherell, J. L., Golshan, S., & Lang, A. J. (2013). Meditation-based mantram intervention for veterans with posttraumatic stress disorder: A randomized trial. Psychological Trauma: Theory, Research, Practice, and Policy5, 259-267. DOI: 10.1037/a0027522.

Cahill, S. P., Rothbaum, B. O., Resick, P. A., & Follette, V. M. (2009). Cognitive-behavioral therapy for adults. In E.B. Foa, T.M. Keane, M.J. Friedman, & J.A. Cohen (Eds.). Effective treatments for PTSD, 2nd edition (pp. 139-222). New York, NY: Guilford Press.

Chard, K. M., Schuster, J. L., & Resick, P. A. (2012). Empirically Supported Psychological Treatments: Cognitive Processing. The Oxford handbook of traumatic stress disorders, 439-448.

Doron-LaMarca, S., Niles, B. L., King, D. W., King, L. A., Pless Kaiser, A., & Lyons, M. J. (In Press).Temporal associations among chronic PTSD symptoms in combat veterans. Journal of Traumatic Stress.

Foa, E. B., Hembree, E. A., Cahill, S. P., Rauch, S. A., Riggs, D. S., Feeny, N. C., & Yadin, E. (2005). Randomized trial of prolonged exposure for posttraumatic stress disorder with and without cognitive restructuring: outcome at academic and community clinics. Journal of Consulting and Clinical Psychology73, 953-964. DOI: 10.1037/0022-006X.73.5.953.

King, D. W., Leskin, G. A., King, L. A., & Weathers, F. W. (1998). Confirmatory factor analysis of the Clinician-Administered PTSD Scale: Evidence for the dimensionality of posttraumatic stress disorder. Psychological Assessment, 10, 90-96. DOI: 10.1037/1040-3590.10.2.90.

King, L. A., King, D. W., Salgado, D. M., & Shalev, A. Y. (2003). Contemporary longitudinal methods for the study of trauma and stress. CNS Spectrums, 8, 686-692. DOI: 10.1017/S1092852900008877.

Koss, M. P., & Figueredo, A. J. (2004). Change in cognitive mediators of rape's impact on psychosocial health across 2 years of recovery. Journal of Consulting and Clinical Psychology72, 1063-1072. DOI: 10.1037/0022-006X.72.6.1063.

Margolies, S. O., Rybarczyk, B., Vrana, S. R., Leszczyszyn, D. J., & Lynch, J. (2013). Efficacy of a cognitive‐behavioral treatment for insomnia and nightmares in Afghanistan and Iraq veterans with PTSD. Journal of Clinical Psychology69, 1026-1042. DOI: 10.1002/jclp.21970.

Markowitz, J. C., Petkova, E., Neria, Y., Van Meter, P. E., Zhao, Y., Hembree, E., ... & Marshall, R. D. (2015). Is exposure necessary? A randomized clinical trial of interpersonal psychotherapy for PTSD. American Journal of Psychiatry, 172, 430-440.  DOI: 10.1176/appi.ajp.2014.14070908.

Marmar, C. R., Schlenger, W., Henn-Haase, C., Qian, M., Purchia, E., Li, M., ... & Kulka, R. A. (2015). Course of posttraumatic stress disorder 40 years after the Vietnam War: findings from the National Vietnam Veterans Longitudinal Study. JAMA Psychiatry. Retrieved from http://archpsyc.jamanetwork.com. DOI: 10.1001/jamapsychiatry.2015.0803.  

Marshall, G. N., Schell, T. L., Glynn, S. M., & Shetty, V. (2006). The role of hyperarousal in the manifestation of posttraumatic psychological distress following injury. Journal of Abnormal Psychology, 115, 624-628. DOI: 10.1037/0021-843X.115.3.624.

Monson, C. M., Schnurr, P. P., Resick, P. A., Friedman, M. J., Young-Xu, Y., & Stevens, S. P. (2006). Cognitive processing therapy for veterans with military-related posttraumatic stress disorder. Journal of Consulting and Clinical Psychology, 74, 898-907.  DOI: 10.1037/0022-006X.74.5.898.

Niles, B. L., Klunk-Gillis, J., Ryngala, D. J., Silberbogen, A. K., Paysnick, A., & Wolf, E. J. (2012). Comparing mindfulness and psychoeducation treatments for combat-related PTSD using a telehealth approach. Psychological Trauma: Theory, Research, Practice, and Policy, 4, 538-547. DOI: 10.1037/a0026161.

Polusny, M.A., Erbes, C.R., Thuras, P., Moran, A., Lamberty, G.J., Collins, R.C. … & Lim, K.O. (2015). Mindfulness-based stress reduction for posttraumatic stress disorder among veterans: A randomized clinical trial. JAMA, 314, 456-465. DOI: 10.1001/jama.2015.8361.

Raskind, M. A., Peterson, K., Williams, T., Hoff, D. J., Hart, K., Holmes, H., ... & Peskind, E. R. (2013). A trial of prazosin for combat trauma PTSD with nightmares in active-duty soldiers returned from Iraq and Afghanistan. American Journal of Psychiatry170, 1003-1010. DOI: 10.1176/appi.ajp.2013.12081133.

Schell, T. L, Marshall, G. N., & Jaycox, L. H. (2004). All symptoms are not created equal: The prominent role of hyperarousal in the natural course of posttraumatic psychological distress. Journal of Abnormal Psychology, 113, 189-197. DOI: 10.1037/0021-843X.113.2.189.

Schnurr, P. P., Friedman, M. J., Engel, C. C., Foa, E. B., Shea, M. T., Chow, B. K., ... & Bernardy, N. (2007). Cognitive behavioral therapy for posttraumatic stress disorder in women: a randomized controlled trial. Journal of the American Medical Association297, 820-830. DOI: 10.1001/jama.297.8.820.

Solomon, Z., Horesh, D., & Ein-Dor, T. (2009). The longitudinal course of posttraumatic stress disorder symptom clusters among war veterans. Journal of Clinical Psychiatry, 70, 837-843. DOI: 10.4088/JCP.08m04347

Staples, J. K., Hamilton, M. F., & Uddo, M. (2014). A Yoga Program for the Symptoms of Post-Traumatic Stress Disorder in veterans. Military Medicine, 178, 854-860. DOI: 10.7205/MILMED-D-12-00536.

van der Kolk, B., Stone, L., West, J., Rhodes, A., Emerson, D., Suvak, M., & Spinazzola, J. (2014). Yoga as an adjunctive treatment for posttraumatic stress disorder: A randomized controlled trial. Journal of Clinical Psychiatry, 75, 559-565. DOI: 10.4088/JCP.13m08561.