PTSD and complex PTSD, current treatments and debates: a review of reviews

Abstract

Introduction

The National Institute for Health and Care Excellence guidelines for post-traumatic stress disorder (PTSD) were published in 2018, based on research up until that point. In this review, we summarize the current state of the evidence and discuss the findings of systematic reviews and meta-analyses published between 2019 and 2024.

Sources of data

We include peer-reviewed systematic reviews and meta-analyses published within the last 5 years.

Areas of agreement

Reviews and meta-analyses continue to support the efficacy, and cost-effectiveness, of trauma-focused psychological interventions, particularly Trauma-Focused Cognitive-Behavioural Therapy and Eye Movement Desensitization and Reprocessing.

Areas of controversy

Despite their demonstrated efficacy, dropout rates from psychological interventions for PTSD remain high. There has also been a rapid proliferation of research into novel interventions for treating PTSD. However, much of this research is of low quality and lacks head-to-head comparisons with established interventions.

Growing points

Novel methods of delivery of established treatments are being developed, including using virtual reality, intensive forms of treatment, and digital and remote methods of delivery.

Areas timely for developing research

More qualitative research to explore recipients’ experiences of interventions. More good-quality research and head-to-head comparisons of treatments.

Introduction

In this review, we will provide a brief background to the concepts of post-traumatic stress disorder (PTSD) and complex post-traumatic stress disorder (CPTSD). We will outline the current established clinical guidelines in the UK and highlight potential gaps in this guidance. We will then draw on evidence from systematic reviews published in the last 5 years to provide an overview of current evidence for different treatment approaches. Throughout, we present and discuss some of the current debates and recent developments in this field.

Methodology

We gathered evidence for this review by systematically searching PubMed, Medline, and the Cochrane Library for systematic reviews related to the treatment of PTSD and CPTSD in working age adults, published in peer-reviewed academic journals in the last 5 years. Searches were completed up until 25 July 2024. The searches were made up of derivations of key terms relating to ‘PTSD’, ‘CPTSD’, ‘treatment’, and ‘systematic review’ and were limited to papers published in English. A full list of search terms can be found in Supplementary Data.

References were uploaded onto EndNote to facilitate de-duplication and screening. We included articles which were systematic reviews specifically focused on the treatment of PTSD/CPTSD in working age adults. All psychological, social, pharmacological, physiological, and physical interventions were included. Systematic reviews which focused solely or predominantly on children or older adults were excluded, as were reviews which focused on a specific population, such as serving or veteran military personnel, refugees and asylum seekers, and those with significant comorbid conditions such as PTSD and psychosis, or PTSD and physical health issues. Reference lists of all included articles were hand searched to identify other potentially relevant reviews.

We retrieved 298 articles from initial searches. After screening, 54 were identified as eligible for inclusion in this review. A table providing information about all the systematic reviews included in this review can be found in the Supplementary Material. We have also drawn on other key papers from leading authors in the field of psychological trauma.

Post-traumatic stress disorder

The diagnosis of PTSD was first included in the DSM-III in 1980 [1] but had long been recognized as a disorder by many names, including ‘shell shock,’ ‘Vietnam syndrome’, and ‘battered woman syndrome’ [2]. Much early writing on the recognition and treatment of PTSD took place in military contexts, leading to the common (and enduring) misconception that PTSD is something experienced exclusively by those who have been exposed to military combat.

PTSD was initially controversial in its inclusion in the nosology of the DSM-III, as it stipulated that the ‘disorder’ had to be caused by an external aetiological agent, a ‘trauma’, rather than being attributable to individual pathology. In the DSM-III, a ‘trauma’ was defined as a ‘recognisable stressor that would evoke significant symptoms of distress in almost everyone’. In the DSM-III TR in 1987, this was further clarified to be a traumatic stressor that was ‘outside of the range of usual human experience’ [3]. PTSD remains unique amongst psychiatric diagnoses in requiring exposure to a specific event in order for a diagnosis to be made. Similarly, the requirement for the traumatic stressor to be extreme or outside of normal experience has persisted, despite some debate that PTSD could, or should, potentially be diagnosable to any subjectively distressing personal event.

Since its initial incarnation in the DSM-III, the diagnosis of PTSD has gone through many iterations. In the DSM-IV in 1994 [4], the criteria that the person’s response to the event must involve intense fear, helplessness, or horror was added, and this was retained in the DSM-IV-TR in 2000 [5]. In the DSM-V published in 2013 [6], this was then omitted, largely in response to the recognition that not all responses to trauma were fear based, and also commonly included emotions such as shame, anger, and disgust [7].

The conceptualization of PTSD in the current version of the DSM-5-TR published in 2022 [8] has changed little since the DSM-V in 2013. Currently, for a diagnosis of PTSD to be made according to DSM criteria, an individual must have been exposed to one or more traumatic events involving actual or threatened death, serious injury, or sexual violence. Exposure may involve directly experiencing the traumatic event, witnessing the event happening to others, learning that the event occurred to a family member or a close friend, or through indirect exposure in the course of occupational duties [8]. A diagnosis of PTSD may then be made when the individual reports the presence of four core symptoms; intrusions, avoidance, negative alterations in mood and cognition, and increased arousal or reactivity. These symptoms must have persisted for >1 month and cause clinically significant distress or functional impairment in order for a diagnosis to be given [8]. The DSM-V and DSM-V-TR allow for a subtype of dissociative PTSD, but notably do not include a diagnosis of Complex PTSD.

The International Classification for Diseases 11th edition (ICD-11) [9] offers a slightly different conceptualization of PTSD. For an ICD-11 diagnosis of PTSD to be made, an individual must have been exposed to ‘an extremely threatening or horrific event or series of events’ and be experiencing difficulties in three core symptom clusters; re-experiencing, avoidance of traumatic reminders, and hyperarousal [9]. As with DSM-V-TR criteria [8], symptoms must have persisted for several weeks and cause significant impairment in personal, family, social, educational, occupational, or other important areas of functioning [9].

The prevalence of population exposure to trauma is high, with global epidemiological surveys suggesting that 70.4% of people will be exposed to at least one traumatic event in their lifetime [10]. However, whilst rates of exposure to trauma in the general population may be high, conversion rates for developing PTSD are relatively low, with most people recovering naturally over time [11]. Data from the World Health Organisation World Mental Health Survey suggests a global lifetime prevalence rate of PTSD of 5.6% amongst those exposed to trauma [12] although rates are potentially much higher with exposure to more pernicious traumas, in certain occupational groups, and in countries exposed to more war and conflict [13].

A number of measures of PTSD exist and are used in clinical practice and research settings. The most commonly used self-report measures in clinical practice include the Impact of Events Scale-Revised [14] and the PTSD Checklist for DSM-V [15]. The Clinician Administered PTSD Scale for DSM-V [16] is considered the gold-standard measure of PTSD for research and medico-legal assessments.

Complex post-traumatic stress disorder

Complex PTSD (CPTSD) was only formally recognized as a diagnosable disorder in the ICD-11 in 2018 [9]. Research in this field is therefore still relatively in its infancy. Nevertheless, clinically, the concepts of complex trauma and complex PTSD have long predated the inclusion of CPTSD in the ICD-11 [9].

In her seminal work on Trauma and Recovery in 1992, Judith Herman was the first to write about the concept of ‘complex trauma’ which she defined as prolonged and repeated trauma [17]. She argued for the conceptualization of a new syndrome, which she proposed to call ‘complex post-traumatic stress disorder’ [17].

Despite long held expectation that the nomenclature of complex PTSD would be included in the DSM, it is currently only included as a diagnosis in the ICD-11. Complex PTSD is defined as a separate sister diagnosis to PTSD, including the core symptoms of PTSD (re-experiencing, avoidance, and hyperarousal), alongside a triad of further difficulties including affect dysregulation, negative self-concept, and interpersonal disturbances [9].

Whilst exposure to complex trauma is associated with the development of CPTSD, research has shown that some people may meet the criteria for CPTSD following exposure to a single-incident trauma, and some people who have been exposed to complex trauma may only meet the diagnosis for PTSD [18]. Since its inclusion in the ICD-11 (WHO, 2018), research has suggested that CPTSD may actually be as equally prevalent as PTSD in the general population and more prevalent in treatment-seeking populations [19] and high-risk occupational groups [13, 20].

The main measure used to assess both PTSD and CPTSD according to ICD-11 (WHO, 2018) criteria is the International Trauma Questionnaire [21].

Current clinical guidance

The National Institute for Health and Care Excellence (NICE) guidelines on PTSD which were published in 2018 [22], and which extend previous 2005 Guidance, provide clear recommendations for the assessment and treatment of PTSD in children, young people, and adults in the UK.

NICE guidance [22] recommends the comprehensive assessment of people with PTSD, including assessment of physical, psychological, and social needs, as well as risk. Where people might be considered to be at high risk of developing PTSD, e.g. after a major disaster, NICE recommends that those co-ordinating the response should consider the routine use of validated brief screening tools for PTSD for at least 1 month after the disaster. For populations at particularly high risk of developing PTSD, such as refugees and asylum seekers, NICE recommends the routine use of a validated brief screening measure as part of a comprehensive physical and mental health screen. NICE Guidance makes clear that treatment for PTSD should not be delayed or withheld in cases where there are ongoing court proceedings or applications for compensation [22].

In cases of confirmed PTSD, or clinically important symptoms of PTSD, NICE recommends eight to twelve 90-min sessions of individual Trauma-Focused CBT (TF-CBT), within which Cognitive Processing Therapy, Cognitive Therapy for PTSD, Narrative Exposure Therapy (NET), and Prolonged Exposure therapy are included. NICE also supports the use of Eye Movement Desensitization and Reprocessing (EMDR) therapy if this is the client’s preference, although notably NICE currently does not recommend EMDR for combat-related trauma.

NICE does not endorse the use of drug treatments as a first-line intervention for PTSD, but suggests that an SSRI or venlafaxine could be considered in cases where the person prefers medication over psychological therapy. Based on the evidence available at the time, the NICE guidance committee concluded that medication is less effective, and less cost-effective, than psychological therapy in the treatment of PTSD.

When it comes to guidance on treating CPTSD, NICE guidance is a little more vague, although this is perhaps not surprising with limited evidence available when the guidance was published in 2018. For people with additional complexity or comorbidity, including those with CPTSD, NICE suggests increasing the number or duration of therapy sessions, taking into account the client’s safety and stability, helping the person to address any barriers to engaging with trauma-focused therapy such as dissociation, emotional dysregulation, interpersonal difficulties or negative self-perception, and working with the person to plan any ongoing support that they might need after treatment to manage any residual PTSD symptoms or ongoing comorbidities [22].

Predating the inclusion of CPTSD in the diagnostic nomenclature, in 2012 the International Society for Traumatic Stress Studies (ISTSS) [23] published expert consensus guidance, with 84% of 50 expert trauma clinicians advocating for a phase-based approach to treating CPTSD. This sequential approach comprised three phases: phase 1, stabilization focused on ensuring the person’s safety, reducing symptoms, and increasing resources; phase 2, trauma memory processing; and phase 3, reintegration involving consolidation of treatment gains to enable transition from therapy to greater engagement in relationships, work, education, and community life. There has since been debate about the necessity of a dedicated stabilization phase for CPTSD (see below) with critics arguing that it may delay, or prevent, clients with CPTSD from accessing trauma memory processing. The ISTSS have since revised their guidance to suggest that a more personalized approach to treatment may be appropriate, rather than necessarily adopting a sequential phased-based approach [24].

Individual psychological interventions for PTSD

Evidence from systematic reviews, meta-analyses, and meta-syntheses published in the last 5 years has been consistent in continuing to support the efficacy of specific trauma-focused individual psychological therapies in the treatment of PTSD.

Reviews published in this time period have provided further evidence of the clinical effectiveness of Trauma-Focused Cognitive Behaviour Therapies (TF-CBT) [25] as well evidence of their cost-effectiveness [26]. Specifically, Cognitive Processing Therapy [25, 27], Cognitive Therapy [25], and Prolonged Exposure [25] have been shown to be efficacious, with large effect sizes and good long-term outcomes [28]. The efficacy of EMDR has also continued to be supported in recent reviews [25, 29] as has the effectiveness of NET [25, 30, 31]. However, there is not to date sufficient evidence to support the use of Supportive Counselling, Group Interpersonal Therapy, Group Supportive Counselling, Psychodynamic Therapy, Relaxation Training, Psychoeducation [25], or Present-Centred Therapy [32].

In the last 5 years, there has also been some preliminary evidence emerging for other novel psychological interventions, such as CBT without a trauma focus [25], Writing Therapy [33], and Emotional Freedom Techniques [34]. Although notably, trauma-focused CBT interventions and EMDR have demonstrated the strongest effect sizes across reviews [25].

Many studies included in all these reviews do, however, have methodological limitations noted by the review authors. Furthermore, many of the included studies have compared psychological interventions with inactive waiting list control conditions, with few head-to-head trials of established trauma-focused therapies.

One review and meta-analysis did consider eight trials which directly compared EMDR and TF-CBT [35]. The review demonstrated that EMDR and TF-CBT were equally effective in reducing PTSD symptoms. The authors highlighted that at the end of treatment, three studies provided some evidence of lower depression symptom scores in the EMDR group, and three other studies showed lower anxiety symptom scores in the EMDR group. However, there were no significant differences in symptoms of PTSD, depression, and anxiety between EMDR and TF-CBT at 3- and 6-month follow-ups [35]. Another systematic review and meta-analysis of 15 RCTs found no significant differences between EMDR and other trauma-focused psychological treatments in reducing PTSD symptom severity and dropout rates [36].

One review including seven trials explored whether different psychological therapies had differential impact on the DSM-5 PTSD symptom clusters (re-experiencing, avoidance, negative alterations in cognitions and mood, and hyperarousal) but found that all psychological interventions (including Exposure Therapy, Cognitive Processing Therapy, and EMDR), irrespective of whether they had a more cognitive or behavioural focus, had similar efficacy in treating all four PTSD symptom clusters [37]. The authors of this review concluded that these evidence-based psychotherapies for PTSD promote a cascade of improvement, supporting the network theory of PTSD symptoms [37].

Two systematic reviews published in the last 5 years have explored client-related factors associated with better and worse outcomes in psychological therapies for PTSD. In a systematic review including 126 RCTs, characteristics associated with more positive outcomes in psychological treatments for PTSD included higher education levels, adherence to homework, and more recent trauma. Characteristics associated with less positive outcomes were more severe PTSD symptoms prior to treatment and comorbid depression [38]. In another review including 11 studies (including 6 focused on military populations and 5 on civilians), comorbid depression, anxiety, and alcohol abuse were the strongest predictors of poor therapeutic response, with older age, combat exposure, social support, and hyperarousal also being moderate predictors [39].

Another systematic review and meta-analysis looked specifically at how the therapeutic alliance in psychological therapy for PTSD affected outcomes. The review found that therapeutic alliance did significantly predict PTSD outcomes with a medium effect size [40].

Despite their demonstrated efficacy, reviews of trauma-focused psychological interventions have also demonstrated high rates of dropout, with one meta-analysis of 115 RCTs finding a pooled rate of dropout from RCTs of psychological therapies for PTSD of 16% (95% CI 14–18%) [41]. Another meta-analysis of 85 trials found that the mean dropout rate from guideline-recommended treatments for PTSD was 20.9% (95% CI 17.2–24.9) [42].

Two systematic reviews published in this time frame have synthesized qualitative research exploring patients’ experiences of trauma-focused psychological therapy. In one review of nine qualitative studies, participants across all studies were noted to report high levels of distress, citing feeling overwhelmed, finding that trauma-focused therapy was life-consuming, and reporting initial worsening of symptoms such as nightmares, flashbacks, and intrusive thoughts [43]. Nonetheless, discussing their trauma was deemed essential by most participants and specific trauma-focused aspects of therapy were credited for therapeutic progress. Many participants in the included studies admitted considering dropping out of therapy, although most continued. Reasons for considering discontinuing included ambivalence about treatment, difficulty tolerating exposure, and avoidance. Support from family and friends, the therapeutic alliance, and perceived progress were cited as reasons for continuing [43].

Another review of five qualitative papers explored recipients’ experiences of EMDR [44]. The review authors described how core ‘transformational’ change was reported by participants in four of their included studies, helping them to make cognitive and behavioural changes to come to terms with the past. Personal motivators and self-care were cited as necessary conditions for EMDR to effect change, as was feeling safe, which was influenced by both the therapeutic relationship and positive attitudes and optimism of the treating team [44].

Individual psychological interventions for CPTSD

A review and meta-analysis including 51 RCTs explored the impact of established evidence-based psychological interventions for PTSD on the additional triad of symptoms in CPTSD (affect dysregulation, negative self-concept, and interpersonal disturbances) [45]. The review found that for trial participants with CPTSD, TF-CBT, exposure alone, and EMDR were effective (compared to usual care) in treating symptoms of PTSD, and they also had moderate-large or large effect sizes on negative self-concept, and moderate or moderate-large effect sizes on interpersonal relationships. Few trials, however, reported data on affect dysregulation [45]. The findings of this review would suggest that trauma-memory processing interventions may have significant impact not only on PTSD symptoms, but also on some of the additional difficulties associated with a CPTSD diagnosis.

One meta-review including 24 meta-analyses aimed to provide an overview of the efficacy of individual psychological therapy for participants with CPTSD or samples considered at risk of complex traumatization [46]. The review authors concluded that good-quality empirical evidence did exist for established psychotherapies with this population, but noted that the quality of included meta-analyses varied. It was further concluded that more research was needed to explore the efficacy of these psychological interventions specifically for people with CPTSD [46].

A systematic review including 12 studies explicitly explored the question of whether phase-based interventions were superior to single-phase (trauma memory processing alone) interventions for CPTSD [47]. The findings of the review suggested that phase-based treatments were effective, and in some cases, significantly more so than single-phase interventions. The impact of Phase 1 (stabilization) on Phase 2 outcomes was mixed, however, leading the review authors to conclude that the two phases may impact different outcomes [47]. Another systematic review and network meta-analysis of 116 studies also explored psychological interventions for PTSD and comorbid mental health problems following complex trauma [48]. The authors of this review concluded that psychological therapy has a beneficial impact on PTSD, anxiety, depression, and sleep in people with a history of complex trauma, and that multicomponent interventions, which could include phase-based approaches, were most effective in managing PTSD in the context of complex trauma [48]. Notably, neither of these reviews included any research evaluating Phase 3 (reintegration) interventions.

Only one systematic review published to date has examined the impact of Phase 3 (reintegration) interventions on CPTSD [49]. The review included 15 studies of miscellaneous designs, with a variety of interventions including exercise, yoga, education, residential treatment, self-defence, involvement in research, and use of service dogs. Quantitative findings were mixed, with some studies reporting significant improvements in symptoms of PTSD, functioning, and additional difficulties associated with CPTSD, although the review authors noted that overall study quality ratings were low. Qualitative findings from eight of the included studies suggested that reintegration interventions were valued by participants, with the facilitation of connection with others being the most commonly reported benefit [49].

Group psychological interventions

Group-based interventions are not currently included in the NICE Guidance for PTSD [22]. However, emerging evidence does provide some support for group-based CBT with a trauma focus in the treatment of PTSD symptoms [25]. Another review and meta-analysis of group-based treatment for adults with symptoms of CPTSD found that trauma memory processing in a group setting was significantly more effective than treatment as usual, with large effect sizes on symptoms of PTSD, depression, and psychological distress [50]. However, direct comparisons with non–trauma-focused group treatments were inconclusive [50].

Couple and family interventions

We found four systematic reviews exploring interventions with couples and families. This body of research provides some preliminary evidence that the involvement of significant others in psychological treatment can improve both patient-related PTSD symptoms as well as partner/family outcomes [51–54]. Interventions which involved more active participation from significant others seemed to be more effective than those with more passive involvement [52].

Digital and remote interventions

The last 5 years has seen a proliferation of research, catalysed by the COVID-19 pandemic, on digital and remote interventions. Approaches examined included smartphone-based apps, internet-delivered interventions, and video-telephone conferencing.

Taken together, this body of literature suggests good feasibility and acceptability of smartphone apps and digital interventions for PTSD and CPTSD but with mixed findings in terms of effectiveness [55–65].

Reviews of remote video- or telephone-based methods of therapy delivery indicate that telehealth may have similar efficacy to in-person therapy [66–68]. In-person interventions may still be preferable for some client groups, e.g. those with comorbid depression [66].

Barriers to implementation noted across studies included technological barriers, necessity of a good internet connection, lack of personal connection, and limited uptake in lower- and middle-income countries. Some reviews cited better outcomes for interventions which also included elements of therapist support [55, 58].

Intensive treatment

We found one review of 11 studies of intensive variants of evidence-based psychological therapies for PTSD [69]. The authors of this review note that study findings demonstrated a large impact of intensive treatment on the reduction of PTSD symptoms, with high rates of treatment completion. The authors concluded that intensive delivery of psychological interventions could be an effective alternative to standard (typically weekly) approaches, with improved treatment response and lower dropout.

Virtual reality exposure therapy

Interesting recent developments in virtual reality and associated research is reflected in three reviews and meta-analyses which have been published in this area in the last 5 years [70–72]. All three reviews provide evidence for the efficacy of virtual reality exposure therapy for symptoms of PTSD when compared with inactive waitlist controls [70–72], with benefits maintained over time [70].

Notably, all the reviews showed that effect sizes were much smaller when compared to other active treatments, leading these review authors to conclude that virtual reality exposure therapy was better than waitlist controls and potentially as effective as other established psychotherapies. However, the authors also note that the quality of included studies varied, with a predominance of male and military samples. The economic costs and acceptability of virtual reality treatments are also not discussed.

Psychopharmacology

Despite medication not being recommended as a first-line intervention in NICE guidance (NICE 2018), numerous trials have continued to explore whether common psychiatric medications may be effective in treating PTSD, either as standalone interventions or in conjunction with psychological therapy. Overall, this body of research suggests low to medium effect sizes for pharmacological monotherapy [73–76] and mixed results as to whether medication may augment psychological therapy [75, 77, 78]. When pharmacological and psychological interventions have been compared, reviews have continued to demonstrate that psychological interventions were more effective [48, 79], more cost-effective [26], had longer lasting benefits [79], and that pharmacological interventions were associated with more adverse events [76].

Other reviews have explored the application of medications typically prescribed for physical health issues. Rivastigmine is a cholinesterase inhibitor, typically used in the treatment of Parkinson’s and Alzheimer’s disease to improve mental function. In a systematic review including four studies investigating the impact of Rivastigmine on treatment-refractory PTSD, the review authors cited some positive findings on self-report measures from case studies and an open trial, but noted included study designs were weak, and no significant difference was found when Rivastigmine was compared with placebo or treatment as usual in an RCT [80].

Prazosin is an alpha blocker typically used to treat high blood pressure or an enlarged prostate by relaxing blood vessels so blood flows more easily. Prazosin has also been used for nightmares related to PTSD. In a meta-analysis of six studies, findings showed that prazosin was associated with improved PTSD symptoms, sleep quality, and nightmares in some studies; however, the largest trial included in the meta-analysis found a large placebo effect, particularly for nightmares, leading the review authors to conclude there was no evident treatment difference [75].

Another review examined 14 RCTs which had used intranasal oxytocin as a potential therapeutic agent in treating PTSD [81]. The findings of the review suggested that intranasal oxytocin could be a safe pharmacological intervention with a hypothesized mechanism of effect being in facilitating social and goal-oriented cognition and behaviour, which would impact positively on the therapeutic alliance and thereby promote better treatment outcomes in psychological therapy. However, the review authors also note methodological limitations of the included studies and mixed findings, leading them to conclude that the evidence was currently not sufficient to quantify the effectiveness of this intervention.

There has also been a surge in research exploring the application of psychoactive substances in the treatment of PTSD. Research into the use of cannabinoids from three reviews including a variety of study designs has shown that the use of medical cannabis may reduce PTSD symptoms, reduce anxiety, and improve sleep [82–84]. However, the authors of these reviews also point out that there is currently limited evidence of their safety and efficacy.

We found five systematic reviews and meta-analyses which explored the use of MDMA-assisted psychotherapy [75,85–88]. MDMA is a psychedelic that increases mood, energy, and feelings of connection, and the rationale for its addition alongside psychotherapy is that it will allow therapists to probe trauma memories with less emotional distress for clients, potentially expediting treatment. Each of the reviews reported moderate to large effect sizes in reducing PTSD symptomatology with MDMA-assisted psychotherapy. However, all of the reviews also pointed out methodological limitations in the literature, including small sample sizes, issues with blinding, and publication bias, suggesting very low certainly of evidence. Of greater concern, all of the reviews also highlighted serious adverse side effects associated with MDMA-assisted psychotherapy, including muscle tightness, jaw clenching, headaches, anxiety, low mood, nausea, and loss of appetite [75,85–88]. Critically, in 2024 the US Food and Drug Administration declined approval for the use of MDMA in the treatment of PTSD, requesting further trials to address methodological limitations and safety concerns.

We also found five systematic reviews and meta-analyses of ketamine use in the treatment of PTSD [89–93]. Ketamine has previously demonstrated some effectiveness in the reduction of depression and has since been explored as a treatment for PTSD. Four of the reviews reported statistically significant reductions on PTSD measures; however, most evidence of effect was only provided 24 h after administration, with few studies measuring long-term impact. One review concluded that the evidence for ketamine as a standalone treatment for PTSD was ‘very low’ and in combination with psychotherapy was ‘low’ [93]. Adverse side effects were also explored in one review [92] and noted to include dry mouth, dizziness, and blurred vision. Again, methodological limitations were noted by review authors, including small samples and high heterogeneity across analyses. Review authors concluded that more high-quality research is needed to ascertain the efficacy and safety of ketamine as a sole or adjunct treatment.

At the time of writing this review, no published systematic reviews have explicitly looked at psychopharmacology in the treatment of CPTSD. Some studies included criteria such as ‘treatment refractory PTSD’ which might be indicative of CPTSD presentations, but the effect on additional symptoms of CPTSD over and above PTSD had not been considered. Other studies in this new field may have been recently published, but have not yet been subject to systematic review.

Physiological interventions

Some reviews have explored evidence for physiological interventions. Four reviews examined non-invasive brain stimulation (NIBS), including different variants of transcranial magnetic stimulation or transcranial direct-current stimulation [94–97]. Taken together, these reviews provide evidence of some reduction in PTSD symptoms, although most trials compared NIBS to sham treatments and provided no information about intervention acceptability.

One systematic review and meta-analysis considered research on electroconvulsive therapy (ECT) and found a small but significant pooled effect of ECT on reducing PTSD symptoms [98]. However, this review only included five studies of low-quality designs and also did not explore intervention acceptability.

Two other reviews considered neurofeedback in the treatment of PTSD with review authors arguing that studies show some promising results, but acknowledging methodological limitations in the existing literature [99, 100].

One review looked at the use of polyunsaturated fatty acids (PUFAs) in the treatment of PTSD and found evidence from three preclinical studies of an increase in spatial learning and memory, but findings from three RCTs showed no significant effect of PUFAs in preventing PTSD [101].

One review explored research on the impact of hyperbaric oxygen therapy in treating PTSD; a body of research that has arisen after hyperbaric treatments for mild traumatic brain injury or post-concussion syndrome have shown simultaneous reductions in PTSD symptoms. Based on seven studies, the authors of this review argued that hyperbaric oxygen therapy has demonstrated significant reductions in PTSD symptoms, although they also note that the highest doses were associated with severe, albeit reversible, exacerbation of emotional distress in 30%–39% of participants [102]. This body of literature does not consider the acceptability of this intervention, nor does it discuss possible mechanisms of effect.

Music and light therapy

Two recently published reviews have explored music therapy [103] and light therapy [104]. Both reviews demonstrated some benefits in treatment groups when compared to inactive controls, but the authors of both reviews acknowledge methodological issues with current research resulting in low levels of certainty in this evidence.

Physical exercise and mind–body interventions

A number of reviews have been published in the last 5 years which have explored exercise and mind–body interventions for PTSD. One review and meta-analysis of 11 RCTs found a beneficial impact of physical exercise on PTSD symptoms as well as depression, quality of life, substance misuse, and sleep [105]. Another review and meta-analysis including 29 studies of mixed designs noted significant reductions in PTSD symptomatology from body and movement-oriented interventions, as well as moderate improvements in depression and sleep [106]. One other review noted preliminary evidence that exercise in combination with TF-CBT could have an adjuvant effect on PTSD symptoms [107].

Two reviews have specifically explored mindfulness and yoga [108] and Tai Chi and Qigong [109]. Both noted some demonstrated effectiveness of these interventions on trauma-related symptoms with high rates of satisfaction and further benefits noticed in relaxation, other mental health symptoms, pain, and cognitive functioning [109]. One other systematic review of 26 RCTs explored mind–body interventions (MBIs) more broadly, finding that such interventions may be effective in improving PTSD symptoms in some individuals [110]. However, it was noted that findings were mixed for different types of MBIs, and that the strength of the evidence was generally low to moderate.

Such findings have led the authors of these reviews to conclude that exercise and mind–body interventions may provide a useful adjunct to established evidence-based treatments for PTSD. However, much research in this field is noted to be of variable quality with few rigorous research trials. More research with head-to-head comparisons of established treatments with and without exercise/mind–body interventions as an adjunct is warranted.

Strengths and limitations

Whilst we have included systematic reviews, meta-analysis, and meta-syntheses published within the last 5 years, the original empirical studies contained within them may date back some years. Therefore, we cannot conclude that this review of reviews necessarily offers the most up-to-date evidence on treatments for PTSD and CPTSD. As noted by many of the authors of the reviews included in this paper, much of the original empirical research in this field may be subject to methodological limitations, is of varying quality, and lacks head-to-head comparisons with active interventions.

This review article may also be subject to some limitations. Whilst we endeavoured to systematically search for relevant reviews on two large-scale databases and the Cochrane database, as well as hand searching reference lists of included studies, we may still have missed reviews relevant to this topic. Other potentially relevant papers, which have not yet been included in a systematic review, have not been considered here. Nevertheless, we hope this summary provides a useful overview for the reader and may serve to signpost to further reading.

We also excluded reviews which focused on specific populations, such as military samples, refugees, and asylum seekers, or comorbid presentations with PTSD. The interventions discussed in this paper may need to be adapted for these populations, and there will be specific reviews exploring the needs of these groups which are outside the remit of this paper but to which the interested reader should refer.

Conclusions

There is continuing evidence for the efficacy of trauma-focused psychological therapies as a frontline approach to treating PTSD. The strongest evidence continues to be for trauma-focused CBT and EMDR, although there is emerging evidence for other individual, group, and remotely delivered psychological therapies. There is less research into adapting treatments for CPTSD, which is an area for further future research.

Despite their demonstrated efficacy, dropout rates from trauma-focused psychological therapies remain high. There has also been a proliferation of research into novel interventions in the treatment of PTSD, either as alternatives or as adjuncts to trauma-focused psychological therapies. Much of this research, however, is of poor quality and notably lacks comparisons with established evidence-based interventions for PTSD.

More qualitative research is needed to explore recipients’ experiences of interventions, as well as more PPIE and co-production of interventions with those with lived experience of PTSD and CPTSD. More good-quality research into novel interventions is warranted, and more head-to-head comparisons of active treatments are needed.

Author contributions

Jo Billings (Conceptualization, Formal analysis, Methodology, Supervision, Writing—original draft) and Helen Nicholls (Data curation, Methodology, Writing—review & editing)

Conflict of interest: None declared.

Funding

None declared.

Data availability

No new data were generated or analysed in support of this review.