Complementary and integrative interventions for PTSD

ABSTRACT

To treat the impact of trauma, most current evidence supports the use of trauma-focused psychotherapy as the first line approach. However, millions of individuals exposed to trauma worldwide seek Complementary and Integrative Health (CIH) therapies in hopes of achieving wellness above and beyond reducing symptoms. But what is the evidence for CIH interventions? What are potential pitfalls? Given the growing popularity of and strong interest in CIH, EJPT is featuring research on these approaches in this special issue. The papers range from common interventions such as mindfulness to the use of service dogs and scuba diving to alleviate trauma related symptoms. A featured editorial highlights the importance of defining when, where, and how placebo responses work. Nonspecific elements of treatment such as positive expectations, therapeutic rituals, healing symbols, and social interactions are identified as factors influencing treatment response and scientists looking to add to the CIH evidence base are encouraged to consider the impact and methodological challenges these elements present. CIH interventions more specifically recognize and harness some of these factors in addition to intervention-specific factors such as attention or emotion regulation along with focus on overall wellbeing. The body of work in this special issue supports the emerging evidence for meditative and relaxation-based interventions and illustrates a creative but nascent state of the field. Cross-intervention mechanisms that may play a role in achieving wellness, such as arousal reduction, emotion regulation, posttraumatic growth, and positive affect are highlighted. The trauma field would benefit from accumulation of evidence for promising CIH interventions, evaluation of potential mechanisms, and examination of health and wellbeing outcomes. With the paucity of high-quality trials, it would be premature to recommend CIH interventions as first-line treatments. However, the emerging literature on CIH continues to advance our understanding of what works and how these interventions exert their effects.

HIGHLIGHTS

• Complementary and Integrative Health (CIH) interventions for trauma that target holistic wellness above and beyond symptom reduction are increasingly used in the real world, though the evidence base lags.

• Papers in this issue support the emerging evidence for efficacy of mindfulness or other meditative or relaxation-based interventions.

• This special issue illustrates creative approaches but also the need for continued research establishing efficacy, evaluating more inclusive outcomes (e.g. a sense of wellbeing or ability to pursue valued life goals), and identifying potential mechanisms.

Para tratar el impacto del trauma, la mayoría de la evidencia actual respalda el uso de psicoterapia centrada en el trauma como enfoque de primera línea. Sin embargo, millones de personas expuestas a traumas en todo el mundo buscan terapias de salud complementaria e integradora (CIH en su sigla en inglés) con la esperanza de lograr un bienestar que vaya más allá de la reducción de los síntomas. Pero ¿cuál es la evidencia para las intervenciones de CIH? ¿Cuáles son los posibles peligros? Dada la creciente popularidad y el gran interés en los CIH, EJPT presenta investigaciones sobre estos enfoques en este número especial. Los artículos abarcan desde intervenciones comunes como la atención plena hasta el uso de perros de servicio y el buceo para aliviar los síntomas relacionados con el trauma. Una editorial presentada destaca la importancia de definir cuándo, dónde y cómo funcionan las respuestas placebo. Los elementos inespecíficos del tratamiento, como las expectativas positivas, los rituales terapéuticos, los símbolos curativos y las interacciones sociales, se identifican como factores que influyen en la respuesta al tratamiento y se invita a los científicos que buscan aumentar la base de evidencia de CIH a considerar el impacto y los desafíos metodológicos que presentan estos elementos. Las intervenciones de CIH reconocen y aprovechan más específicamente algunos de estos factores, además de factores específicos de la intervención, como la atención o la regulación de las emociones, junto con un enfoque en el bienestar general. El conjunto de trabajos de este número especial respalda la evidencia emergente a favor de las intervenciones basadas en la meditación y la relajación e ilustra un estado creativo pero incipiente del campo. Se destacan los mecanismos de intervención cruzada que pueden desempeñar un papel en el logro del bienestar, como la reducción de la activación, la regulación de las emociones, el crecimiento postraumático y el afecto positivo. El campo del trauma se beneficiaría de la acumulación de evidencia para intervenciones CIH prometedoras, de la evaluación de mecanismos potenciales y el examen de los resultados de salud y bienestar. Dada la escasez de ensayos de alta calidad, sería prematuro recomendar las intervenciones de CIH como tratamientos de primera línea. Sin embargo, la literatura emergente sobre CIH continúa avazando en nuestra comprensión sobre qué funciona y cómo estas intervenciones ejercen sus efectos.

为了治疗创伤的影响，大多数当前证据支持使用创伤聚焦心理治疗作为一线方法。然而，全世界数百万创伤暴露者寻求补充和综合健康 (CIH) 疗法，希望在减轻症状的基础上实现身心健康。但是 CIH 干预的证据是什么？ 潜在的隐患是什么？ 鉴于 CIH 的日益普及和浓厚兴趣，EJPT 在本期特刊中重点介绍了这些方法的研究。 这些论文的范围从常见的干预措施（例如正念）到使用服务犬和水肺潜水来减轻创伤相关症状。一篇专题社论强调了定义安慰剂反应何时、何地以及如何发挥作用的重要性。积极期望、治疗仪式、治疗符号和社交互动等治疗的非特异性元素被确定为影响治疗反应的因素，鼓励希望添加到 CIH 实证基础的科学家考虑这些元素带来的影响和方法学挑战。 CIH 干预措施除了特定于干预措施的因素（例如注意力或情绪调节以及对整体身心健康的关注）之外，更具体地识别和利用其中一些因素。 本期特刊中的工作主体支持了基于冥想和放松干预措施的新证据，并说明了该领域富有创造性但仍是新生阶段。 强调了可能在实现身心健康方面发挥作用的交叉干预机制，例如减少唤起、情绪调节、创伤后成长和积极影响。 创伤领域将受益于对有前景的 CIH 干预措施、潜在机制评估以及健康和幸福感结果考查证据的积累。 由于缺乏高质量的试验，推荐 CIH 干预作为一线治疗还为时过早。 然而，关于 CIH 的新兴文献继续增进我们对哪些干预措施有效以及这些干预措施如何发挥作用的理解。

KEYWORDS:

• Trauma
• PTSD
• interventions
• complementary
• alternative
• integrative
• meditation
• mind–body
• service animals
• mechanisms of action

PALABRAS CLAVE:

• Trauma
• TEPT
• intervenciones
• complementario
• alternativa
• integradora
• meditación
• mente-cuerpo
• animales de servicio
• mecanismos de acción

关键词:

• 创伤
• PTSD
• 干预措施
• 补充
• 替代性的
• 综合的
• 冥想
• 身心
• 服务性动物
• 作用机制

1. Introduction

Clinical guidelines for the treatment of posttraumatic stress symptoms overwhelmingly recommend cognitive–behavioural trauma-focused treatments delivered as ‘talk therapies’ (Bisson et al., 2019; Bisson & Olff, 2021; Department of Veterans Affairs and Department of Defense (VA/DoD), 2023; Hamblen et al., 2019). However, these are not a panacea. For populations in poorly resourced countries with limited health care infrastructure, these treatments cannot be scaled up easily to respond to the many in need (Bröcker et al., 2022; Kaminer et al., 2023; Schnurr et al., 2017). Even among those privileged to attain these treatments, success rates are modest and a substantial proportion of individuals either drop out, do not attain clinically significant gains, or are left with notable residual symptoms (Miles et al., 2022; Niles et al., 2018; Schottenbauer et al., 2008; Steenkamp et al., 2015; Thimm et al., 2020). Worldwide, trauma-exposed individuals are unlikely to receive these evidence-based psychotherapies because of the lack of a trained mental health workforce; complementary and integrative health (CIH) approaches may be more available to the extent that they can be delivered by less highly trained community-based providers (Magruder et al., 2017). Use of these interventions has expanded in ‘Western culture’ and this approach aligns with the shift in health care away from disease orientation towards prevention, wellbeing, and whole person orientation (Holmberg et al., 2012). Prominent examples of this shift are the implementation of the US Department Veteran Affairs (DVA) Healthcare System whole health transformation (Kligler et al., 2022) and the view of the World Health Organization (WHO) that ‘In an ideal world, traditional and complementary medicine would be offered together by a well-functioning, people-centred health system that balances curative services with preventive care’ (WHO, 2019, p. 5).

1.1. Complementary, alternative and integrative interventions

Complementary interventions are considered as adjuncts or supplements to conventional medical and psychological practices; these therapies complement conventional treatments rather than replace them. By contrast, alternative interventions are utilized in place of mainstream treatment. Some alternative approaches have sparked controversy and have been justifiably criticized for causing harm by drawing people away from known effective treatments. Integrative health is a newer term that encompasses traditional evidence-based therapies and newer nonconventional interventions and is becoming more broadly accepted worldwide (Boon et al., 2016). Integrative care often combines a variety of approaches to address not only physical or psychiatric symptoms but also the emotional, social, and spiritual aspects of a person's well-being (Boon et al., 2016). In this issue, we address the evidence for the efficacy and effectiveness of CIH and the hypothesized mechanisms by which they decrease PTSD symptoms or improve functioning.

2. In this issue

In this special issue, we have collected 21 papers. A brief summary of the articles is provided in Table 1. The series opens with a contribution by Benedetti et al. (2018) ‘How do placebos work?,’ which challenges the thinking that placebos are inert interventions. ‘Clinical trials are only aimed at establishing whether the patients who take the true treatment are better off than those who take the placebo, whereas the neurosciences want to understand what is going on in the patient’s brain when a placebo is given, i.e. when a therapeutic ritual is performed’ (p. 1). The evidence-based therapies for PTSD focus on the theorized underlying roots, such as intrusive trauma-related memories and maladaptive cognitions. CIH interventions have often been misunderstood as purely palliative or attributable to expectancies due to lack of understanding about their mechanisms of action. As Benedetti et al. note, in the psychosocial context, nonspecific elements of treatment such as positive expectations, therapeutic rituals, healing symbols, and social interactions are powerful factors influencing treatment response. CIH interventions frequently recognize and harness these important factors in addition to more traditionally-targeted mechanisms such as attention or emotion regulation along with focus on overall wellbeing and the whole person – both mind and body. We briefly discuss the papers below.

Table 1. Articles included in special issue ‘Complementary and Integrative Interventions for PTSD’.

Authors	Title	Summary
Editorial
Benedetti et al. (2018)	How do placebos work?	Placebo response in PTSD trials is high (19-62%) and should be conceptualized to include ‘the whole ritual of the therapeutic act.’ Placebos activate many of the same biopathways as drugs via ‘positive expectations, therapeutic rituals, healing symbols, and social interactions.’ Characteristics such as optimism/pessimism, suggestibility, empathy, neuroticism and catastrophizing also play into placebo response. Placebo effects are worthy of scientific inquiry to understand the biological underpinnings.
General Reviews
Bisson et al. (2020)	Non-pharmacological and non-psychological approaches to the treatment of PTSD: results of a systematic review and meta-analyses	Current evidence does not support offering non-pharmacologic and non-psychological interventions routinely for PTSD, but some provide alternatives with few side effects for people who do not respond to, do not tolerate, or do not want evidence-based interventions. More research to determine mechanisms of action is needed.
Michael et al. (2019)	Do adjuvant interventions improve treatment outcome in adult patients with posttraumatic stress disorder receiving trauma-focused psychotherapy? A systematic review	It is not possible currently to formulate evidence-based clinical recommendations regarding adjuvant interventions. While several hold the potential to boost the effectiveness of trauma-focused psychotherapy, sufficiently powered studies are necessary to separate plausible ideas from interventions proven to work in practice.
Purnell et al. (2021)	Reintegration interventions for CPTSD: a systematic review	Research on interventions to enhance integration in a phase-based approach for treatment of Complex PTSD is still in its infancy. Connection with others was the most reported benefit in the qualitative data reviewed.
Meditation and Relaxation
Crawford et al. (2019)	Targeting hyperarousal: mantram repetition program for PTSD in US veterans	Mantram repetition appears efficacious in reducing hyperarousal, and thereby impacting other PTSD symptom clusters, as one pathway to facilitating recovery.
Malaktaris et al. (2022)	Higher frequency of mantram repetition practice is associated with enhanced clinical benefits	Frequency of mantram repetition practice was associated with reductions in symptoms and improvements in well-being. Strategies to improve behavioural uptake may optimize the impact of the intervention.
Gibert et al. (2022)	Comparing meditative scuba diving versus multisport activities to improve posttraumatic stress disorder symptoms: a pilot, randomized controlled clinical trial	Intrusion symptoms were significantly improved by meditative scuba diving at one month, but faded after 3 months. The improvement in overall PTSD symptoms was not significantly different from the multisport programme.
Zhang et al. (2022)	Effectiveness of a nurse-led mindfulness-based Tai Chi Chuan (MTCC) in breast cancer survivors	Nurse-led MTCC increased the level of posttraumatic growth in breast cancer survivors. Effects persisted 1 year after intervention.
Beck et al. (2021)	Music therapy was noninferior to verbal standard treatment of traumatized refugees in mental health care: results from a randomized clinical trial	Compared to standard psychological treatment, music therapy for PTSD was similarly effective in this randomized clinical trial with 74 adult traumatized refugees. Significant changes improvements in wellbeing and dissociation were found at the six-month follow-up.
Knaust et al. (2022)	Nature videos for PTSD: protocol for a mixed-methods feasibility study	This randomized controlled feasibility study will examine whether 360-degree immersive nature videos on a head-mounted display or PC screen will be superior to nature sounds only for promoting relaxation for military personnel with posttraumatic stress disorder.
Animal assisted
van Houtert et al. (2018)	The study of service dogs for veterans with posttraumatic stress disorder – a scoping literature review	Though there are ample anecdotal reports of benefit, there is insufficient evidence to conclude that service dogs are an effective complementary treatment for veterans with PTSD. Additionally, the lack standardization and knowledge regarding animal welfare creates risks for both human and animal welfare.
Hediger et al. (2021)	Effectiveness of animal-assisted interventions for children and adults with posttraumatic stress disorder symptoms: a systematic review and meta-analysis	Animal-assisted interventions were found to be efficacious in reducing symptoms of PTSD and depression, but high-quality research is lacking.
Maoz et al. (2021)	Dog training alleviates PTSD symptomatology by emotional and attentional regulation	One year of dog training was associated with lower PTSD and depression symptoms and improved emotional and attentional regulation for adolescents with PTSD. However, dog–human interaction resulted in elevating the dogs’ anxiety and decreasing selective attention.
Nieforth et al. (2022)	Posttraumatic stress disorder service dogs and the wellbeing of veteran families	PTSD service dogs may provide both benefits and challenges for veteran families–higher caregiver burden, lower caregiver satisfaction, but allowing spouses to participate in more activities on average.
Body-Focused Immersive Approaches
Kuhfuß et al. (2021)	Somatic experiencing – effectiveness and key factors of a body-oriented trauma therapy: a scoping literature review	There is preliminary evidence that SE is an effective treatment of PSTD-related symptoms (affective and somatic symptoms and well-being) in both traumatized and non-traumatized samples. Risk of bias is high and the overall study quality is mixed.
Andersen et al. (2020)	Somatic experiencing for patients with low back pain and comorbid posttraumatic stress Symptoms – a Randomized Controlled Trial	A physiotherapeutic intervention with somatic experiencing (SE) was compared to the same intervention without SE for patients with pain-related disability and comorbid PTSD symptoms. Both groups achieved significant symptom reductions, but there were no significant group differences in outcomes.
Schäflein et al. (2018)	The enemy in the mirror: Self-perception-induced stress results in dissociation of psychological and physiological responses in patients with dissociative disorder	Compared to healthy controls, patients with dissociative disorders reported more subjective stress and dissociative symptoms while looking at their own faces in a mirror. Self-perception may be an important target for therapy.
Lifestyle factors
Wang et al. (2023)	Relationship between physical activity and individual mental health after traumatic events: a systematic review	Regular physical activity following traumatic events was associated with better well-being and fewer psychological symptoms. Physical activity may also buffer against symptom development and help maintain physical and mental health.
Escarfulleri et al. (2021)	Emotion regulation and the association between PTSD, diet, and exercise: a longitudinal evaluation among US military veterans	Trauma exposure and PTSD contributed to worse diet quality, though not to exercise habits. Consumption of unhealthy food may be driven by efforts to suppress emotion.
Mechanisms
Boelen (2021)	Dampening of positive affect is associated with posttraumatic stress following stressful life events	Dysregulation of positive affect (PA) has been rarely examined. Dampening of PA was associated with posttraumatic stress symptoms variance beyond neuroticism and regulation of negative affect.
An et al. (2018)	Dispositional mindfulness mediates the relationships of parental attachment to posttraumatic stress disorder and academic burnout in adolescents following the Yancheng tornado	In adolescents exposed to trauma, dispositional mindfulness partially mediated the relationship between parental attachment and (a) PTSD severity and (b) academic burnout. The protective factor of dispositional mindfulness may be built in the context of strong parent–child relationships.

2.1. General reviews

Three reviews in this issue provide a broad overview of the extant evidence for several CIH interventions and indicate that the evidence base holds promise but remains limited. Bisson et al. (2020) examined standalone interventions in the paper ‘Non-pharmacological and non-psychological approaches to the treatment of PTSD: Results of a systematic review and meta-analyses.’ Consistent with the US Departments of Veterans Affairs and Defense 2023 Clinical Practice Guideline (Department of Veterans Affairs and Department of Defense (VA/DoD), 2023), the authors concluded that it would be premature to recommend these CIH interventions as first-line treatments. Nonetheless, six interventions in the review reached a standard of ‘emerging evidence,’ including acupuncture, neurofeedback, Saikokeishikankyoto (a traditional Japanese herbal formula), somatic experiencing, transcranial magnetic stimulation (TMS), and yoga.

In most published studies of CIH interventions for PTSD, standalone CIH interventions are compared against evidence-based treatments for PTSD resulting in a dearth of information about the benefits and drawbacks of combining approaches. However, two reviews included here evaluate interventions used in integrative care. To address the issue of whether trauma-focused treatments can be boosted by complementary interventions, Michael et al. (2019) conducted the systematic review ‘Do adjuvant interventions improve treatment outcome in adult patients with posttraumatic stress disorder receiving trauma-focused psychotherapy?’ They concluded that although several of these interventions are promising, no evidence-based recommendations can currently be made. The review by (Purnell et al., 2021) on reintegration interventions for Complex PTSD examined what type of interventions might be effective in the third, reintegration phase in the treatment of Complex PTSD, such as yoga, exercise, use of service dogs, residential treatment, education, self-defense and patient research involvement. Similarly, although some reintegration interventions may reduce symptoms, the evidence is weak. All three reviews note that the methodological rigour of the studies was quite varied but generally low, with high risk for bias. CIH researchers should focus on conducting and describing their studies with a high level of rigour in order to impact clinical recommendations.

2.2. Meditation and relaxation

Mindfulness interventions comprised the largest body of evidence in the Bisson et al. (2020) review, and this series includes six papers on a variety of interventions with strong meditative or relaxation components that target arousal: mantram repetition, tai chi, scuba, music, and immersive nature videos. Previous research has shown that PTSD hyperarousal symptoms are more resistant to change than other symptom clusters following evidence-based treatments (Miles et al., 2022) and may be central in the maintenance of the disorder (Doron-LaMarca et al., 2015; Ruggero et al., 2021; Schell et al., 2004).

Crawford et al. (2019) examined the role of hyperarousal in ‘Targeting hyperarousal: mantram repetition programme for PTSD in US veterans.’ Mantram Repetition programme is a meditative practice featuring silent repetition of a spiritual word combined with one-pointed attention and slowing down. The authors’ finding that this programme reduced hyperarousal symptoms, thereby impacting other PTSD symptom clusters underscores a potentially important complementary use of arousal-reducing techniques.

The Malaktaris et al. (2022) paper ‘Higher frequency of mantram repetition practice is associated with enhanced clinical benefits,’ examined the issues of uptake of the practice and dose received. The result that higher frequency of meditation practice was associated with greater improvements in symptoms and wellbeing suggests that increasing the dose of meditation by utilizing strategies to monitor and encourage home practice is likely important to promote best outcomes. It may ultimately be useful to augment CIH practices with strategies to enhance behavioural uptake to optimize patient outcomes (Masheder et al., 2020).

A mindfulness-based tai chi programme was shown to increase posttraumatic growth in ‘Effectiveness of a nurse-led mindfulness-based Tai Chi Chuan (MTCC) programme on posttraumatic growth and perceived stress and anxiety of breast cancer survivors’ by Zhang et al. (2022). By contrast, a meditative scuba diving programme showed some initial advantage over a multisport programme on intrusion symptoms of PTSD, but no significant lasting differences were found in the Gibert et al. (2022) ‘Comparing meditative scuba diving versus multisport activities to improve posttraumatic stress disorder symptoms: A pilot, randomized controlled clinical trial.’

Beck et al. (2021) investigated a trauma-focused music and imagery intervention delivered by music therapists in ‘Music therapy was noninferior to verbal standard treatment of traumatized refugees in mental health care: results from a randomized clinical trial.’ With some similarities to mindfulness-based and exposure therapies, this intervention aimed to first decrease arousal with slow calming music, then to gradually introduce increasingly emotionally evocative music. The results were positive and similar to the comparison, a more standard psychological treatment.

Immersion in a virtual natural environment is under investigation in the feasibility protocol presented by Knaust et al. (2022) ‘Nature videos for PTSD: protocol for a mixed-methods feasibility study.’ The investigators will compare two types of immersive software for 360-degree videos and different lengths of immersion in them to inform whether the experience will enable beneficial relaxation levels for military personnel with PTSD. Identification of a sufficient or optimal dose of the intervention will contribute to determining whether it is feasible to scale up delivery to large numbers of individuals in military settings.

2.3. Animal-assisted therapies

Providing service animals to traumatized individuals to help them cope with symptoms has garnered a great deal of popular attention and in the United States has led to passage of the PAWS (Puppies Assisting Wounded Servicemembers) Act in 2021 (https://www.congress.gov/bill/117th-congress/house-bill/1022/text) to implement a pilot programme to provide service dogs and canine training for veterans with PTSD. Yet animal-assisted intervention research brings unique challenges in terms of understanding placebo/expectancy effects, achieving methodological rigour, and examining impact beyond the individual to both the animal and the owner’s interpersonal context. Two papers in the series indicate that the evidence for animal-assisted therapies for PTSD to date is mixed. A review by Hediger et al. (2021) ‘Effectiveness of animal-assisted interventions for children and adults with posttraumatic stress disorder symptoms: a systematic review and meta-analysis’ suggests that this approach may hold promise. However, the van Houtert et al. (2018) paper that focused more specifically on dogs for veterans ‘The Study of service dogs for veterans with posttraumatic stress disorder – a scoping literature review,’ found insufficient evidence to conclude that service dogs are an efficacious intervention for veterans with PTSD. They also noted that studies are varied and there is no clear agreement on specific added values and tasks of service dogs. Maoz et al. (2021) noted that dog training may reduce symptoms in ‘Dog training alleviates PTSD symptomatology by emotional and attentional regulation,’ finding a reduction in PTSD symptoms related to increased regulation over one year for the adolescent participants.

Impact on family was examined in the Nieforth et al. (2022) study ‘Posttraumatic stress disorder service dogs and the wellbeing of veteran families.’ The service dog intervention resulted in higher burden and lower satisfaction for caregivers, though it did allow spouses to participate in more activities. van Houtert et al. (2018) cautioned that there are potential risks to both the animals and their human families due to lack of standardized training for both. Maoz et al. (2021) found that in contrast to the humans’ positive responses to the dogs, the dogs’ anxiety increased and focused attention decreased. Thus, consideration of impact on the animals and families as well as specification of the tasks provided by the dogs will be important for future research in this area.

2.4. Body-Focused immersive approaches

The generally approachable and non-threatening meditative and animal-assisted interventions presented above share a quality of fostering present-moment awareness and reducing arousal. They may improve mood and enhance coping skills and set the stage to allow subsequent psychological growth in areas such as trauma processing, exposure through behavioural activation, or enhanced social support. By contrast, some treatments with a trauma exposure focus are experienced as more challenging and, therefore, associated with high attrition (Lewis et al., 2020). Somatic experiencing is a body-oriented approach that aims to change the physical response by focusing on visceral and musculoskeletal sensations. A scoping review by Kuhfuß et al. (2021) ‘Somatic experiencing – effectiveness and key factors of a body-oriented trauma therapy: A scoping literature review’ acknowledges that the limited number of studies to date are of mixed quality. They conclude that preliminary evidence indicates positive impact on affective and somatic symptoms and wellbeing in both trauma-exposed and non-trauma-exposed samples. In Andersen et al. (2020) ‘Somatic experiencing for patients with low back pain and comorbid posttraumatic stress symptoms – a randomised controlled trial,’ however, there was no advantage to outcomes when somatic experiencing was added to a physiotherapeutic intervention for pain. It is notable that both groups achieved reductions in pain disability and a small reduction in PTSD symptoms, underscoring that interventions impacting physical symptoms can also affect PTSD.

Schäflein et al. (2018) used facial mirror exposure and captured the reactions of their patients in ‘The enemy in the mirror: Self-perception-induced stress results in dissociation of psychological and physiological responses in patients with dissociative disorder.’ Patients with dissociative disorders as compared to healthy controls reported more subjective stress and dissociative symptoms while looking at their own faces in a mirror. The authors recommend therapeutic approaches promoting self-perception and self-compassion, in particular by using facial mirror exposure.

2.5. Lifestyle factors

Two papers in this series focus on the impact of diet and exercise on post trauma functioning. Physical activity and its relation to psychological functioning was the focus of a review by (Wang et al., 2023) entitled ‘Relationship between physical activity and individual mental health after traumatic events: a systematic review’. They concluded that regular physical activity can be a protective factor against the development of symptoms as well as improve mental health functioning following exposure to traumatic events. Escarfulleri et al. (2021) suggest a possible pathway by which lifestyle factors impact emotion regulation in ‘Emotion regulation and the association between PTSD, diet, and exercise: A longitudinal evaluation among US military veterans.’ They found that PTSD symptoms were associated with poor diet quality and that people with worse PTSD symptoms may eat poor-quality food as a way to suppress emotion. Not only may diet and exercise reduce PTSD symptoms and improve health, but the emotion regulation skills cultivated through lifestyle habits may support one’s ability to tolerate challenging treatments.

2.6. Mechanisms of action

To identify the mechanisms that drive symptom improvement, researchers are encouraged to examine and repeatedly measure constructs of hypothesized relevance. This was the focus of two papers in this series. Boelen (2021) examined the role of positive affect in ‘Dampening of positive affect is associated with posttraumatic stress following stressful life events.’ Standard evidence-based treatments for PTSD work to reduce negative affect by targeting negative thoughts, feelings, and memories with less attention given to the diminished positive affect that accompanies PTSD. This paper suggests dysregulation of positive affect as a potential mechanism that maintains symptoms and concludes that increasing positive affect may be useful in the treatment of PTSD. CIH interventions that promote savouring of positive experiences may be particularly helpful in terms of recapturing, promoting, and enhancing regulation of positive emotions.

In ‘Dispositional mindfulness mediates the relationships of parental attachment to posttraumatic stress disorder and academic burnout in adolescents following the Yancheng tornado,’ An et al. (2018) found dispositional mindfulness to be a protective factor for PTSD and academic burnout, mediating the impact of parental attachment. Boosting positive affect and mindfulness may directly or indirectly impact the development and maintenance of PTSD symptoms. In addition, such interventions might enhance coping for individuals who do develop PTSD to enable them to tolerate challenging treatments.

3. Conclusions

The papers in this series make important contributions to the emerging literature on CIH interventions for PTSD. Though the field continues to be marked by a paucity of high-quality trials and ‘real world’ application (e.g. complementary use), important advancements have been made in expanding how we consider and define treatment outcomes and success. Rather than a narrow focus on symptom reduction, research on CIH interventions has led to a more holistic approach that includes outcomes such as a sense of wellbeing or ability to pursue valued life goals. We encourage continued research to evaluate important outcomes such as posttraumatic growth, wellbeing, and positive emotion.

Evidence-based psychotherapies that require delivery by proficient clinicians are limited in how many individuals can access them given the resources of time and training they require. Mantram repetition, tai chi, nature videos, music therapy, and physical activity are some examples of interventions reported in this series that can address practical hurdles to dissemination, such as cost and accessibility. Treatments such as these that may be delivered in group settings with minimal requirements for specialized mental health training or customized equipment have the potential for greater reach. Also, in low and middle income countries with less specialized health care these types of interventions may be more feasible (Bröcker et al., 2022). In the Schnurr et al. (2017) paper that identified evolving perspectives in the field, Bryant noted ‘One public health approach is to try to implement evidence-based interventions that can be delivered to large numbers of affected people by non-specialist providers, even if it means that the effect size of treatment may not be as large as we would expect to see in a trauma-focused therapy delivered by expert specialists’ (p. 3). Answering the need for broad dissemination by evaluating internet-based trainings or peer-led interventions is another issue that we ask scientists in this area to address.

Attention to personal preferences, collaborative care, and emotional wellbeing are hallmarks of the prevailing patient-centred approach to healthcare. The meditative and animal-assisted interventions presented in this series are appealing and may be preferred to recommended evidence-based therapies for PTSD. Although personal choice and shared decision making are important considerations, there is valid concern that some experimental CIH therapies may be promoted as attractive alternatives to established evidence-based treatments and divert individuals from standard effective treatments. However, preliminary evidence suggests that use of CIH may increase the likelihood of subsequent engagement with evidence-based practices (Etingen et al., 2023). To reduce the risk that individuals are sidetracked from seeking effective treatment, integrating CIH approaches in comprehensive treatment plans is recommended. As Rizzo commented ‘I have come to think that we need to spend more time offering a variety of treatment options to patients, some in the complementary and alternative medicine domain that, while not rock-solid in terms of multiple independent randomized clinical trials, may connect individuals to the concept of healing’ (Schnurr et al., 2017, p. 4). Approachable and appealing CIH treatments may promote personal agency and engage individuals in the ‘ritual of the therapeutic act’ (Benedetti et al., 2018). They can serve as a ‘foot in the door’ to engage individuals with the healthcare system, develop trust with healthcare providers, increase openness to considering other treatments, and facilitate future engagement in healthcare.

Given the potential contribution of CIH to improving functioning and wellbeing for people exposed to trauma, it is critical that researchers focus on conducting methodologically rigorous studies. By assessing complements and adjuncts to known effective therapies, continued rigorous research of CIH interventions can contribute to answering the call from Schnurr et al. (2017) to enhance existing treatments to ‘make more people more better’ (p. 2). Longitudinal studies that track constructs such as some that were examined in this series of papers (e.g. hyperarousal, positive affect, and trait mindfulness) can help to identify key components of effective treatments. There is also a need to amass a body of evidence to support promising general approaches as opposed to developing new specialized interventions. Maybe even more important in this field will be to follow the principles of Open Science, such as preregistration of research and adherence to FAIR data principles (Boeckhout et al., 2017; Kassam-Adams & Olff, 2020; Olff, 2022). Integration of traditional and creative new approaches can be optimized by adhering to the WHO (2019) recommendation to ‘look not only at the many differences between the two systems, but also at areas where both converge to help tackle the unique health challenges of the 21st century’ (p. 5).

Disclosure statement

No potential conflict of interest was reported by the author(s).