Abstract
Objectives.
To (1) characterize complementary and alternative medicine studies for posttraumatic stress disorder symptoms, (2) evaluate the quality of these studies, and (3) systematically grade the scientific evidence for individual CAM modalities for posttraumatic stress disorder.
Design.
Systematic review. Eight data sources were searched. Selection criteria included any study design assessing posttraumatic stress disorder outcomes and any complementary and alternative medicine intervention. The body of evidence for each modality was assessed with the Natural Standard evidence-based, validated grading rationale.
Results and Conclusions.
Thirty-three studies (n = 1329) were reviewed. Scientific evidence of benefit for posttraumatic stress disorder was strong for repetitive transcranial magnetic stimulation and good for acupuncture, hypnotherapy, meditation, and visualization. Evidence was unclear or conflicting for biofeedback, relaxation, Emotional Freedom and Thought Field therapies, yoga, and natural products. Considerations for clinical applications and future research recommendations are discussed.
Introduction
Posttraumatic stress disorder is a serious and growing health issue. Approximately 7.7 million American adults (3.5%) have posttraumatic stress disorder in a given year. 1 Not only do people with posttraumatic stress disorder experience debilitating symptoms of posttraumatic stress disorder, but they also have a higher prevalence of other psychiatric and physical comorbid conditions such as depression. The annual economic burden of anxiety disorders in the United States is estimated at $42.3 to $46.6 billion. 2 The personal and societal costs of posttraumatic stress disorder are high because of chronic symptoms, increased comorbidities, and marked functional impairment. 3 – 5
Posttraumatic stress disorder may occur when a person has been exposed to a traumatic event that involves actual or threatened death, serious injury, or threat to the physical integrity of self or others. People who acquire posttraumatic stress disorder after a traumatic event experience a constellation of symptoms that were not present before the trauma. Symptoms fall into 4 diagnostic criteria: intrusion, avoidance, negative alterations in cognitions and mood, and alterations in arousal and reactivity. People with posttraumatic stress disorder persistently reexperience the trauma through recurrent and intrusive distressing recollections of the event, and they may experience severe distress when exposed to cues that symbolize or resemble aspects of the trauma. They also avoid thoughts, feelings, conversations, people, places, or activities that are reminiscent of the initial event. People with posttraumatic stress disorder can have negative alterations in cognition or mood criteria such as the inability to recall key features of the traumatic event, persistent negative beliefs and expectations about oneself or the world, and markedly diminished interest in significant activities. They also have altered arousal and reactivity symptoms such as hypervigilance, difficulty concentrating, difficulty falling or staying asleep, irritability or outbursts of anger, or exaggerated startle response. 6
The complex psychopathology and frequency of comorbid conditions often makes posttraumatic stress disorder difficult to treat. Trauma-focused psychotherapy has the strongest evidence for posttraumatic stress disorder treatment. 7 Yet, a high percentage of individuals do not engage in or drop out prematurely from these treatments because of chronic patterns of avoidance and an inability to tolerate the intense emotions often experienced with these approaches. 8 Avoidance behaviors may maintain posttraumatic stress disorder symptoms by interfering with the processing of traumatic memories and preventing habituation or relearning to conditioned stimuli. 9 Selective serotonin and serotonin-norepinephrine reuptake inhibitors also have strong evidence for posttraumatic stress disorder treatment; however, medication refusal and noncompliance are quite high in this population. 10 Thus, the evaluation of posttraumatic stress disorder treatments that could be used in conjunction with or as an alternative to existing therapies is warranted.
Complementary and alternative medicines may be beneficial for people with posttraumatic stress disorder. The National Institutes of Health, National Center for Complementary and Alternative Medicine defines complementary and alternative medicine as a group of diverse medical and health care systems, practices, and products that are not generally considered part of conventional medicine. 11 Complementary and alternative medicine therapies are attractive because they use an integrative approach to healing and usually do not report side effects. Most complementary and alternative medicine modalities engage the healing process without trauma recall, and are thus, not trauma-focused.
Many people with posttraumatic stress disorder currently use complementary and alternative medicine for their symptoms despite a lack of definitive evidence for their benefit. Thirty-eight percent of the 23 393 U.S. adults polled in a 2007 National Health Interview Survey used complementary and alternative medicine. Of these users, 2.8% reported using complementary and alternative medicine for anxiety symptoms or anxiety-related conditions, including posttraumatic stress disorder. 12 The most commonly used modalities were natural products, deep breathing, meditation, chiropractic, massage, yoga, diet-based therapies, progressive relaxation, guided imagery, and homeopathic treatment. Another survey of 1004 adults reported that 43% of respondents used complementary and alternative medicine for generalized anxiety disorder, panic disorder, social anxiety disorder, or posttraumatic stress disorder. Acupuncture, meditation/relaxation, biofeedback, chiropractic, massage, prayer, or spiritual practices were the most commonly used modalities, followed by dietary supplement and/or herbal medicine use. 13 Additionally, nearly 40% people with posttraumatic stress disorder surveyed within the Veterans Administration used complementary and alternative medicine to address emotional and mental problems. 14
Posttraumatic stress disorder is a serious and growing health concern without treatment that is acceptable to all people. Complementary and alternative medicine therapies may offer complementary and alternative therapies to existing treatments and people with posttraumatic stress disorder are already using them for their symptoms. However, the evidence of efficacy of complementary and alternative medicine for posttraumatic stress disorder is limited. To date, 2 systematic reviews have assessed the efficacy of complementary and alternative medicine for anxiety-related disorders, including posttraumatic stress disorder. One meta-analysis found that meditative therapies provided significant improvements in anxiety symptoms compared to controls. 15 This study only included 1 complementary and alternative medicine modality and was not specific for posttraumatic stress disorder. Another systematic review found very few complementary and alternative medicine–based randomized controlled trials for posttraumatic stress disorder using stringent inclusion/exclusion criteria and the authors were unable to make any conclusions about efficacy. 16
Building on this previous work, the purpose of this systematic review was to assess the state of the science of complementary and alternative medicine for posttraumatic stress disorder. The objectives of this systematic review were to (1) characterize complementary and alternative medicine studies where posttraumatic stress disorder outcomes were assessed, (2) evaluate the quality of these studies, and (3) systematically evaluate the evidence of complementary and alternative medicine for posttraumatic stress disorder symptoms. This study adds to the complementary and alternative medicine and posttraumatic stress disorder field by evaluating the efficacy of complementary and alternative medicine modalities for posttraumatic stress disorder with broader inclusion/exclusion criteria and therefore, describing a wider view of the research literature than previously done.
Methods
Literature Search Methods
Comprehensive searches were conducted by a research librarian using MEDLINE (1950 to March 12, 2013), PsycINFO (1967 to March 12, 2013), CINAHL (1982 to March 12, 2013), Alt HealthWatch (1984 to March 12, 2012), AMED (1980 to March 12, 2013), Cochrane Library: CENTRAL (March 12, 2013), Cochrane Database of Systematic Reviews (March 12, 2013), Database of Abstracts of Reviews of Effects (March 12, 2013), and Health Technology Assessment Database (March 12, 2013). Search terms included complementary and alternative medicine modalities and posttraumatic stress disorder terms dependent on the search strategy required for each database (the search strategy for MEDLINE is included as Supplemental Data). All peer-reviewed studies in any language were included.
Study Eligibility
Two reviewers independently screened titles and abstracts of all publications retrieved by the search strategies. Studies meeting the following inclusion criteria, and those with insufficient information to determine eligibility from the abstract, were selected for further review.
Study Design
Randomized controlled trials, nonrandomized controlled trials, crossover trials, prospective and retrospective observational studies with controls, case-control studies, and uncontrolled pre-post studies where the sample size was greater or equal to 5. Studies with intention-to-treat or completer analyses were included.
Types of Participants
Adults diagnosed with posttraumatic stress disorder and/or adult participants who were administered a measure assessing posttraumatic stress disorder symptoms.
Interventions
Any complementary and alternative medicine modality as described on the National Institutes of Health, National Center for Complementary and Alternative Medicine Web site at the time this review was planned (March 1, 2012), 11 including Natural Products (herbal medicines, botanical medicine, botanicals, vitamins, minerals, other “natural products,” dietary supplements, probiotics, fish oil); Mind-Body Medicine (meditation, yoga, deep-breathing exercises, guided imagery, hypnotherapy, progressive relaxation, qi gong, tai chi, biofeedback); Whole Medical Systems (acupuncture or traditional Chinese medicine, homeopathy, naturopathy, ayurvedic medicine); Manipulative and Body-Based Practices (spinal manipulation, chiropractic, osteopathy, massage); Movement Therapies (Feldenkrais method, Alexander technique, pilates, Rolfing Structural Integration, Trager psychophysical integration); Traditional/Spiritual Healing (shamanic healing, curandero); and Energy Medicine (magnet therapy, light therapy, biofields, applied qi gong, Reiki, healing touch, therapeutic touch). The interventions included were based solely on the National Center for Complementary and Alternative Medicine Web site at the time of study design rather than on the presence of a rationale or mechanism for each included complementary and alternative medicine modality and why it may or may not be appropriate for posttraumatic stress disorder. Cognitive behavioral therapy, prolonged exposure therapy, eye movement desensitization and reprocessing, imagery rehearsal and restructuring, journaling, or expressive writing studies were not included because they are used as evidenced-based standard care for posttraumatic stress disorder treatment. If one of these therapies was compared with a complementary and alternative medicine therapy directly, such as eye movement desensitization and reprocessing versus relaxation therapy, the study was included. If the therapy was multimodal, where it included cognitive behavioral therapy or prolonged exposure therapy in addition to some complementary and alternative medicine modalities such as relaxation or creative arts, it was excluded. Repetitive transcranial magnetic stimulation was included as a magnet therapy, and hypnotherapy and biofeedback were included as mind-body medicine therapies.
Outcome Measures
Each study had to include at least one measure assessing posttraumatic stress disorder symptoms such as intrusion, avoidance, negative alterations in cognitions and mood, and alterations in arousal and reactivity. Outcomes from any version of the
Data Extraction and Management
The following data were collected: study design, number of treatment arms, setting, participant description, inclusion and exclusion criteria, number of subjects, mean age, intervention type and description, attrition rate, home practice details (if any), group or individual practice, outcome, time points at which outcomes were measured,
Assessment of Methodological Quality
Each study was evaluated for risk of bias and methodological quality. Randomized controlled trials were evaluated with the Cochrane Risk of Bias Tool 17 and the Quality Assessment Tool. 17,18 Nonrandomized controlled trials studies were assessed for quality with the Quality Assessment Tool only since the Cochrane Risk of Bias Tool is specifically designed for randomized controlled trials. Two reviewers assessed the methodological quality of studies independently. A third reviewer resolved any disagreements through consensus.
Instruments Used to Assess Risk of Bias and Methodological Quality
The The
Data Synthesis and Evidence Grading
A meta-analysis for this study was not possible because of substantial variation in participant type, interventions, implementation, and outcomes across studies. Therefore, we sought to provide a general understanding of the available evidence for each modality. First, each study was rated as a positive, mixed, negative or neutral study (positive = most posttraumatic stress disorder outcomes are positive; mixed = only 1 to 2 posttraumatic stress disorder subscales are positive; negative = no posttraumatic stress disorder outcomes are positive; neutral = no difference between intervention and active control). Studies were then grouped by modalities. The level of evidence was then graded for each modality according to the Natural Standard evidence-based grading rationale. 20 Letter grades of A, B, C, D, and F reflect the level of scientific evidence in support of a given therapy for posttraumatic stress disorder (A = strong scientific evidence; B = good scientific evidence; C = unclear or conflicting scientific evidence; D = fair negative scientific evidence; F = strong negative scientific evidence; L = lack of evidence). The criteria to designate each grade are described in more detail in Table 1. Grades reflect the level of available scientific data for or against the use of each therapy for a specific medical condition. For example, to receive an A level of evidence a modality had to have statistically significant evidence of benefit from >2 properly conducted randomized controlled trials, OR evidence from one properly conducted randomized controlled trial AND one properly conducted meta-analysis, OR evidence from multiple randomized controlled trials with a clear majority of the properly conducted trials showing statistically significant evidence of benefit AND with supporting evidence in basic science, animal studies, or theory. Natural Standard was founded by health care providers and researchers to provide high-quality, evidence-based information about complementary and alternative medicine therapies.
Natural Standard Evidence-Based Validated Grading Rationale.
Results
Search Results
A total of 1596 studies were identified (Figure 1). After removing duplicates, 1337 titles and abstracts were screened for inclusion criteria. Ninety full-text articles were assessed for eligibility, and of these, 33 were included in the final review (Table 2).

Study flow diagram.
Characteristics of Included Studies.
Abbreviations: Acu, acupuncture; ADIS-R, Anxiety Disorders Interview Schedule–Revised; CAPS, Clinician-Administered PTSD Scale; CAPS-AN, Clinician-Administered PTSD Scale Avoidance/Numbing Subscale; CBT, cognitive behavioral therapy; CGI-I, Clinical Global Impression–Improvement; CGI-S, Clinical Global Impression–Severity; Ctrl, control group; Dec, decreased; Diff, difference; dlPFC, dorsolateral prefrontal cortex; DSM,
*These studies only provided gender characteristics for those who completed the trial.
**Criteria for determining overall study outcome: Positive = most PTSD outcomes showed statistically significant improvements, Mixed = only 1 to 2 PTSD subscales are significantly improved, Negative = no PTSD outcomes significantly improved, Neutral = both intervention and active control showed significant improvements, no difference between the groups. Two studies have 2 grades to account for comparisons between the active control and nonactive control groups. For example, Hollifield had a positive results compared to the waitlist (Positiveb) but a Neutral results compared with the active control because both active control groups had improvements from before to after the intervention. a = active control comparison; b = nonactive control comparison; c = no control.
Description of Included Studies
All articles were published between 1985 and 2012. Eighteen of the studies were conducted within the past 5 years (2008-2012). There were 17 randomized controlled trials, 4 nonrandomized controlled trials, 9 pre-post designs, and 3 crossover interventions. The mean sample size was 40 ± 38 (range 5-183). In total, 1329 participants were included. Of the controlled trials, 13 used active control groups (either another intervention or placebo intervention), 6 used nonactive controls (waitlist or treatment as usual), and 2 used active and nonactive controls. Eighteen studies confirmed posttraumatic stress disorder diagnosis of participants and 15 did not. Posttraumatic stress disorder diagnosis was confirmed using clinician assessed diagnostic criteria and/or through structured clinical interviews (
Methodological Quality of Included Studies
Methodological quality for all studies as determined by the Quality Assessment Tool is presented in Table 2. The mean score was mean 78 ± 9 (median 80, range 54-95). Several criteria were met by the majority of studies (at least 31 out of 33): the purpose of the study was stated, outcomes were validated and adequately described, the intervention was reasonable and appropriate to answer questions posed by researchers, intervention protocols were adequately described, participant demographic information was reported, and descriptive measures were identified for all important variables. Five studies reported a power calculation to determine adequate sample size. Blinding of participants or outcome assessors was discussed in 11 of the 24 controlled and cross-over design studies. Thirteen studies reported adverse events.
Table 3 summarizes the risk of bias for the 17 randomized controlled trials included in this review. Several of the studies failed to provide enough detail for adequate assessment; methods of random sequence generation and allocation concealment were particularly poorly reported. The repetitive transcranial magnetic stimulation studies and the nutraceutical studies used a sham or placebo control group that allowed for participant blinding. One study 21 assessed treatment credibility as it was perceived by the participants (ie, expectation). Nine of the studies explicitly stated that outcomes assessors were blinded to treatment group. In general, randomized controlled trial sample sizes were small (7 of the 17 randomized controlled trials had n < 33). Three studies performed intention-to-treat analyses. 22 –24
Summary of Risk of Bias for Randomized Controlled CAM Trials for PTSD.
Abbreviations: CAM, complementary and alternative medicine; PTSD, posttraumatic stress disorder; EFT, emotional freedom technique; rTMS, repetitive transcranial magnetic stimulation; N/A, not applicable; (
Quality of the Body of Evidence for Each Modality
The body of evidence for each modality for posttraumatic stress disorder was reviewed. Letter grades were derived for each modality using the Natural Standard evidence-based grading rationale. Table 1 describes the criterion for each grade. The individual study outcomes that determined the grades are listed in Table 2.
Repetitive Transcranial Magnetic Stimulation
Five trials (3 randomized controlled trials, 1 pre-post, and 1 crossover) were included. The randomized controlled trials were of generally high quality (Quality Assessment Tool scores ranging from 71 to 88) and all had positive results. Both the pre-post and crossover trials had lower quality ratings and showed mixed result.
Acupuncture
Two randomized controlled trials, both of which demonstrated significantly improved symptoms over control conditions were included. Hollifield et al
23
found that acupuncture was as effective as cognitive behavioral therapy when compared with a waitlist control, and Zhang et al
25
found that acupoint stimulation combined with cognitive behavioral therapy was more effective than cognitive behavioral therapy alone. Because these are slightly different modalities, further research is warranted.
Biofeedback
Four trials (1 randomized controlled trial, 1 nonrandomized controlled trial, and 2 pre-post studies) were included. The controlled trials had high Quality Assessment Tool scores, with either mixed results or no difference from the control group. The other studies had small sample sizes and methodological concerns.
Emotional Freedom Technique/Thought Field Therapy
The body of evidence for these mind-body techniques includes 1 randomized controlled trial showing no difference between Emotional Freedom Technique and Eye Movement Desensitization and Reprocessing, and 1 pre-post trial with positive results. While the noninferiority of Emotional Freedom Technique to Eye Movement Desensitization and Reprocessing is an intriguing finding, both trials had significant dropout rates (43% and 49%, respectively), bringing into question the validity of results.
Hypnotherapy
Three studies (2 randomized controlled trials and 1 pre-post) were included. Both randomized controlled trials had active control groups. In one study, the hypnotherapy group did just as well as the cognitive behavioral therapy group at a 3-year follow-up.
22
In the other study, the hypnotherapy group had significantly greater improved outcomes than Zolpidem.
26
The Zolpidem study was targeted at improving insomnia for people with posttraumatic stress disorder rather than posttraumatic stress disorder symptoms directly and Zopidem as a hypnotic pharmaceutical would not be expected to improve posttraumatic stress disorder symptoms. The grade remains the same if this study is excluded.
Meditation
Nine studies were included, 5 randomized controlled trials and 4 pre-post studies. Meditation represents the largest number of complementary and alternative medicine studies for any modality included in this review. All the pre-post studies showed positive outcomes and high Quality Assessment Tool scores (all >86). While the randomized controlled trials were of variable quality and sample size, the majority favored meditation over waitlist controls. Several different types of meditation were assessed and heterogeneity complicated the grading of this modality.
Relaxation
Four studies (2 randomized controlled trials, 1 pre-post, and 1 crossover) were included, 3 of which had significant methodological issues and showed mixed or negative results.
Visualization
One large, high-quality randomized controlled trial was included. This study combined healing touch with guided imagery and demonstrated significant improvements in posttraumatic stress disorder symptoms compared with treatment as usual.
Yoga Breath Work
One large nonrandomized controlled trial was included demonstrating that yoga breath work alone and in combination with exposure therapy is better than wait list for acute trauma survivors.
Natural Products
Two randomized controlled trials were included. One small randomized controlled trial showed no effect of inositol compared with placebo. Another small randomized controlled trial showed a positive effect of ginkgo biloba on posttraumatic stress disorder outcomes compared with placebo.
Grades were reassessed for 2 subgroups: (1) studies where posttraumatic stress disorder was required and (2) randomized controlled trials. These subgroup analyses are important because they reflect more stringent inclusion criteria and lend credibility to the application of these modalities under more specific circumstances. When evaluating only those studies where a posttraumatic stress disorder diagnosis was required, all grades remained the same except for 3 modalities. Meditation was reduced from a B to a C because only 1 out of the 9 meditation studies required a posttraumatic stress disorder diagnosis. Guided imagery and yoga breath work were downgraded to “lack of evidence” because neither of these studies required a posttraumatic stress disorder diagnosis. When evaluating only the randomized controlled trials, all grades remained the same except, again, yoga breath work was downgraded to “lack of evidence” because it did not include a randomized controlled trial.
Discussion
The objectives of this review were to systematically characterize and evaluate complementary and alternative medicine studies for posttraumatic stress disorder. We believe that at this relatively young stage of complementary and alternative medicine research it is important to evaluate all the available evidence for a particular modality, and inclusion criteria were deliberately kept broad to capture as many studies as possible. We found 33 complementary and alternative medicine studies that used 10 different modalities to assess posttraumatic stress disorder outcomes. Scientific evidence of benefit for posttraumatic stress was “strong” for repetitive transcranial magnetic stimulation, and “good” for acupuncture, hypnotherapy, meditation, and visualization. Evidence was “unclear or conflicting” for biofeedback, relaxation, Emotional Freedom and Thought Field therapies, yoga breath work, and natural products.
Implications for Research
Studies included in this review were of variable quality. Important aspects of rigorous research design were often not conducted or not reported. In order to improve the quality of the complementary and alternative medicine research field and accurately determine efficacy of complementary and alternative medicine modalities, investigators are encouraged to consider the following when designing studies: (1) choose an appropriate control (ie, active, nonactive, or both) depending on the research question 27 ; (2) assess for expectancy and placebo effects because they play a pivotal role in mind-body studies28,29; (3) blind research staff and participants if possible; (4) randomize participants; (5) clearly define the population being studied; (6) determine an appropriate sample size; and (7) follow standard rigorous clinical design and reporting guidelines. 30,31 This will help improve the quality of complementary and alternative medicine studies and thus the quality of evidence.
Overall Completeness and Applicability of Evidence
Studies in this review recruited from a variety of settings (eg, Veteran’s Administration facilities, outpatient clinics, prison) and countries (North America, Asia, Iran, and Israel). Participants were from the general population, combat veterans, firefighters, and sexual abuse survivors. Approximately one third of the studies were specific for combat-related trauma and another one third enrolled participants with a diverse mix of trauma exposure. Studies varied widely with respect to participant gender. Some studies enrolled only men, other studies only women, and several had a diverse mix of male and female participants. All-male studies most frequently targeted combat-related trauma whereas all-female studies more often addressed sexual abuse, thus reflecting gender differences associated with these trauma exposures. While the grades did not distinguish by trauma type or gender, the results lend preliminary support to the acceptability of complementary and alternative medicine for people with a variety of trauma exposures and genders. Additional research and synthesis of evidence is needed to address the efficacy of each modality by trauma exposure and gender.
Implications for Clinical Practice
There is positive evidence of effectiveness for repetitive transcranial magnetic stimulation, acupuncture, hypnotherapy, meditation, and visualization for the treatment of posttraumatic stress disorder symptoms. Repetitive transcranial magnetic stimulation had the strongest scientific evidence followed by acupuncture, hypnotherapy, meditation, and visualization. Practitioners may take this evidence into account when considering these complementary and alternative medicine modalities for treating patients with posttraumatic stress disorder symptoms.
Repetitive transcranial magnetic stimulation is a noninvasive and painless technique that directly stimulates cortical neurons and is approved by the Food and Drug Administration for the treatment of depression. 32 Transcranial magnetic stimulation induces significant changes on monoamine neurotransmitters and cortisol, neuroendocrine factors also affected in posttraumatic stress disorder. Future transcranial magnetic stimulation research would clarify dosing relationships to efficacy (ie, frequency used [low or high], area of brain treated, and timing and duration of sessions). Acupuncture is a Chinese medicine energy modality that uses needles inserted into specific points along the body’s energetic meridians. Acupuncture may help posttraumatic stress disorder through its effects on the autonomic nervous system and prefrontal and limbic brain structures, systems that are intrinsically involved in posttraumatic stress disorder pathophysiology. 23,33
Meditation also appears to be helpful for posttraumatic stress disorder. While there are various meditation styles, all types incorporate self-observation of mental activity, attention training, and cultivating an attitude that highlights process rather than content. 34 Meditation studies show positive benefit for a variety of symptoms related to posttraumatic stress disorder such as depressive symptoms or relapse, 35 –41 anxiety, 40,42 –45 suicidal behavior, 46 and sleep disturbances. 47,48 Meditation may affect posttraumatic stress disorder symptoms through attention training, improving prefrontal cortex activity and autonomic nervous system function, changing thought patterns, increasing emotional acceptance and reducing avoidance, and regulating the hypothalamic-pituitary-adrenal axis. 49
Hypnotherapy, another mind-body medicine, is a psychotherapeutic technique based on the hypnotist providing suggestions for changes in sensation, perception, cognition, affect, mood, or behavior. 50 Hypnotherapy may allow people with posttraumatic stress disorder to downregulate their autonomic nervous system and thus become more receptive to changes in cognition, mood, or behavior.
Similarly, visualization is designed specifically for the patient’s imagination (mind) to have an effect on a physiological system (body). Visualization is a lived experience that is a dynamic, quasi-real, psychophysiological process. 51 Guided imagery is a variation on visualization where another person leads an individual through experiences in the mind to access the physical, emotional and spiritual dimensions that effect physiological change, modulating the individual’s response. 52 Both hypnotherapy and visualization/guided imagery could be modified to specifically address the symptoms the person with posttraumatic stress disorder is experiencing.
At this point, the evidence is “unclear or conflicting” for biofeedback, Emotional Freedom and Thought Field Therapies, yoga breath work, relaxation, and natural products. Future studies are warranted to clarify results before practitioners should recommend them specifically for posttraumatic stress disorder symptoms.
Agreement and Disagreements With Other Studies or Reviews
Our work builds on a previous review conducted by Strauss et al 16 that found inconclusive evidence for all the complementary and alternative medicine modalities they assessed using very stringent inclusion and exclusion criteria. Similarly, we found inconclusive evidence for some modalities. However, because we included study designs other than randomized controlled trials, participants with posttraumatic stress disorder symptoms (and not just a posttraumatic stress disorder diagnosis), and used a different grading schema, we were able to present a broader view of the state of complementary and alternative medicine research. Our study was also different in that we included repetitive transcranial magnetic stimulation as a complementary and alternative medicine modality, evaluated natural products, and included non-English articles in our search criteria. While our overall search strategy was not as comprehensive, both reviews highlight the importance of improved complementary and alternative medicine clinical trial methods, more rigorous reporting, and the need for more randomized controlled trials in complementary and alternative medicine research.
Limitations
Various limitations must be considered when reviewing these results. Some modalities included in this review may not be considered complementary and alternative medicine modalities (eg, repetitive transcranial magnetic stimulation because of its psychiatry heritage; biofeedback because of its common use in mainstream academic medicine and clinical psychology; and hypnotherapy as a psychosocial treatment). For this study, we used the complementary and alternative medicine definition a priori as explained on the National Center for Complementary and Alternative Medicine Web site 11 at the time of designing the study. Those definitions included magnet therapy under the “Energy Medicine” category and hypnotherapy under the “Mind-Body Medicine” category. Repetitive transcranial magnetic stimulation, biofeedback, and hypnotherapy could also be included as complementary because they are not evidence-based standard care treatments for posttraumatic stress disorder, even though they may be considered conventional for other conditions.
Although we included all languages in our search strategy we only found English language articles. We searched only published articles; gray literature resources were not included and hand-searches of relevant bibliographies were not conducted. Publication bias is present when positive trials are more frequently published over negative studies. It is possible that this affected our review as we found 17 positive trials and 5 negative trials (7 neutral and 4 mixed). Another limitation is that we did not take into account outcome measure timing in our grading schema. For example, we were not able to distinguish if each modality had more or less evidence for posttraumatic stress disorder symptoms immediately after the treatment versus at a longer term follow-up. Additional studies with less heterogeneity in methods, participants and outcomes need to be conducted before rigorous meta-analyses can be done. Because of this, the results from this study must be viewed as qualitative trends rather than conclusions.
Conclusions
Several complementary and alternative medicine modalities may be helpful for improving posttraumatic stress disorder symptoms. Repetitive transcranial magnetic stimulation has the strongest evidence for benefit followed by acupuncture, hypnotherapy, meditation, and visualization. There is insufficient evidence to recommend biofeedback, Emotional Freedom and Thought Field Therapies, relaxation, yoga breath work, and natural products at this time. Future research should include larger, properly randomized, controlled trials with appropriately selected control groups and rigorous methodology.
Footnotes
Acknowledgments
The authors would like to thank Hannah Moshontz for her help with this project.
Author Contributions
HW designed the study, worked with librarian on literature searches, reviewed titles and abstracts, rated methodological quality, extracted data, analyzed data, and wrote the preliminary manuscript. AS rated methodological quality, extracted data, analyzed data, and wrote/edited the manuscript. RN rated methodological quality, extracted data, and edited the manuscript. JC rated methodological quality, extracted data, and edited the manuscript.
Authors’ Note
The content of this article is solely the responsibility of the authors and does not necessarily represent the official views of the National Institutes of Health.
Declaration of Conflicting Interests
The authors declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.
Funding
The authors disclosed receipt of the following financial support for the research, authorship and/or publication of this article: This work was supported by the National Center for Complementary and Alternative Medicine of the National Institutes of Health (Grant Nos. T32AT002688, K01AT004951, and K24AT005121) and the Agency for Healthcare Research Quality (Grant No. 5T32HS017582-05).
Ethical Approval
Since this was a systematic review that did not include any human research, no institutional review board approval was needed.
