An estimated 70% of the global population will be exposed to at least one potentially traumatic lifetime event, Reference Kessler, Aguilar-Gaxiola, Alonso, Benjet, Bromet and Cardoso1 a trend unlikely to decline given current political tensions and climate change projections indicating increased frequency and severity of disasters. 2 According to the DSM-5-TR, a traumatic event is defined as the exposure to actual or threatened death, serious injury or sexual violence, which may be experienced directly, witnessed or learned through the experience of a close other, or through repeated exposure in work settings (i.e. exposure to repeated details of violent incidents). 3 Such exposure may lead individuals to develop trauma- and stressor-related disorders (TSRD), 3 exacerbating systemic costs associated with increased healthcare utilisation, and making greater demands on social support systems. Reference Lowe, Blachman-Forshay, Koenen, Schnyder and Cloitre4,Reference Benedek, Stoddard, Benedek, Milad and Ursano5 Post-traumatic stress disorder (PTSD), the most widely studied TSRD, involves chronic and recurrent symptoms of intrusion, avoidance, negative changes in mood and cognition, and alterations in arousal that persist for at least 1 month following exposure to a traumatic stressor, defined as a direct or indirect threat to one’s life (DSM-5-TR). 3 If the symptoms are experienced for less than a month (i.e. not becoming chronic), acute stress disorder (ASD) would be diagnosed, 3 also referred to as acute PTSD. Reference Bryant6 In adjustment disorder (AjD), failure to adapt to a traumatic event or non-traumatic stressor causes distress and impairment within 3 months of the event, but symptoms typically resolve within 6 months, once the stressor or its consequences have terminated. 3 TSRDs encompass a range of responses to adversity, including PTSD, ASD, AjD and, more recently, prolonged grief disorder (PGD). However, given the distinct aetiological mechanisms and diagnostic criteria associated with PGD, Reference Killikelly and Maercker7 and in line with prior conceptual work on stress-response syndromes, Reference Maercker, Brewin, Bryant, Cloitre, Van Ommeren and Jones8 the present review focuses specifically on PTSD and AjD symptoms, which are most commonly examined together following diverse stressors. Reference Strain and Friedman9
With substantial attention and resources dedicated to understanding and treating PTSD in its chronic form, ASD and AjD have historically received less attention. Yet, AjD is one of the most common diagnoses in primary care, Reference Zelviene and Kazlauskas10 despite estimates indicating that only 1–2% of individuals who experience a stressful life event ever receive this diagnosis. Reference Casey, Maracy, Kelly, Lehtinen, Ayuso-Mateos and Dalgard11 Authors have suggested that these prevalence rates may have been underestimated because of a lack of clarity in diagnostic criteria based on previous versions of diagnostic manuals, such as the ICD-10 12 and the DSM-5. 13,Reference Bachem and Casey14 Nonetheless, trauma-focused interventions are considered first-line treatment approaches for both PTSD and related stress-response syndromes. Reference Casey and Strain15,Reference Baumeister, Bachem, Domhardt and Maercker16 They are increasingly delivered remotely because of barriers in access, such as lack of resources, stigma or limited trust in the healthcare system on the part of patients. Reference Smith, Workneh and Yaya17 For PTSD specifically, the critical need for effective treatment is met by trauma-focused cognitive–behavioural therapy (CBT) such as cognitive processing therapy (CPT) and prolonged exposure, both of which have strong empirical support. 18–Reference Cukor, Spitalnick, Difede, Rizzo and Rothbaum20 By contrast, no official intervention guidelines currently exist for AjD, as diagnostic criteria suggest that AjD tends to resolve itself. 3 However, emerging evidence supports the use of various psychological interventions for AjD, including CBT, mindfulness and psychodynamic approaches. Reference Bachem and Casey14,Reference ODonnell, Metcalf, Watson, Phelps and Varker21,Reference Constantin, Dinu, Rogozea, Burtea and Leasu22 Despite the availability of these interventions, many sociocultural and institutional barriers (e.g. stigma, lack of resources, timely access to interventions, lack of trust in the healthcare system) persist, Reference Smith, Workneh and Yaya17,Reference Kantor, Knefel and Lueger-Schuster23 particularly when treatments are offered in person. Reference Kantor, Knefel and Lueger-Schuster23 Given these challenges, this review focused on the feasibility and/or acceptability of trauma-related treatments for PTSD, ASD and AjD delivered remotely.
Remote and digital interventions for TSRDs
With increased availability of remotely delivered interventions, driven by the COVID-19 pandemic, many barriers may be overcome, or limited, while offering more access options for treatment-seeking individuals. Reference Figueroa and Aguilera24 Remote interventions, for instance, include mobile applications and internet-delivered modules or interventions with or without therapist involvement, Reference Rogers, Lemmen, Kramer, Mann and Chopra25 therapy delivered by video conferencing, which mimics face-to-face intervention, Reference Backhaus, Agha, Maglione, Repp, Ross and Zuest26 and even interventions delivered through other platforms, such as message-based platforms. Reference Berrouiguet, Baca-García, Brandt, Walter and Courtet27 According to Andersson, Reference Andersson28 important factors to consider in investigating remote and digital interventions include the platform used, assessment tools, content of the intervention (e.g. CBT, exposure), the involvement of a therapist and ethical guidelines. Additionally, the literature on digital health interventions and digital learning suggests that interactivity, the extent to which the participant engages either with the technology (e.g. drag and drop exercises) or with another actor (e.g. therapist), Reference Khan29,Reference Khan30 and synchronicity, whether the interaction occurs in real time with the simultaneous presence of both parties (i.e. synchronous) or at separate times (i.e. asynchronous), Reference Yang, Yu and Chen31,Reference Shahabadi and Uplane32 have also been identified as factors affecting outcomes. Given the importance of psychoeducation and behavioural changes as components of many digital interventions, interactivity and synchronicity could be important intervention characteristics to assess in the delivery of remote interventions.
Many systematic reviews and meta-analyses have investigated the efficacy of digital and remote interventions for PTSD, Reference Kuhn and Owen33,Reference Tng, Koh, Soh, Majeed and Hartanto34 some focusing on specific characteristics and content, including exposure-based digital interventions, Reference Yoshikawa, Narita and Kim35 platforms like PTSD Coach Reference Bröcker, Suliman, Olff and Seedat36 and specific population groups like youth. Reference Schulte, Harrer, Sachser, Weiss and Zarski37 Most existing remote interventions are designed for PTSD, however, and little is known about remote interventions for TSRDs such as AjD and ASD. A recent systematic review and meta-analysis of remote and digital interventions for AjD Reference Fernández-Buendía, Miguel, Dumarkaite, Kazlauskas, Cuijpers and Quero38 observed that the literature is still too scarce and heterogeneous to draw conclusions on their acceptability and usability.
Research objectives
The diverse and evolving state of current literature across diagnoses and remote technologies calls for a comprehensive account of research conducted to date on diagnoses beyond PTSD, such as AjD and ASD. This systematic review aimed to identify remote interventions for TSRDs, defined as psychological interventions requiring the use of a technological device to provide support for individuals affected by TSRDs, where patients and providers were located in different environments. The main characteristics of remote interventions – modality, interactivity, synchronicity and therapeutic approach – served as the foundation for assessments of feasibility (drop-out rates, recruitment rates) and acceptability (adherence to treatment, satisfaction).
Method
Study design
A mixed-method systematic review was conducted, Reference Pearson, White, Bath-Hextall, Salmond, Apostolo and Kirkpatrick39 as the synthesis of both quantitative and qualitative research would provide a more nuanced and in-depth understanding of the relevant literature. Reference Grant and Booth40 This methodology also allowed for a critical appraisal of the literature. The mixed methods systematic review protocol (PROSPERO registration number, CRD42022300775) was developed and executed according to the PRISMA 2020 guidelines Reference Page, McKenzie, Bossuyt, Boutron, Hoffmann and Mulrow41 (see Supplementary Material for the PRISMA checklist, available at https://doi.org/10.1192/bjo.2025.10832).
Search strategy
The following electronic databases were searched: PubMed, MEDLINE, CINAHL, Embase and PsycInfo, for primary studies published between January 2011 and December 2023. The search was updated in May 2024 to include more recent studies. A total of 13 search strings were developed, including keywords representing exposure to traumatic events and stressors, TSRDs, remote technologies and treatment (see Supplementary Material for full search strategy). Only original, published, peer-reviewed studies were included. All citations were downloaded to the Endnote citation management program, and duplicates were removed.
Study identification and selection
The study identification criteria were: (a) articles that reported feasibility and acceptability outcomes for TSRD interventions delivered remotely to adults (≥18 years old); (b) patient samples with TSRD diagnoses (PTSD, ASD or AjD), or with clinically significant trauma- or stressor-related symptoms at pre-treatment; (c) quantitative studies reporting pre- and post-treatment data for an intervention group, or post-treatment data for both an intervention and comparison group (e.g. other intervention, face-to-face intervention, waitlist, treatment as usual, etc.); (d) qualitative studies employing data collection methods (in-depth interviews, focus groups) to enhance understanding of participant experiences with remote psychological interventions for PTSD, ASD or AjD; (e) studies of remote interventions (self-administered, clinician-administered or a combination) using any technical platform (computer/internet/videoconference, mobile device or applications, telephone/text messaging); and (f) language of publication was French or English. Studies where interventions employed a technical platform not delivered remotely (e.g. in-office virtual reality interventions) were excluded, as were reviews and studies not published in peer-reviewed academic journals (e.g. case reports, opinion papers, theses and dissertations, conference proceedings).
Screening process
A preliminary selection of articles was performed using Rayyan (2014, Qatar Computing Research Institute, Cambridge, MA; see https://www.rayyan.ai/), a free web-based platform that facilitates systematic review screening by allowing researchers to independently screen titles and abstracts, apply inclusion/exclusion criteria and resolve conflicts through a blinding and labelling system. Reference Ouzzani, Hammady, Fedorowicz and Elmagarmid42 The study selection process involved two trained raters (M.R.-B. and J.F.) and was conducted in two phases: (a) a title-abstract screening and (b) a full-text review. The raters independently screened titles and abstracts and excluded studies based on the following criteria: (a) participants younger than 18 years old; (b) intervention not focused on PTSD, ASD or AjD; (c) treatment administered in-person or off-line; and (d) grey literature. The same raters independently conducted the full-text review, using the inclusion and exclusion criteria described above. At each phase of the screening process, the two raters resolved disagreements by consensus, or by the senior author (M.F.) in nine cases involving full-text screening where consensus could not be reached because of ambiguities in the diagnostic criteria used.
Quality assessment
During the quality assessment phase, each study was assessed independently by two of the three raters (M.R.-B., J.F. and C.P.), using standardised tools. Quality assessments tools used for the quantitative papers were from the National Heart, Lung and Blood Institute, 43 whereas the qualitative papers were assessed using the Critical Appraisal Skills Program Checklist. 44 Mixed-method studies were assessed using both tools. The tools were selected for their methodologically rigorous development and detailed items used in the assessment of risk bias. The critical appraisal rating rules can be found in the Supplementary Material. The independent ratings were then discussed among the raters to reach consensus, and in cases where disagreement remained, the senior author (M.F.) was consulted to resolve conflicts. This process ensured that each study underwent rigorous and unbiased quality assessment.
Data extraction and synthesis
Three trained raters (M.R.-B., J.F. and E.G.), supervised by the senior author (M.F.), independently and dually extracted data for each study retained for review, using a data extraction table comprised of (a) publication information: author name(s), year, title; (b) study characteristics: country of recruitment, study objective(s), hypotheses/research questions, study design, comparison group, methods (data collection/time points, measures, analysis), reported study limitations; (c) participant characteristics: sample size, age, trauma type, diagnosis; (d) remote intervention characteristics: therapeutic model/name of remote intervention, technology used, method of administration, intervention content, intervention length, frequency of therapist contact, timing of therapist contact, timing of intervention; and (e) outcomes (quantitative and qualitative): symptom outcomes, drop-out rates, recruitment rates, adherence to treatment, adverse events, satisfaction measures, perceived risks and benefits. During the extraction phase, each study was reviewed by at least two (or the three) independent raters. Differences were first discussed between the two raters to reach consensus. If consensus could not be reached, the senior author (M.F.) was consulted to resolve disagreements. This process ensured accuracy and consistency in data extraction. For the qualitative studies, acceptability outcomes included key themes and concepts that captured patient perceptions of how the interventions mitigated trauma- and stressor-related symptoms. Data extraction began on 25 July 2023, and data extraction for the updated search (May 2024) began on 6 May 2024. The first author (M.R.-B.) and senior author (M.F.) synthesised the results by using the narrative approach described by Popay et al. Reference Popay, Roberts, Sowden, Petticrew, Arai and Rodgers45 All co-authors (J.F., M.L., E.G., A.B.) revised and approved the final synthesis. A meta-analysis was not indicated because of the high degree of heterogeneity across studies, e.g. in terms of psychiatric diagnoses, intervention modalities and outcome measures, as this would compromise comparability of the results. Reference Higgins, Thomas, Chandler, Cumpston, Li and Page46,47
Results
Study characteristics
The final search led to the retrieval of 19 332 studies, of which 10 160 were screened, yielding 241 studies that were assessed for inclusion. Of these, 167 were excluded. In all, 74 studies were selected for review, as shown in Fig. 1. Most were conducted in the USA (k = 30) and Europe (k = 26), whereas others originated from Canada (k = 3), Australia (k = 4), Asia (k = 5) and Africa (k = 4). One was a multi-country study (Egypt, Saudi Arabia, Algeria, Syria, Morocco, Palestine; k = 1) and one did not report a country. Reference Yoshikawa, Narita and Kim35 Most studies used quantitative methods (k = 59), followed by qualitative (k = 6) and mixed methods (k = 9). A total of 27 interventions were investigated, with studies targeting PTSD (k = 66), AjD (k = 5) and post-traumatic stress symptoms (k = 3). No studies specifically investigated ASD. Studies reported four main treatment delivery modalities: online modules (k = 47), mobile applications (k = 17), video-based teletherapy (k = 9) and message-based teletherapy (k = 1). Figure 2 presents a detailed breakdown of synchronicity, according to modality, whereas Supplementary Table 1 and Table 1 present the study characteristics of quantitative and qualitative studies, respectively. The results within each modality are reported below.
Fig. 1 Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) flow chart of included studies.
Fig. 2 Synchronicity of the included studies for modality. Async, asynchronous; Mixt, mixed synchronicity; Sync, synchronous.
Online modules
Given the various levels of interactivity and synchronicity characteristic of the 47 studies using online modules, they were further divided into four subcategories: therapist-directed modules, self-directed non-interactive modules, self-directed interactive modules and writing therapy.
Description. Four studies, three quantitative and one mixed method, investigated clinician-directed online modules, led by a nurse (k = 1, DESTRESS-PC) Reference Engel, Litz, Magruder, Harper, Gore and Stein50 or therapist (k = 3). These interventions were offered asynchronously (k = 2; HOPE, Reference Bragesjö, Ivanov, Andersson and Rück48 Peaceful Mind iCBT Reference Shafierizi, Faramarzi, Nasiri-Amiri, Chehrazi, Basirat and Kheirkhah51 ) or module delivery was asynchronous, and clinician-supported synchronously (k = 2; webSTAIR, Reference Bauer, Amspoker, Fletcher, Jackson, Jacobs and Hogan49 DESTRESS-PC Reference Engel, Litz, Magruder, Harper, Gore and Stein50 ). Three interventions were offered for PTSD and one for AjD (Peaceful Mind iCBT). Reference Shafierizi, Faramarzi, Nasiri-Amiri, Chehrazi, Basirat and Kheirkhah51
Two studies Reference Ivarsson, Blom, Hesser, Carlbring, Enderby and Nordberg52,Reference Spence, Titov, Johnston, Jones, Dear and Solley53 investigated self-directed, non-interactive online modules, with treatments offered asynchronously and including text-based reading material. Both studies were randomised controlled trials (RCTs), with a monitored waitlist and alternative version of the course as comparison groups. Both interventions targeted PTSD, using CBT. Both treatments were delivered over 8 weeks.
Another 25 quantitative, three mixed-method and three qualitative interventions involved self-directed, interactive online modules, offered asynchronously. They included text-based readings with interactive exercises (e.g. meditations and relaxation, ‘drag and drop’ exercises). Some modules also included interactivity components with a clinician (k = 16) or a peer community (k = 2). Most studies were RCTs (k = 16) comparing online modules to treatment as usual (TAU) (k = 2), alternative modalities (k = 5), waitlists (k = 7), non-clinical populations (k = 1) and a clinician-guided version (k = 1). Others were pre-/post-observational studies (k = 13), whereas four of the studies used mixed methods: webSTAIR, Reference Fletcher, Amspoker, Wassef, Hogan, Helm and Jackson62 Web-PE, Reference McLean, Miller, Dondanville, Rauch, Yarvis and Wright73 Spring Reference Bisson, Ariti, Cullen, Kitchiner, Lewis and Roberts56,Reference Simon, Lewis, Smallman, Brookes-Howell, Roberts and Kitchiner79 (Supplementary Table 1). Most studies using self-directed, interactive modalities targeted interventions for PTSD, using CBT (k = 18), eye movement desensitisation and reprocessing (EMDR) (k = 1), mindfulness (k = 2) or acceptance and commitment therapy (ACT) (k = 1), whereas four studies investigated interventions for AjD using CBT (k = 2) or CBT and mindfulness (k = 2), and three studies investigated interventions for unspecified TSRD using CBT. Treatment length varied from 3 to 12 weeks, and three interventions were completed at the participant’s pace (webSTAIR, Reference Fletcher, Amspoker, Wassef, Hogan, Helm and Jackson62 Spring, Reference Simon, Lewis, Smallman, Brookes-Howell, Roberts and Kitchiner79 BADI Reference Eimontas, Gegieckaite, Dovydaitiene, Mazulyte, Rimsaite and Skruibis59 ).
Nine quantitative studies investigated online writing therapy, all developed asynchronously and offered for PTSD using CBT. All interventions included asynchronous therapist involvement through messages or feedback on assignments. Predetermined treatment length varied between 5 (k = 5) and 6 weeks (k = 3). The integrative testimonial therapy (ITT) Reference Feder, Kowalchyk, Brinkman, Cahn, Aaronson and Böttche85 had no predetermined length, but took 9 weeks on average to complete.
Feasibility. The four studies with clinician-directed online interventions reported recruitment rates (Fig. 3(a)) between 16.29% (DESTRESS-PC) Reference Engel, Litz, Magruder, Harper, Gore and Stein50 and 33.0% (Peaceful Mind). Reference Shafierizi, Faramarzi, Nasiri-Amiri, Chehrazi, Basirat and Kheirkhah51 Drop-out rates (Fig. 3(b)) ranged between 9% for Peaceful Mind and 43.8% for webSTAIR. Reference Engel, Litz, Magruder, Harper, Gore and Stein50 Study completion rates (Fig. 3(c)), ranged from 32% for HOPE Reference Bragesjö, Ivanov, Andersson and Rück48 to 88.20% for Peaceful Mind.
Fig. 3 Indicators of feasibility across all modalities. (a) Rate of recruitment. (b) Drop-out rates. (c) Completion rates. iCBT, internet cognitive–behavioural therapy; PTSD, post-traumatic stress disorder; CIPE, condensed internet-delivered prolonged exposure; BADI, brief adjustment disorder intervention; ACT, acceptance and commitment therapy; ICT-TIPs, implantable cardioverter defibrillator trauma intervention protocol; iCBT-MY, internet cognitive–behavioural therapy, mindfulness meditation and yoga; DESTRESS-WV, delivery of self training and education for stressful situations – women veterans version; Web-PE, web-prolonged exposure; TF-iCBT, trauma-focused internet cognitive–behavioural therapy; TAO, Spanish acronym for ‘adjustment disorders online’; EMDR, eye movement desensitisation and reprocessing; DESTRESS-PC, delivery of self training and education for stressful situations – primary care version; ITT, integrative testimonial therapy; REPAIR, reducing post-traumatic stress after severe sepsis in patients and their spouse; PTSD Coach-CS, PTSD coach counsellor-supported; CPT, cognitive processing therapy; STAIR, skills training in affective and interpersonal regulation; VIOPP, virtual intensive outpatient program for PTSD; HTMH, cognitive processing, home telemental health cognitive processing.
Recruitment rates for both studies on self-directed, non-interactive modules were 42.76% for iCBT Reference Ivarsson, Blom, Hesser, Carlbring, Enderby and Nordberg52 and 53.65% for PTSD Course, Reference Spence, Titov, Johnston, Jones, Dear and Solley53 whereas drop-out rates were 19 and 27%, respectively. Although module completion rates were variable, 38.71% of iCBT participants and 76% of PTSD Course participants (73% exposure group versus 79% non-exposure group) completed all modules (Fig. 3(c)).
Recruitment rates were reported for 22/29 studies on self-directed, interactive modules, ranging between 2.17% for Vets Prevail Reference Hobfoll, Blais, Stevens, Walt and Gengler65 and 79.82% for Terapia Emocional. Reference Quero, Rachyla, Molés, Mor, Tur and Cuijpers77 Drop-out rates reported by all studies (k = 29) ranged between 0% for iCT-PTSD Reference Wild, Warnock-Parkes, Grey, Stott, Wiedemann and Canvin82 and CIPE Reference Bragesjö, Arnberg, Särnholm, Olofsdotter Lauri and Andersson57 and 86.50% for BADI. Reference Eimontas, Rimsaite, Gegieckaite, Zelviene and Kazlauskas60 Module completion rates (Fig. 3(c)) were reported by 19 of the studies, ranging from 4.10% (BADI Reference Eimontas, Rimsaite, Gegieckaite, Zelviene and Kazlauskas60 ) to 94.00% (CBT-MY Reference Kirk, Taha, Dang, McCague, Hatzinakos and Katz66 ).
Seven of the nine studies on online writing therapy reported recruitment rates ranging between 3.71% for TF-Short Reference Böttche, Wagner, Vöhringer, Heinrich, Stein and Selmo84 and 43.86% for REPAIR. Reference Gawlytta, Kesselmeier, Scherag, Niemeyer, Böttche and Knaevelsrud86 All studies reported dropout rates, which ranged between 9% for ITT Reference Böttche, Kuwert, Pietrzak and Knaevelsrud83 and 62.50% for TF-Short. Reference Böttche, Wagner, Vöhringer, Heinrich, Stein and Selmo84 Finally, two studies reported completion rates on all writing assignments, 74% for Interapy Reference Knaevelsrud, Brand, Lange, Ruwaard and Wagner88 and 81% for ITT. Reference Feder, Kowalchyk, Brinkman, Cahn, Aaronson and Böttche85
Acceptability. The acceptability of self-directed, non-interactive interventions was only assessed for PTSD Course. Reference Spence, Titov, Johnston, Jones, Dear and Solley53 Most participants reported being mostly or very satisfied (82%) with the interventions (with/without exposure), whereas 94–98% of participants in the non-exposure and exposure interventions respectively reported that they would confidently recommend the intervention.
Eighteen of the 29 studies on self-directed, interactive interventions reported acceptability from a user perspective, most of whom reported high levels of satisfaction for most of their participants (k = 14), whereas a few studies reported the interventions as at least moderately useful (k = 5).
Participants using the clinician-directed modules Peaceful Mind iCBT for AjD Reference Shafierizi, Faramarzi, Nasiri-Amiri, Chehrazi, Basirat and Kheirkhah51 and webSTAIR Reference Bragesjö, Ivanov, Andersson and Rück48 reported that the presence of a clinician, and good rapport between participants and clinicians were important components of the interventions, increasing their acceptability. Studies investigating webSTAIR Reference Bauer, Amspoker, Fletcher, Jackson, Jacobs and Hogan49 and HOPE Reference Bragesjö, Ivanov, Andersson and Rück48 reported medium to high satisfaction scores from participants.
Finally, three of the nine studies on online writing therapy investigated participants’ satisfaction, reporting that participants were satisfied with the intervention (k = 1, ITT Reference Feder, Kowalchyk, Brinkman, Cahn, Aaronson and Böttche85 ), or with the therapist and the therapeutic process (k = 2, ITT Reference Knaevelsrud, Böttche, Pietrzak, Freyberger, Renneberg and Kuwert87,Reference Knaevelsrud, Böttche, Pietrzak, Freyberger and Kuwert89 ).
Qualitative findings. Three qualitative and four mixed-method studies (Table 1) investigated self-directed and clinician-guided interactive online modules: CIPE, Reference Bragesjö, Arnberg, Jelbring, Nolkrantz, Särnholm and Olofsdotter Lauri115 Coming Home and Moving Forward, Reference Possemato, Acosta, Fuentes, Lantinga, Marsch and Maisto117 PTSD Coach Online, Reference Ellis, Hosny and Miller-Graff116 Spring, Reference Simon, Lewis, Smallman, Brookes-Howell, Roberts and Kitchiner79 Web-PE Reference McLean, Miller, Dondanville, Rauch, Yarvis and Wright73 and webSTAIR. Reference Fletcher, Amspoker, Wassef, Hogan, Helm and Jackson62,Reference Bragesjö, Ivanov, Andersson and Rück48
Table 1 Characteristics of included studies using qualitative methodologies
PTSD, post-traumatic stress disorder; STAIR, skills training in affective and interpersonal regulation; PTSS, post-traumatic stress symptoms; CIPE, condensed internet-delivered prolonged exposure; CBT, cognitive-behavioural therapy; Web-PE, web-prolonged exposure; CBT-TF, trauma-focused cognitive–behavioural therapy; PTSD Coach-CS, PTSD coach counsellor-supported; PE Coach, prolonged exposure coach; SUD, substance use disorder; EMDR, eye movement desensitisation and reprocessing.
a. Study was a mixed-methods design.
Qualitative inquiries of study participants resulted in three overarching themes: perceived benefits, motivations and barriers to engagement, and suggestions for improvement. The perceived benefits of interventions included various approaches and tools, and multiple skills learned from the modules (PTSD Coach Online; Reference Ellis, Hosny and Miller-Graff116 Spring; Reference Simon, Lewis, Smallman, Brookes-Howell, Roberts and Kitchiner79 CIPE; Reference Bragesjö, Arnberg, Jelbring, Nolkrantz, Särnholm and Olofsdotter Lauri115 webStair Reference Bragesjö, Ivanov, Andersson and Rück48,Reference Fletcher, Amspoker, Wassef, Hogan, Helm and Jackson62 ), although some participants found the tools or format and delivery of the exercises unhelpful (PTSD Coach Online; Reference Ellis, Hosny and Miller-Graff116 CIPE Reference Bragesjö, Arnberg, Jelbring, Nolkrantz, Särnholm and Olofsdotter Lauri115 ). The online modules were good stepping stones to treatment (Coming Home and Moving Forward; Reference Possemato, Acosta, Fuentes, Lantinga, Marsch and Maisto117 PTSD Coach Online Reference Ellis, Hosny and Miller-Graff116 ). Yet previous therapy recipients already familiar with module content found it insufficient (PTSD Coach Online Reference Ellis, Hosny and Miller-Graff116 ). Perceived benefits of the online platform included easy and unlimited access (Web-PE; Reference McLean, Miller, Dondanville, Rauch, Yarvis and Wright73 PTSD Coach Online; Reference Ellis, Hosny and Miller-Graff116 CIPE; Reference Bragesjö, Arnberg, Jelbring, Nolkrantz, Särnholm and Olofsdotter Lauri115 webStair Reference Bragesjö, Ivanov, Andersson and Rück48 ) as well as self-paced module completion (Coming Home and Moving Forward Reference Possemato, Acosta, Fuentes, Lantinga, Marsch and Maisto117 ). The novelty of online treatment was also underlined in PTSD Coach Online, adapted to Arabic, revealing the need for linguistic and cultural adaptations. Reference Ellis, Hosny and Miller-Graff116 The Possemato evaluation Reference Possemato, Acosta, Fuentes, Lantinga, Marsch and Maisto117 reported that the platform in Coming Home and Moving Forward helped reduce PTSD symptoms, although core dimensions like substance use and anger management were missing. Participants who received CIPE identified imaginal exposure as very demanding, but also the most effective component. Reference Bragesjö, Arnberg, Jelbring, Nolkrantz, Särnholm and Olofsdotter Lauri115 Finally, regarding Web-PE and webStair, contact and support from the therapist were highly valued enhancements. Reference McLean, Miller, Dondanville, Rauch, Yarvis and Wright73,Reference Bragesjö, Ivanov, Andersson and Rück48,Reference Fletcher, Amspoker, Wassef, Hogan, Helm and Jackson62
Engagement in online treatment was discussed in terms of motivations and barriers. Regarding motivation to engage in treatment, the PTSD Coach Online platform provided constant availability and accessibility, while eliminating the main barriers to traditional face-to-face therapy, such as time and money constraints, fear of disclosure and stigma. Reference Ellis, Hosny and Miller-Graff116 The clinician component in Spring and CIPE also promoted engagement. Reference Simon, Lewis, Smallman, Brookes-Howell, Roberts and Kitchiner79,Reference Bragesjö, Arnberg, Jelbring, Nolkrantz, Särnholm and Olofsdotter Lauri115 Among barriers to engagement, PTSD Coach Online users Reference Ellis, Hosny and Miller-Graff116 found the simplistic material and inability to apply content to realistic, complex life situations problematic, whereas those using Web-PE and Spring found the exercises more challenging. Reference McLean, Miller, Dondanville, Rauch, Yarvis and Wright73,Reference Simon, Lewis, Smallman, Brookes-Howell, Roberts and Kitchiner79 Other barriers to engagement also included lack of time and motivation in Web-PE and CIPE, Reference McLean, Miller, Dondanville, Rauch, Yarvis and Wright73,Reference Bragesjö, Arnberg, Jelbring, Nolkrantz, Särnholm and Olofsdotter Lauri115 and lack of human contact and therapeutic relationships in PTSD Coach Online and CIPE. Reference Bragesjö, Arnberg, Jelbring, Nolkrantz, Särnholm and Olofsdotter Lauri115,Reference Ellis, Hosny and Miller-Graff116
Another set of barriers underlined technical difficulties (Web-PE; Reference McLean, Miller, Dondanville, Rauch, Yarvis and Wright73 webStair Reference Bragesjö, Ivanov, Andersson and Rück48 ) like interfaces that were not user-friendly and could not be personalised (PTSD Coach Online Reference Ellis, Hosny and Miller-Graff116 ). Also, users felt uncertain about the confidentiality of responses given on the interactive exercises in Coming Home and Moving Forward. Reference Possemato, Acosta, Fuentes, Lantinga, Marsch and Maisto117
Finally, participants provided suggestions for delivering materials, such as including video content with modules and adding a support component with a live chat in (PTSD Coach Online) Reference Ellis, Hosny and Miller-Graff116 and (Coming Home and Moving Forward), Reference Possemato, Acosta, Fuentes, Lantinga, Marsch and Maisto117 adopting an incentive-based approach to enhance use of the platform, and adding reminders and notifications (Coming Home and Moving Forward). Reference Possemato, Acosta, Fuentes, Lantinga, Marsch and Maisto117
Mobile applications
Description. Twelve quantitative and two mixed-method studies investigated the use of mobile applications, primarily PTSD Coach, with k = 8 adaptations. Reference Bröcker, Olff, Suliman, Kidd, Greyvenstein and Seedat92,Reference Hensler, Sveen, Cernvall and Arnberg93,Reference Kuhn, Greene, Hoffman, Nguyen, Wald and Schmidt94,Reference Kuhn, Kanuri, Hoffman, Garvert, Ruzek and Taylor95,Reference Miner, Kuhn, Hoffman, Owen, Ruzek and Taylor97,Reference Possemato, Kuhn, Johnson, Hoffman, Owen and Kanuri99,Reference Possemato, Johnson, Barrie, Ghaus, Noronha and Wade100,Reference Smith, Kuhn, O’Donnell, Koontz, Nelson and Molloy104 All application-based interventions were asynchronous and self-administered, whereas recent studies reported an additional interactive clinician component including both synchronous and asynchronous formats: PTSD Coach with clinician support Reference Bröcker, Olff, Suliman, Kidd, Greyvenstein and Seedat92,Reference Possemato, Kuhn, Johnson, Hoffman, Owen and Kanuri99,Reference Possemato, Johnson, Barrie, Ghaus, Noronha and Wade100 and PE Coach, Reference Reger, Stevens, Reisinger, Norr, Buck and Zoellner101 or community support: Seeking Safety. Reference Najavits, Cha, Demce, Gupta, Haney and Logounov98 They all aimed to treat PTSD using a CBT therapeutic approach, but interventions targeting PTSD also included a mindfulness and acceptance intervention that used ACT Reference Reyes, Song, Bhatta and Kearney102 and another ACT intervention. Reference Zhao, Zhao, Levin, Lai, Shi and Hu105 Treatment length varied between 3 and 21 weeks, although PE Coach Reference Reger, Stevens, Reisinger, Norr, Buck and Zoellner101 did not include this information.
Feasibility. Recruitment rates were given for ten out of 14 studies, ranging between 2.16% for ACT Reference Zhao, Zhao, Levin, Lai, Shi and Hu105 and 78.24% for Sanadak ( Reference Röhr, Jung, Pabst, Grochtdreis, Dams and Nagl103 ; Fig. 3(a)). Drop-out rates for 11 out of 12 studies ranged between 0% for Seeking Safety Reference Najavits, Cha, Demce, Gupta, Haney and Logounov98 and 30% for PE Coach Reference Reger, Stevens, Reisinger, Norr, Buck and Zoellner101 (Fig. 3(b)). Completion rates (Fig. 3(c)), reported as average number of logins or use per week, varied between 1.29 (PTSD Coach) Reference Kuhn, Kanuri, Hoffman, Garvert, Ruzek and Taylor95 and 2.8 (Cancer Distress Coach). Reference Smith, Kuhn, O’Donnell, Koontz, Nelson and Molloy104 For PTSD Coach, the average use of individual sections varied between 5.1 and 11.7 times per week, Reference Possemato, Kuhn, Johnson, Hoffman, Owen and Kanuri99 whereas users spent an average of 102–122 min per week on Renew. Reference McLean, Davis, Miller, Ruzek and Neri96
Acceptability. Acceptability outcomes were reported for six out of 14 studies on mobile apps, including perceived usefulness and satisfaction, which were rated as moderate or better by participants across all studies; many also reported high satisfaction and helpfulness for PTSD Coach-CS, Reference Bröcker, Olff, Suliman, Kidd, Greyvenstein and Seedat92,Reference Possemato, Kuhn, Johnson, Hoffman, Owen and Kanuri99,Reference Possemato, Johnson, Barrie, Ghaus, Noronha and Wade100 PTSD Coach, Reference Hensler, Sveen, Cernvall and Arnberg93 Cancer Distress Coach Reference Smith, Kuhn, O’Donnell, Koontz, Nelson and Molloy104 and PE Coach. Reference Reger, Stevens, Reisinger, Norr, Buck and Zoellner101 Only users of Sanadak and PTSD Coach reported adverse effects from the apps, namely increased anxiety from Sanadak Reference Röhr, Jung, Pabst, Grochtdreis, Dams and Nagl103 and negative effects of PTSD Coach, such as increased distress and unfulfilled expectations. Reference Hensler, Sveen, Cernvall and Arnberg93
Qualitative findings. Three qualitative and two mixed-method studies investigated mobile applications using qualitative methods. Three of them, PTSD Help, Reference Riisager, Christensen, Scharff, Arendt, Ismail and Lau120 PTSD Coach with Clinician Support Reference Bröcker, Scheffler, Suliman, Olff and Seedat118 and a mindfulness and acceptance intervention, Reference Reyes, Serafica and Sojobi119 used qualitative methods whereas PE Coach Reference Reger, Stevens, Reisinger, Norr, Buck and Zoellner101 and PTSD Coach Reference Kuhn, Greene, Hoffman, Nguyen, Wald and Schmidt94 used a mixed-method approach.
The qualitative analysis produced three themes: mobile application use in mindfulness and acceptance, Reference Reyes, Serafica and Sojobi119 PTSD Coach, Reference Kuhn, Greene, Hoffman, Nguyen, Wald and Schmidt94 PTSD Help Reference Riisager, Christensen, Scharff, Arendt, Ismail and Lau120 and PE Coach Reference Reger, Stevens, Reisinger, Norr, Buck and Zoellner101 ; perceived benefits in mindfulness and acceptance Reference Reyes, Serafica and Sojobi119 and PTSD Coach; Reference Kuhn, Greene, Hoffman, Nguyen, Wald and Schmidt94,Reference Bröcker, Scheffler, Suliman, Olff and Seedat118 and constructive criticism in PTSD Coach, Reference Kuhn, Greene, Hoffman, Nguyen, Wald and Schmidt94 PTSD Help Reference Riisager, Christensen, Scharff, Arendt, Ismail and Lau120 and PE Coach. Reference Reger, Stevens, Reisinger, Norr, Buck and Zoellner101
The theme regarding mobile application use included habit formation and generating momentum for use in PTSD Coach Reference Kuhn, Greene, Hoffman, Nguyen, Wald and Schmidt94 and mindfulness and acceptance. Reference Reyes, Serafica and Sojobi119 Motivations included using apps as a distraction in PTSD Help, or problem management in (PTSD Coach and PTSD Help) related to PTSD. Reference Kuhn, Greene, Hoffman, Nguyen, Wald and Schmidt94,Reference Riisager, Christensen, Scharff, Arendt, Ismail and Lau120 Attitudes toward the app, e.g. positivity or open-mindedness regarding its potential usefulness, were another motivator in mindfulness and acceptance and PTSD Help. Reference Reyes, Serafica and Sojobi119,Reference Riisager, Christensen, Scharff, Arendt, Ismail and Lau120 Participants who used PE Coach Reference Reger, Stevens, Reisinger, Norr, Buck and Zoellner101 reported that the homework function improved their accountability. However, motivation to use PTSD Help was adversely affected by technological dysfunctions, causing some users to drop out. Reference Riisager, Christensen, Scharff, Arendt, Ismail and Lau120
Perceived benefits of PTSD Coach and PTSD Help were highlighted in relation to reducing, de-escalating and managing symptoms and distress Reference Kuhn, Greene, Hoffman, Nguyen, Wald and Schmidt94,Reference Bröcker, Scheffler, Suliman, Olff and Seedat118,Reference Riisager, Christensen, Scharff, Arendt, Ismail and Lau120 ; in obtaining psychoeducational material on PTSD for oneself or others in PTSD Coach, Reference Kuhn, Greene, Hoffman, Nguyen, Wald and Schmidt94 PTSD Help Reference Bröcker, Scheffler, Suliman, Olff and Seedat118,Reference Riisager, Christensen, Scharff, Arendt, Ismail and Lau120 and mindfulness and acceptance; Reference Reyes, Serafica and Sojobi119 and in providing useful materials for daily use. Reference Bröcker, Scheffler, Suliman, Olff and Seedat118,Reference Reyes, Serafica and Sojobi119 However, some PTSD Help users identified increasing symptom awareness as a negative experience. Reference Riisager, Christensen, Scharff, Arendt, Ismail and Lau120 Others viewed the clinician component in clinician-supported applications like PTSD Coach with clinician support Reference Bröcker, Scheffler, Suliman, Olff and Seedat118 as a facilitator for self-acceptance of PTSD, whereas others found the clinician component less helpful, stating that clinicians were insufficiently attuned to their feelings or did not involve the family. Reference Bröcker, Scheffler, Suliman, Olff and Seedat118
Participants offered constructive criticism of all mobile applications, sharing positive perceptions of PTSD Help, PTSD Coach and PE Coach as accessible, easy to use and convenient, Reference Kuhn, Greene, Hoffman, Nguyen, Wald and Schmidt94,Reference Reger, Stevens, Reisinger, Norr, Buck and Zoellner101,Reference Riisager, Christensen, Scharff, Arendt, Ismail and Lau120 although the PTSD Help interface was not considered intuitive and provoked confusion. Reference Riisager, Christensen, Scharff, Arendt, Ismail and Lau120 Participants also highlighted the importance of notifications and reminders as enhancements for certain PTSD Help features and appreciated the opportunity to personalise the app as well as certain exercises in PTSD Help and PTSD Coach. Reference Kuhn, Greene, Hoffman, Nguyen, Wald and Schmidt94,Reference Riisager, Christensen, Scharff, Arendt, Ismail and Lau120 PE Coach users suggested that the app and progress data should be transferable across devices, to allow for concurrent use with other intervention components. Reference Reger, Stevens, Reisinger, Norr, Buck and Zoellner101 However, some users of PTSD Coach with clinician support Reference Bröcker, Scheffler, Suliman, Olff and Seedat118 preferred clinician support, claiming that mobile applications provided insufficient response to their treatment needs.
Video conferencing-delivered interventions
Description. Seven quantitative and two mixed-method studies reported only the qualitative findings from psychotherapy sessions delivered through video conferencing, Reference Strelchuk, Turner, Smith, Bisson, Wiles and Zammit112,Reference Ferkul, Agabani, Minami, Bormann, Le Foll and Lobo121 both clinician-administered and synchronous. The sessions were conducted from patients’ homes or, in the case of CBT for PTSD, in a clinic. Reference Marchand, Beaulieu-Prévost, Guay, Bouchard, Drouin and Germain109
Only PTSD was investigated using video conferencing. The therapeutic approaches investigated included CBT (k = 5), CBT and ACT (k = 1), and EMDR (k = 2). Treatment duration ranged between 2.5 weeks (EMDR R-TEP Reference Sağaltıcı, Çetinkaya, Şahin, Gülen and Karaman111 ) and 25 weeks (iCBT Reference Marchand, Beaulieu-Prévost, Guay, Bouchard, Drouin and Germain109 ). The intervention offering iEMDR did not report intervention length. Reference Strelchuk, Turner, Smith, Bisson, Wiles and Zammit112
Feasibility. Recruitment rates from video conferencing studies ranged between 28% in iCBT Conjoint Therapy Reference Possemato, Johnson, Barrie, Ghaus, Noronha and Wade100 and 52.79% in STAIR (see Fig. 3a in Cloitre et al Reference Cloitre, Morabito, Macia, Speicher, Froelich and Webster106 ). Alternatively, drop-out rates reported for all studies ranged between 0% for both EMDR and prolonged exposure Reference Miner, Kuhn, Hoffman, Owen, Ruzek and Taylor97 and for iCBT Conjoint Therapy Reference Hendrikx, Phee and Murphy108 and 38.3% for HTMH Cognitive Processing (see Fig. 7 in Reference Whealin, King, Shore and Spira113 ). Finally, completion rates ranged between 81% in CPT Reference Murphy and Turgoose110 and 100% (iCBT Conjoint Therapy; Reference Hendrikx, Phee and Murphy108 see Fig. 3(c)).
Acceptability. Five of the studies reported acceptability results, of which four investigated acceptability from a user perspective, and the remaining two from a clinician perspective. Users of the video conferencing platforms reported high satisfaction with the STAIR intervention, Reference Cloitre, Morabito, Macia, Speicher, Froelich and Webster106 and being comfortable interacting with the clinician and the technology in the HTMH cognitive processing intervention. Reference Whealin, King, Shore and Spira113 CPT users also reported high levels of satisfaction with their therapeutic relationships. Reference Murphy and Turgoose110 Clinicians reported that their patients felt comfortable and were able to engage throughout cognitive–behaviour conjoint therapy, Reference Hendrikx, Phee and Murphy108 whereas therapists administering iEMDR highlighted the flexibility and accessibility of video conferencing, and reported having no difficulties developing good therapeutic relationships. Reference Strelchuk, Turner, Smith, Bisson, Wiles and Zammit112
Qualitative findings. Two studies, both from mixed-method studies, reported qualitative findings. One study investigated the provision of iEMDR from both the therapist and participant perspective, Reference Strelchuk, Turner, Smith, Bisson, Wiles and Zammit112 whereas the virtual Mantram program MRP was investigated from participant perspectives. Reference Ferkul, Agabani, Minami, Bormann, Le Foll and Lobo121 Qualitative findings produced three themes, including experience with intervention content and the delivery format, and suggestions for improvement.
Regarding the content of interventions, therapists who delivered iEMDR reported that some phases of the intervention had to be adapted, as they were not sufficiently reliable for online performance, given technological limitations like eye movement, whereas distress management techniques were efficient in that no safety issues arose. Reference Strelchuk, Turner, Smith, Bisson, Wiles and Zammit112 Regarding MRP, the psychoeducative and skill development components, along with mental grounding, were all perceived as beneficial and practical in allowing participants to manage their symptoms and triggering situations. Reference Ferkul, Agabani, Minami, Bormann, Le Foll and Lobo121
Therapists looking for scheduling flexibility appreciated online delivery of iEMDR. Reference Strelchuk, Turner, Smith, Bisson, Wiles and Zammit112 Participants who endorsed online delivery for iEMDR and MRP also sought increased convenience, financial accessibility and mobility, Reference Strelchuk, Turner, Smith, Bisson, Wiles and Zammit112,Reference Ferkul, Agabani, Minami, Bormann, Le Foll and Lobo121 yet both groups cited privacy and confidentiality issues for iEMDR for those living with family members. Reference Strelchuk, Turner, Smith, Bisson, Wiles and Zammit112 Participants who received iEMDR initially reported safety concerns given the nature of the content and absence of the therapist onsite. Yet, therapists also reported that therapeutic alliances were established as expected despite online delivery of interventions. Reference Strelchuk, Turner, Smith, Bisson, Wiles and Zammit112
Participants suggested logistical improvements for the iEMDR, e.g. reliable computer and internet access, and additional telephone support throughout the intervention. Finally, both therapists and patients recommended the future availability of EMDR in a hybrid format. Reference Strelchuk, Turner, Smith, Bisson, Wiles and Zammit112
Message-delivered interventions
Description. Only one study investigated a message-delivered therapy, Talkspace, delivered sporadically by clinicians. Reference Malgaroli, Hull, Wiltsey Stirman and Resick114 The 12-week treatment was delivered asynchronously through multimedia messages on a health insurance interface for smartphones and computers. Therapists aimed to treat PTSD using CBT, a third-wave behavioural therapy, or psychodynamic approach.
Feasibility. Recruitment to Talkspace was reportedly 32.40% Reference Malgaroli, Hull, Wiltsey Stirman and Resick114 (Fig. 3(a)), although drop-out and completion rates were high, at 41.26 and 59%, respectively Reference Malgaroli, Hull, Wiltsey Stirman and Resick114 (Fig. 3(b) and (c)).
Acceptability. Acceptability was assessed in terms of the average numbers of messages relayed between clinicians and participants: 8.75 (s.d. = 8.88) and 14.68 (s.d. = 18.04) per week, respectively. Text messages were most common. Reference Malgaroli, Hull, Wiltsey Stirman and Resick114
Quality assessment
The quality appraisal included 49 RCTs, 11 of which were removed from the review for poor ratings, including two mixed-method studies with a qualitative assessment. Of 31 pre-post and non-randomised control studies, two were excluded for poor quality, including seven that used mixed methods. All 13 qualitative studies obtained fair or good quality ratings and were included among the 74 studies in the review. In one mixed-method study, Reference Ferkul, Agabani, Minami, Bormann, Le Foll and Lobo121 the quantitative results were excluded for a poor rating on the quantitative component, but the qualitative data were retained (see results of the quality assessment in the Supplementary Material).
Discussion
This work presents, to our knowledge, the first comprehensive review of remote technologies offered for various TSRDs. This systematic review identified a wide range of remote psychological interventions for adults with PTSD and AjD, reflecting diverse delivery methods and technological advancements: self-managed online and mobile technologies; video conferencing, which replicated face-to-face interactions; and message-based technologies, enabling sporadic communication. Although studies on remote technologies for TSRD treatment date from the early 2000s, most studies in this review appeared in 2020–2024, reflecting increased reliance on remote interventions during the COVID-19 pandemic. Reference Shafierizi, Faramarzi, Nasiri-Amiri, Chehrazi, Basirat and Kheirkhah51,Reference Bisson, Ariti, Cullen, Kitchiner, Lewis and Roberts56 Our evaluation of the feasibility and acceptability of remote interventions addresses existing gaps in PTSD and AjD treatment delivery.
The 85% of studies on PTSD in this review confirmed their preponderance in TSRD research (e.g. Reference Olthuis, Wozney, Asmundson, Cramm, Lingley-Pottie and McGrath122,Reference Simblett, Birch, Matcham, Yaguez and Morris123 ), which has been driven mainly by studies of veterans (e.g. Reference Fleuty and Almond124,Reference Jones, Miguel-Cruz, Smith-MacDonald, Cruikshank, Baghoori and Chohan125 ). Although a few recent studies have targeted AjD, Reference Fernández-Buendía, Miguel, Dumarkaite, Kazlauskas, Cuijpers and Quero38 no studies on interventions for ASD were found, highlighting that the broader literature has focused less on conditions other than PTSD. Nonetheless, these emerging studies do encompass a diverse range of remote technologies and intervention formats suitable for various patient profiles. Over three-quarters of the identified studies investigated CBT-based interventions, whereas most interventions for PTSD involved psychoeducation and symptom management, limiting their usefulness for other TSRDs, unless the latter could be adapted to the symptoms and treatment recommendations for other diagnoses. 3
Feasibility and acceptability of remote interventions
Regarding feasibility, we observed considerable variability in recruitment, drop-out and completion rates across all modalities, particularly in self-directed, online modules where retention and completion rates were lowest. Yet, the reverse patterns were observed with added clinician involvement. Drop-out rates in this review approximated those reported in other studies on remote and digital interventions, Reference Swift and Greenberg126,Reference Van Ballegooijen, Cuijpers, Van Straten, Karyotaki, Andersson and Smit127 coinciding with previous findings showing higher drop-out rates in internet-based therapies compared with face-to-face interventions. Reference Fernandez, Salem, Swift and Ramtahal128 These results suggest that challenges affecting the feasibility of remote interventions, especially those self-delivered through online platforms, are comparable across mental health diagnoses. By contrast, video conferencing modalities produced drop-out rates comparable to face-to-face interventions, Reference Imel, Laska, Jakupcak and Simpson129 suggesting that feasibility in remotely delivered interventions may be linked not only with the modality used, but also with other factors like accountability; that is, responsibility for completion of the intervention. Reference Werntz, Silverman, Behan, Patel, Beltzer and Boukhechba130 Accountability also increased with clinician involvement. Reference Rathenau, Sousa, Vaz and Geller131 The integration of reward mechanisms proved effective in increasing participant accountability, especially in self-directed interventions, as suggested in Possemato et al, Reference Possemato, Acosta, Fuentes, Lantinga, Marsch and Maisto117 e.g. engaging individuals in their own progress by integrating their feedback on progress and rewards. Reference Cheng, Davenport, Johnson, Vella and Hickie132 These reward mechanisms, borrowed from game-based characteristics for increased user motivation and engagement, Reference Deterding, Dixon, Khaled and Nacke133 have improved mental health outcomes while addressing adherence and drop-out issues (see Reference Primack, Carroll, McNamara, Klem, King and Rich134,Reference Brown, ONeill, van Woerden, Eslambolchilar, Jones and John135 ). PTSD Coach is one application that successfully integrated gamification components to enhance user engagement. Reference Owen, Jaworski, Kuhn, Makin-Byrd, Ramsey and Hoffman136
Overall, most participants reported high satisfaction with the interventions they received Reference Quero, Rachyla, Molés, Mor, Tur and Cuijpers77,Reference Spence, Titov, Dear, Johnston, Solley and Lorian80 and were willing to recommend them to others. Reference Spence, Titov, Johnston, Jones, Dear and Solley53,Reference Dumarkaite, Truskauskaite-Kuneviciene, Andersson, Mingaudaite and Kazlauskas58 A few studies reported high levels of therapeutic alliance or satisfaction with clinician involvement, Reference Klein, Mitchell, Abbott, Shandley, Austin and Gilson67,Reference Lehavot, Millard, Thomas, Yantsides, Upham and Beckman69 viewed as increasing motivation, engagement and potential acceptability of the intervention. Reference Bragesjö, Ivanov, Andersson and Rück48,Reference Shafierizi, Faramarzi, Nasiri-Amiri, Chehrazi, Basirat and Kheirkhah51 One study using a prolonged exposure protocol reported adverse emotional effects, Reference Bragesjö, Arnberg, Särnholm, Olofsdotter Lauri and Andersson57 suggesting the possible need for clinician involvement to support users during emotionally demanding interventions. Results suggested that access to a clinician throughout treatment may increase acceptability, particularly with interventions using highly emotional components (e.g. prolonged or narrative exposure). Online modules could also be used as stepping stones to treatment-seeking, while offering interventions that ensure flexible access.
Previous research has identified an association between engagement, viewed as participants’ interest in, or use of, a given intervention, and the efficacy of digital mental health interventions for trauma recovery, Reference Yeager and Benight137 which could be enhanced by clinician involvement. Therapeutic alliance also plays a role in psychotherapeutic treatment outcomes for PTSD, Reference Howard, Berry and Haddock138 suggesting another reason for involving clinicians depending on the clinical needs of users.
Strengths and limitations
This systematic review presented certain limitations that should be considered. First, as the review excluded grey literature in favour of peer-reviewed studies only, as higher-quality research, some more recent investigations may have been overlooked. Additionally, the review considered only English and French studies, foregoing potentially insightful publications in other languages. However, as most scientific publications appear in English and a thorough search in multiple databases was conducted, we are confident that the review maximised the inclusion of relevant studies. Second, most studies were conducted on veterans, yielding results that may not translate easily to other populations (e.g. civilians, humanitarian workers), thus limiting the generalisability of the findings. Also, acceptability and satisfaction reports were based solely on intervention completers, thus excluding the perspectives of those who dropped out of treatment, who would provide crucial insights for understanding the acceptability of remote interventions. Thus, the conclusions related to acceptability should be interpreted with caution, and future studies should incorporate drop-out acceptability ratings whenever possible. Finally, although this review investigated many TSRDs, PGD was excluded. Although PGD is increasingly recognised as a TSRD in both the ICD-11 and DSM-5-TR, our decision to exclude it was based on the need for conceptual clarity and feasibility. PGD presents with a distinct set of symptoms (e.g. intense yearning, identity disruption) and may involve different therapeutic targets, Reference Killikelly and Maercker7 warranting a separate review. We acknowledge this as a limitation and recommend that future work explores digital interventions for PGD.
Despite these limitations, this mixed systematic review offers many strengths, like the inclusion of qualitative, quantitative and mixed-method research designs, which supported a thorough and comprehensive account of the different modalities available for PTSD and AjD. Additionally, the inclusion of multiple remote modalities allowed us to highlight their commonalities and differences, which is critically important in drawing clinical recommendations.
Recommendations
Roberts and Nixon Reference Roberts and Nixon139 recently proposed a PTSD-focused, stepped-care approach for the treatment of PTSD, which was successfully implemented by the US Department of Veteran Affairs as a variation of PTSD Coach. Reference Feder, Kowalchyk, Brinkman, Cahn, Aaronson and Böttche85,Reference Niemeyer, Knaevelsrud, Schumacher, Engel, Kuester and Burchert90 Based on the key findings from this review, we adapted the Robert and Nixon approach to propose ways of ensuring the scalability and accessibility of interventions for TSRDs with a focus on individualised care, feasibility and acceptability of digital interventions. Reference Hitchcock and Fitzpatrick140 We suggest that certain intervention modalities may be better suited to particular clinical elements (e.g. therapeutic goals, symptom severity) and individual profiles (e.g. level of autonomy, engagement or motivation) (Fig. 4). For instance, clinician-guided online interventions and video conferencing interventions showed higher retention rates, suggesting that they motivated participants to engage with the intervention, and, moreover, that individuals with high clinical needs and low intrinsic motivation should be referred for remote interventions involving clinicians. By contrast, treatment for individuals who value flexibility and have the ability to go at their own pace should prioritise options like self-directed interventions, which offer greater autonomy. This adapted stepped-care approach could be achieved by developing an algorithm based on symptom severity and individual needs which could suggest various modalities based on feasibility and acceptability, and then provide additional information on how to access these interventions and modalities. The utility and feasibility of such an algorithm could then be tested in various contexts, such as among treatment-seeking individuals accompanied by their healthcare providers, or those using self-guided algorithms.
Fig. 4 Clinical recommendations for remote modalities according to individual needs.
Supplementary material
The supplementary material is available online at https://doi.org/10.1192/bjo.2025.10832
Data availability
Data availability is not applicable to this article as no new data were created or analysed in this study.
Acknowledgements
The authors would like to acknowledge the help and support of Christina Paquette in the quality appraisal of the articles and Judith Sabetti for assistance in editing this manuscript.
Author contributions
M.R.-B. contributed to study conceptualisation, methodology, formal analysis, writing the original draft of the manuscript and reviewing and editing the manuscript. J.F. contributed to study conceptualisation, methodology, formal analysis and writing the original draft of the manuscript. É.G. contributed to formal analysis and reviewing and editing the manuscript. M.L. contributed to study methodology and reviewing and editing the manuscript. A.B. contributed to study conceptualisation, supervision and reviewing and editing the manuscript. M.F. contributed to study conceptualisation, methodology, supervision, writing the original draft of the manuscript and reviewing and editing the manuscript.
Funding
This research received no specific grant from any funding agency, commercial or not-for-profit sectors.
Declaration of interest
None.
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