Original Research

Yoga as an Adjunctive Treatment for Posttraumatic Stress Disorder: A Randomized Controlled Trial Bessel A. van der Kolk, MD; Laura Stone, MA; Jennifer West, PhD; Alison Rhodes, MSW Med; David Emerson, E-RYT; Michael Suvak, PhD; and Joseph Spinazzola, PhD

ABSTRACT Background: More than a third of the approximately 10 million women with histories of interpersonal violence in the United States develop posttraumatic stress disorder (PTSD). Currently available treatments for this population have a high rate of incomplete response, in part because problems in affect and impulse regulation are major obstacles to resolving PTSD. This study explored the efficacy of yoga to increase affect tolerance and to decrease PTSD symptomatology.

Method: Sixty-four women with chronic, treatment-resistant PTSD were randomly assigned to either trauma-informed yoga or supportive women’s health education, each as a weekly 1-hour class for 10 weeks. Assessments were conducted at pretreatment, midtreatment, and posttreatment and included measures of DSM- IV PTSD, affect regulation, and depression. The study ran from 2008 through 2011.

Results: The primary outcome measure was the Clinician- Administered PTSD Scale (CAPS). At the end of the study, 16 of 31 participants (52%) in the yoga group no longer met criteria for PTSD compared to 6 of 29 (21%) in the control group (n = 60, χ21 = 6.17, P = .013). Both groups exhibited significant decreases on the CAPS, with the decrease falling in the large effect size range for the yoga group (d = 1.07) and the medium to large effect size decrease for the control group (d = 0.66). Both the yoga (b = −9.21, t = −2.34, P = .02, d = −0.37) and control (b = −22.12, t = −3.39, P = .001, d = −0.54) groups exhibited significant decreases from pretreatment to the midtreatment assessment. However, a significant group × quadratic trend interaction (d = −0.34) showed that the pattern of change in Davidson Trauma Scale significantly differed across groups. The yoga group exhibited a significant medium effect size linear (d = −0.52) trend. In contrast, the control group exhibited only a significant medium effect size quadratic trend (d = 0.46) but did not exhibit a significant linear trend (d = −0.29). Thus, both groups exhibited significant decreases in PTSD symptoms during the first half of treatment, but these improvements were maintained in the yoga group, while the control group relapsed after its initial improvement.

Discussion: Yoga significantly reduced PTSD symptomatology, with effect sizes comparable to well-researched psychotherapeutic and psychopharmacologic approaches. Yoga may improve the functioning of traumatized individuals by helping them to tolerate physical and sensory experiences associated with fear and helplessness and to increase emotional awareness and affect tolerance.

Trial Registration: ClinicalTrials.gov identifier: NCT00839813

J Clin Psychiatry 2014;75(6):e559–e565 © Copyright 2014 Physicians Postgraduate Press, Inc.

Submitted: May 2, 2013; accepted November 14, 2013 (doi:10.4088/JCP.13m08561). Corresponding author: Bessel A. van der Kolk, MD, Trauma Center at Justice Resource Institute, 1269 Beacon St, Brookline, MA 02446 (bessel1@mac.com).

Approximately 9.8 million adult American women (about 10% of the adult female population) have histories of violent physical assaults, and 12.1 million (12.7%) report having been a victim of completed rapes.1 More than a third of these traumatic experiences result in the development of posttraumatic stress disorder (PTSD) and are also associated with a range of other comorbid disorders, such as anxiety and depression, as well as physical health problems, including obesity, heart disease, and chronic pain syndromes.2–7

Various forms of exposure treatment have been shown to be useful in the treatment of PTSD.8–11 However, they have a high rate of incomplete response. In a recent large clinical trial11 of prolonged exposure, 59% of subjects still had PTSD after 12 weeks of treatment, and 78% remained symptomatic at 6-month follow-up. A meta-analytic review12 of psychosocial treatments for PTSD found that the majority of treatment-seeking populations continue to show substantial residual symptoms and that less than half of patients completing cognitive-behavioral treatment interventions show clinically meaningful improvement. The Institute of Medicine found that the currently available scientific evidence for the treatment for PTSD does not reach the level of certainty that would be desired for such a common and serious condition.13

Chronic trauma exposure is associated with significant problems in affect and impulse regulation.14,15 Becoming flooded or dissociating interferes with the resolution of traumatic memories16–20 and is associated with high dropout rates or symptom worsening.16,18,20 The successful extinction of conditioned fear responses, thought to be critical for the resolution of PTSD, requires being able to manage intense emotions and to keep one’s attention focused on conditioned stimuli, ie, sensory input emanating from the environment or from within the organism.16,17,19,21

Mindfulness meditation, nonjudgmental attention to experiences in the present moment, has been shown to facilitate affect regulation.21–23 However, traumatized individuals tend to have difficulty tolerating unstructured meditation and do much better with an instructor whose guidance helps them maintain their focus on bodily sensations, while modulating arousal with breathing exercises, as is done in a yoga practice.24

It is estimated that yoga is regularly practiced by over 26 million individuals in the United States; it is among the top 10 most widely practiced forms of complementary health care in the United States.25 Yoga is a comprehensive system of practices that incorporates physical postures, breathing

Notice of correction 7/3/2014: Mr David Emerson holds the nonacademic credential “Experienced-Registered Yoga Teacher” (E-RYT) from the Yoga Alliance.

The online version has been corrected to reflect this credential.




J Clin Psychiatry 75:6, June 2014

van der Kolk et al

exercises, and meditation/concentration techniques that have been shown to be associated with changes in autonomic function, muscle strength, blood pressure, heart rate, respiration, plasma cortisol, urinary catecholamines, and improvement in arousal regulation.26–39

Yoga has been studied as an effective adjunctive treatment for a large variety of medical disorders, including asthma, heart disease and hypertension, diabetes, chronic pain, arthritis, and insomnia.27,29,40–45 Other studies also have demonstrated positive effects of yoga on depression and anxiety46–49 and on acute stress reactions.50–52

The physical postures of hatha yoga emphasize flexibility over aerobic fitness. In yoga, the focus of attention is on sensory experiences of breathing and physical sensations. The heightened body awareness fostered by yoga can help to detect physiological aspects of physical sensations (eg, body tension, rapid heartbeat, and short, shallow breath) and provide information about the internal milieu, a prerequisite for accurate identification of the triggered emotional response (ie, fear).16,21,24,53 The mindfulness aspect of yoga is hypothesized to foster emotion regulation by simply noticing the fear, as opposed to engaging in avoidance. Awareness of the transitory nature of one’s momentary experience is thought to lead to a change in the perspective on the self.53

The hypotheses of this study were that traumatized women in the yoga condition would show a clinically significant reduction in PTSD symptoms at posttreatment compared with a control group receiving weekly women’s health education, as well as demonstrate more improvement on affect regulation measures.


Following institutional board review, women 18–58 years old with chronic, treatment nonresponsive PTSD

were recruited via newspaper and radio ads, our website, and solicitation from mental health professionals. Trauma history was obtained by self-report. Treatment unresponsiveness was determined by participants having had at least 3 years of prior therapy treatment that focused on the treatment of PTSD. After an initial telephone screening, subjects were assessed, and, if eligible, randomly assigned to either trauma-informed yoga classes or women’s health education classes, with each class lasting 1 hour each week for 10 weeks. Participants in the control condition were offered the option of attending 10 weeks of yoga classes free of charge after posttreatment evaluation. The study ran from 2008 through 2011. The study was registered on ClinicalTrials.gov (identifier: NCT00839813).

Participants A total of 101 participants were assessed at pretreatment

after giving written informed consent. Eighty-three participants (82%) met study criteria, and the remainder met study exclusionary criteria, as noted below, or failed to meet the DSM-IV diagnostic criteria for PTSD. Of the 83 participants, 7 (7%) withdrew consent prior to randomization and 12 (12%) withdrew consent prior to treatment; 64 (63%) were randomly assigned to treatment and formed the intention-to-treat (ITT) sample. Posttraumatic stress disorder was established based on the Clinician- Administered PTSD Scale (CAPS) using the CAPS > 45 scoring rules.54 Chronicity was based on meeting criteria for PTSD in relation to an index trauma that occurred at least 12 years prior to intake. Baseline participant information is contained in Table 1. Comorbid conditions were established with a semistructured interview, the Structured Clinical Interview for DSM-IV Axis I Disorders.55

Exclusion criteria included unstable medical condition, pregnancy or breastfeeding status, alcohol or substance abuse/dependence in the past 6 months, active suicide risk or life-threatening mutilation, 5 or more prior yoga sessions, and Global Assessment of Functioning (GAF) score < 40. Study participants were required to be engaged in ongoing supportive therapy and to continue whatever pharmacologic treatment they were receiving.

Treatments The yoga intervention offered 10 weeks of an hour-long

trauma-informed yoga class, incorporating the central elements of hatha yoga: breathing, postures, and meditation. The protocolized trauma-informed yoga program56 was created by certified yoga professionals with master’s- and doctoral-level degrees in psychology, with supervision from the principal investigators. Simple, noninterpretive language without metaphors is used. The program emphasizes curiosity about bodily sensations, in which self-inquiry is prominent, with the instructor using key words such as “notice” and “allow,” as well as invitational phrases such as “when you are ready” and “if you like.” Bodily control is practiced, such as making choices to modify a posture, to stay in a particular posture, or to let the posture go.

C lin

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■ This study showed that a 10-week, weekly yoga program can significantly reduce posttraumatic stress disorder (PTSD) symptoms in women with chronic treatment-resistant PTSD, compared with a supportive therapy group, with effect sizes comparable to well-researched psychotherapeutic and pharmacologic approaches.

■ Current mainstream treatments of PTSD are informed by cognitive and pharmacologic models, as opposed to somatic regulation and interoceptive awareness. However, loss of body awareness, including alexithymia and loss of affect regulation is thought to play a significant role in the pathology of PTSD, which involves changes in physical self-awareness and alterations in the neural structures that register bodily states.

■ Body awareness is a n