Moral Injury, Chaplaincy and Mental Health Provider Approaches to Treatment: A Scoping Review

The aim of this research was to describe the evidence examining the approaches taken by mental health providers (MHPs) and chaplains to address symptoms related to moral injury (MI) or exposure to potentially morally injurious events (PMIEs). This research also considers the implications for a holistic approach to address symptoms related to MI that combines mental health and chaplaincy work. A scoping review of literature was conducted using Medline, PsycINFO, Embase, Central Register of Controlled Trials, Proquest, Philosphers Index, CINAHL, SocINDEX, Academic Search Complete, Web of Science and Scopus databases using search terms related to MI and chaplaincy approaches or psychological approaches to MI. The search identified 35 eligible studies: 26 quantitative studies and nine qualitative studies. Most quantitative studies (n = 33) were conducted in military samples. The studies examined interventions delivered by chaplains (n = 5), MHPs (n = 23) and combined approaches (n = 7). Most studies used symptoms of post-traumatic stress disorder (PTSD) and/or depression as primary outcomes. Various approaches to addressing MI have been reported in the literature, including MHP, chaplaincy and combined approaches, however, there is currently limited evidence to support the effectiveness of any approach. There is a need for high quality empirical studies assessing the effectiveness of interventions designed to address MI-related symptoms. Outcome measures should include the breadth of psychosocial and spiritual impacts of MI if we are to establish the benefits of MHP and chaplaincy approaches and the potential incremental value of combining both approaches into a holistic model of care.


Introduction
Moral injury (MI) refers to the enduring psychosocial and spiritual harms that can result from exposure to situations or events that occur in high stakes situations and involve transgression of one's deeply held moral convictions of right and wrong, or perceived betrayal by those in positions of authority. (Litz et al., 2009;Shay, 2014). These events are described as potentially morally injurious events (PMIEs), recognizing that not everyone exposed will be impacted in the same way. Evidence from a range of studies in United States (US) military samples suggests that individuals exposed to PMIEs are at greater risk of developing mental health issues, including more severe post-traumatic stress disorder (PTSD), depression, anxiety, and suicidality (summarized in Koenig & Al Zaben, 2021).
Although symptoms often co-occur and can overlap with PTSD, MI appears to be functionally distinct from PTSD (Farnsworth et al., 2017;Shay, 2014). Studies conducted with active military personnel have specifically distinguished MI symptom profiles from PTSD with respect to guilt, self-blame, and shame, rather than gaps in memory of trauma, flashbacks, and nightmares (Bryan et al., 2018;Litz et al., 2018). There may also be different causal mechanisms involved in MI and PTSD at the neurophysiological level (Barnes et al., 2019).
There has been a surge of interest in MI research in recent years focusing on efforts to understand and frame the construct of MI and the prevalence of MI in diverse populations (e.g., military personnel, veterans, police and other first responders), recently including healthcare workers in the context of the COVID-19 pandemic (Koenig & Al Zaben, 2021). The research has been led by mental health-related disciplines (e.g., psychology, psychiatry) as well as spiritual and religious disciplines (e.g., chaplaincy), all of which have played important roles in conceptualizing and developing approaches to address MI. Standard interventions for PTSD, such as Prolonged Exposure (PE), may be helpful for addressing some of the psychological distress associated with exposure to PMIEs (e.g., Paul et al., 2014;Wachen et al., 2016); nevertheless, new intervention approaches directly targeting the specific causes and consequences of MI may also benefit some patients (e.g., Gray et al., 2012;Maguen et al., 2017). There is evidence that spiritually integrated psychotherapies, as well as chaplain facilitated pastoral care approaches, may be effective adjuncts or alternatives for addressing MI (e.g., Carey & Hodgson, 2018;Cenkner et al., 2021). The potential benefits of these approaches may be associated with addressing the spiritual impacts of moral transgressions (Carey et al., 2016;Koenig & Al Zaben, 2021).
Despite the proliferation of research into MI as a construct, there is a dearth of literature examining the effectiveness of MHP or chaplaincy intervention approaches. An early integrated narrative review of MI interventions by Griffin et al. (2019) identified studies using: (1) extant and adaptations of extant Journal of Religion and Health (2022) 61:1051-1094 interventions for PTSD (i.e., Prolonged Exposure [PE], Cognitive Processing Therapy [CPT], Spiritually Integrated CPT); (2) alternative and adjunctive interventions for MI (i.e., Acceptance and Commitment Therapy, Adaptive Disclosure, Impact of Killing); and (3) interventions integrating spirituality (i.e., Building Spiritual Strength). The review identified some evidence for Adaptive Disclosure and Impact of Killing in addressing MI, but most of the intervention approaches were not associated with efficacy or effectiveness trials (Griffin et al., 2019). Since that time, the evidence base has increased to include several intervention trials, including trials of relatively novel interventions.
A recent narrative review by Harris et al. (2021) identified eight spiritually integrated interventions for PTSD and MI, including an updated summary of the available evidence base. While this review included three interventions that target MI (Adaptive Disclosure, Impact of Killing and Building Spiritual Strength) other intervention approaches used by mental health professionals and chaplains to address MI were not included. A second narrative review (Koenig & Al Zaben, 2021) identified several additional psychological approaches, spiritual/religious integrated approaches and pastoral care approaches. This review provided a brief description of the available approaches to MI but did not present evidence of intervention effectiveness.
Thus, despite these recent reviews, there appears to be a gap in the MI literature that can be addressed by a review employing a systematic methodology to identify the currently available psychological, chaplaincy, and integrated approaches to addressing MI, alongside a systematic summary of evidence of effectiveness. The current scoping review was designed to systematically identify and map the approaches taken by MHPs and chaplains to address moral injury, including any evidence of effectiveness.

Method
A scoping review was conducted involving a systematic search of studies examining MHP and/or chaplaincy approaches to support adults who have experienced MI or been exposed to PMIEs (Arksey & O'Malley, 2005). The review adhered to the PRISMA Extension for Scoping Reviews: Checklist and Explanation (PRISMA-ScR) statement (Tricco et al., 2018).

Identifying Relevant Studies
Searches were conducted on 11 electronic databases (Medline, PsycINFO, Embase, Central Register of Controlled Trials, Proquest, Philosphers Index, CINHAL, SocINDEX, Academic Search Complete, Web of Science and Scopus) combining terms related to MI and chaplaincy approaches or psychological approaches to MI (See Appendix 1 for search strategy). Manual searches of the reference lists of key relevant studies were conducted to identify any additional relevant publications. The search strategy included all publication types except for conference abstracts, published from database inception until August 2021.

Study Inclusion and Exclusion Criteria
Eligible studies included any research designs that reported on either MHP approaches or chaplaincy approaches to support adults reporting MI symptoms or exposure to a PMIE. The research designs included case studies, pilot studies, or trials of interventions reporting on intervention efficacy, as well as qualitative descriptive studies or qualitative evaluations of interventions. Studies were restricted to English language, peer-review journals, and unpublished dissertations. The search excluded conceptual studies that reported on untested recommendations or interventions to address MI, protocols of ongoing clinical trials, or interventions that were not delivered by MHPs or chaplains.
Following a pilot test of eligibility criteria, records were initially screened on title and abstract by one reviewer (I.F.), with 20% of studies screened by a second reviewer (K.J.). All records not excluded on the basis of title and abstract were passed on for full-text review. Two reviewers (I.F. and K.J.) independently reviewed full-text records for potentially eligible studies. Any disagreements at the full-text screening stage were resolved by discussion, or through adjudication with a third reviewer (A.P.). Records deemed ineligible at full-text screening were excluded with the reason recorded. All screening was conducted using the systematic review management tool Covidence (Covidence Systematic Review Software).

Data Charting
Data were charted using a standardized data collection form by a single reviewer, capturing information on key study characteristics. The data collection form included author, year, title, study setting, study design, population, sample size, data collection methods, intervention characteristics (e.g., intervention name, duration, number of sessions, session details), outcomes, and important findings. The intent of this scoping review was to ascertain the size and scope of the available literature. No appraisal was conducted of evidence quality.

Summarizing and Reporting Findings
Results were summarized using a narrative descriptive synthesis approach (Khalil et al., 2016) with evidence from quantitative and qualitative studies categorized according to the facilitator (i.e., MHPs, chaplains, and combination of MHPs and chaplains) and were supported by a table of key study characteristics. Summaries related to study setting and population, psychological or chaplaincy approaches, along with outcomes assessed and broad key findings.

Search Results
Electronic searches yielded 14,986 records, with 5705 of these (minus duplicates) screened on the basis of title and abstract. Of these, 196 were subject to full-text review, with 31 studies deemed eligible for inclusion in the current scoping review. Six additional records were identified through manual citation searches, four of which were deemed eligible for inclusion. Overall, 35 studies (n = 26 quantitative; n = 9 qualitative) were included in the review (see Table 1).

Study Characteristics
A total of 26 quantitative studies were identified consisting of 11 case studies, 8 pre-post studies, 6 randomized control trials (RCTs), and a single program evaluation using pre and post measures. Most studies (k = 23, 88%) originated from the United States, with single studies from Canada, United Kingdom and the Netherlands. Studies were mostly conducted with military samples (k = 24, 92%) and involved male personnel (88% of studies comprised 70% or more male personnel). Most studies examined interventions delivered by MHPs (65%, k = 17), three studies (12%) examined interventions delivered by chaplains, and six studies (23%) examined interventions co-delivered by MHP and chaplains (see Table 1). Most studies assessed changes in PTSD (k = 22, 85%) and depression scores (k = 13, 50%) to determine intervention outcome. A smaller number of studies (k = 8, 31%) assessed MI as an outcome, variously using the Moral Injury Events Scale (k = 3), the Moral Injury Symptom Scale-Military (k = 2), the Moral Injury Attributions Scale (k = 1), the Expressions of Moral Injury Scale (k = 1) and Cognitive Fusion Questionnaire-Moral Injury (k = 1). There were five studies (19%) that assessed religious struggles or spiritual distress as an outcome.
A total of nine qualitative studies were identified. Most qualitative studies (k = 7, 78%) originated from the United States, with two studies from the United Kingdom (22%). All qualitative studies were conducted within a military setting, including mental healthcare service settings (e.g., a VA Medical Center, k = 9, 89%), with a single study at a national VA Chaplain Center. Most qualitative studies included military personnel (veterans or active-duty personnel) completing psychotherapies for PTSD or MI (k = 4, 44%), with a smaller proportion including mental health practitioners working with veterans with PTSD and PMIE exposures (k = 3, 33%), or chaplains providing care to veterans with MI or spiritual distress (k = 2; 22%) (see Table 1).

Study Themes
Using a narrative descriptive synthesis approach, six key themes emerged: 1) Mental health practitioner approaches to MI; 2) Interventions for PTSD; 3) Adjunctive CPT without the written account of the trauma • AD was found to be non-inferior to CPT-C, with no difference found between CAPS total severity change score between AD and CPT-C   Regardless of trauma type, individuals completing the individual mode of CPT-C reported better mental health outcomes than those completing group CPT-C   who work with veterans exposed to PMIEs

MHP Approaches to MI
There were two qualitative studies that examined MHP approaches to supporting military personnel with MI-related mental health problems. Several different approaches were reported, with no consensus between clinicians on the best intervention approach (Williamson et al., 2019(Williamson et al., , 2021. Most of the quantitative studies identified in the search (17 of 26) assessed interventions facilitated by MHPs to address MI. These included: (1) interventions for PTSD using standard evidence-based PTSD interventions (PE, CPT; five studies), adapted PTSD interventions (CPT, Cognitive Therapy, Brief Eclectic Psychotherapy; three studies), or emerging PTSD interventions (Multi-modular Motion-assisted Memory Desensitization and Reconsolidation, Trauma Informed Guilt Reduction; two studies); (2) interventions targeting MI as an adjunct to standard intervention for PTSD (Impact of Killing, Self-forgiveness: Addressing MI; two studies) or as alternatives to standard intervention for PTSD (Adaptive Disclosure, Acceptance and Commitment Therapy; four studies); and (3) a non-psychological intervention (Warrior Journey Retreat; one study). Details of the studies are provided in the following section.

Standard Evidence-Based PTSD Interventions
A number of studies have investigated the efficacy of standard evidence-based PTSD interventions for the treatment of MI. Two of these standard PTSD intervention efficacy studies compared mental health and wellbeing symptom reduction in those who had experienced traditional PTSD-related traumas such as fear and/or loss in combat, compared to those who had experienced MI-related index traumas such as causing or witnessing civilian casualties.
Two case studies found reductions in PTSD and depression symptoms for US veterans with MI-related injurious index traumas following standard PE and CPT (Held et al., 2018;Paul et al., 2014). One study assessed the effectiveness of an intensive outpatient PTSD program (massed-CPT), consisting of group CPT and individual CPT (in conjunction with mindfulness and yoga sessions) and found similar trajectories for PTSD and depression symptoms in veterans endorsing MI-related PTSD (e.g., history of MI; index trauma involved a PMIE) compared to those with PTSD without a PMIE exposure (Held et al., 2021). Another case study found reductions in PTSD but no change in depression symptoms, following massed-PE in US active-duty personnel with MI-related index traumas (Evans et al., 2021). Finally, a secondary analysis of an RCT comparing individual and group CPT (without the written accounts) identified no difference in symptoms of PTSD, depression, anxiety or suicide ideation in US active-duty personnel endorsing a MI-related index trauma (committing, witnessing or being the victim of acts perceived to be gross violations of moral or ethical standards) compared to those with other trauma types (e.g., exposure to threat of death of self or others, aftermath of violence, or traumatic loss) (Hawkins, 2021).
Of interest, a qualitative study of veterans with exposure to a PMIE who had completed PE or CPT, reported that MI was not identified or sufficiently discussed during therapy and that the intervention had little impact on MI during or after intervention (e.g., did not target guilt or shame, had no long lasting impact on functioning) (Borges et al., 2020).

PTSD Interventions Adapted for MI
The literature review identified three PTSD interventions that have been adapted specifically to address MI: CPT, Cognitive Therapy and Brief Eclectic Psychotherapy. CPT for PTSD has been adapted in a 12-session Spiritually Integrated CPT (SI-CPT) intervention. SI-CPT focuses on challenging maladaptive thinking patterns through gradual exposure, cognitive processing and cognitive restructuring. To accommodate the potential for appropriate or legitimate selfblame or guilt following a PMIE, cognitive restructuring within SI-CPT challenges interpretations of trauma that serve to maintain distress, using spiritual resources (e.g., mercy, repentance, forgiveness, spiritual surrender, prayer/contemplation, divine justice, hope, and divine affirmations), and rituals (e.g., confession, penance). Quantitative evidence for SI-CPT is limited to a single case study (Pearce et al., 2018), which demonstrated improvements in PTSD symptoms for a veteran with PTSD associated with a PMIE.
Cognitive Therapy has also been examined as a potential intervention approach to address MI in the context of PTSD (CT-PTSD Addressing MI; Murray & Ehlers, 2021). A single case study of a British doctor with MI-related PTSD reported improvements in symptoms of PTSD, depression and functioning following CT-PTSD. The intervention involved psychoeducation on MI, incorporating reclaiming values and self-identity, discussing shame and guilt prior to accessing the traumatic memory, identifying and addressing distorted or over-generalized appraisals within the trauma memory, and acceptance and moving on (e.g., acts of reparation).
Lastly, Brief Eclectic Psychotherapy for Moral Trauma is a 16-session individual cognitive-behavioral, psychodynamic, constructivist, and systemic psychotherapy including psychoeducation, gradual imagery exposure to the moral trauma, mementos and writing tasks, and processing of thoughts and emotions (including shame and guilt). Evidence to date is restricted to a single case study of a male refugee with PTSD and history of military service in his home country. The case study reported improvements in PTSD and MI appraisals after completing the intervention (de la Rie et al., 2021).

Emerging PTSD Interventions Adapted for MI
Emerging PTSD interventions that have been used to address MI include Trauma Informed Guilt Reduction (TrIGR) and Multi-modular Motion-assisted Memory Desensitization and Reconsolidation (3MDR). TrIGR is a 4-7-session transdiagnostic psychotherapy used to address guilt, shame, and MI stemming from combat-related traumatic experiences. Patients are encouraged to accurately appraise their trauma-related guilt, taking into account the full context in which the event occurred and taking steps towards leading a meaningful life through re-engaging with their values. A pilot study of TrIGR in 10 US veterans (Norman et al., 2014) found clinically significant improvements in PTSD symptoms. Finally, 3MDR, an emerging virtual reality-based therapy for PTSD, has also been found to significantly reduce PTSD and MI symptom severity based on a crossover RCT of 40 Canadian veterans and active-duty personnel (Jones et al., 2020).

Adjunctive and Alternative Psychotherapies for MI
Another body of research highlights interventions that have been specifically developed to address MI. These include two interventions intended as an adjunct to standard interventions for PTSD (Impact of Killing and Self-forgiveness: Addressing MI) and two alternative interventions (Active Disclosure and Acceptance and Commitment Therapy).
Impact of Killing is a 6-8 session, cognitive-behavioral intervention that has an explicit focus on the act of killing, as a PMIE involving transgression of personal or shared morals and leading to MI (Burkman et al., 2021). Empirical evidence to date assessing Impact of Killing is limited to a pilot RCT of 35 veterans who had previously completed standard treatment for PTSD (Maguen et al., 2017), which found the intervention to be both helpful and acceptable. In addition, veterans in the Impact of Killing condition reported statistically significant greater improvements in PTSD symptoms, general psychiatric symptoms (e.g., depression, anxiety) and functioning (e.g., greater participation in community events) relative to the wait-list control condition. Qualitative evidence has supported the acceptability and feasibility of the Impact of Killing in a veteran sample (Purcell et al., 2018) and a sample of mental health practitioners . Further, these studies found that the intervention addressed a clinical need that was not met by other standard interventions for PTSD.
Self-forgiveness: Addressing MI is a brief 4-session intervention that involves: (1) psychoeducation on forgiveness, shame, and guilt; (2) the identification of violated values, moral and beliefs; and (3) written accounts of trauma exposure. A non-randomized trial comparing group CPT and group CPT plus the self-forgiveness modules (Snider, 2015) indicated no significant difference between the two conditions on PTSD as an outcome, with both showing significant reductions in PTSD symptoms. However, veterans completing the self-forgiveness modules reported significantly higher feelings and actions related to self-forgiveness in comparison to the veterans completing group CPT only.
Adaptive Disclosure has been proposed as an alternative intervention for MI. Adaptive Disclosure is an emotion-focused, cognitive-behavioral therapy with 6and 8-session protocols developed specifically for active-duty military personnel (Litz et al., 2021). The intervention is designed to flexibly address MI, traumatic loss and grief, or the impacts of life-threatening experiences. It involves psychoeducation, imaginal exposure, and experiential processing. In comparison to standard PE, the exposure components of Adaptive Disclosure focus on identifying distressing appraisals and cognitions rather than fear extinction, and standard cognitive restructuring exercises are largely replaced with experiential exercises (Litz et al., 2021). Adaptive Disclosure has been tested in a pilot open trial (Gray et al., 2012) and a non-inferiority RCT (Litz et al., 2021). In the preliminary open trial of 44 active-duty US military personnel, significant improvements were found for PTSD symptoms, depression symptoms, post-traumatic cognitions and post-traumatic growth (Gray et al., 2012). Results from the noninferiority RCT with 122 active-duty US military personnel, evidenced reductions in PTSD symptoms in the Adaptive Disclosure condition to be comparable to reductions from CPT-Cognitive Therapy version.
Acceptance and Commitment Therapy (ACT) is a transdiagnostic intervention that has been proposed as a promising intervention for MI. ACT can be delivered individually or in group, in person or via telehealth, and over 8 or 12 sessions. The intervention focuses on openness, awareness and engagement to (1) foster psychological and behavioral flexibility; (2) promote acceptance of experiences; and (3) promote commitment to actions toward value-based behavior (Walser & Wharton, 2021). Evidence from a pre-post study of 33 US veteran participants receiving ACT in a group setting indicated a favorable response with statistically significant reductions in symptoms of PTSD and depression, as well as enhanced self-reported wellbeing. Unfortunately, intervention effects were not maintained to follow-up (Bluett, 2017). Evidence from a case study of ACT delivered via telehealth also indicated a favorable response with statistically significant reductions in symptoms of PTSD and depression. (Borges, 2019). In addition, 11 US veterans in a PTSD residential treatment program reported benefits from group ACT intervention, and indicated that they would recommend ACT to other veterans (Farnsworth et al., 2017).

Non-psychological Interventions for Moral Injury
Warrior Journey Retreat is a 5-day grieving retreat involving guided introspection, body-based mindfulness, expressive arts and group sharing. Evidence from a single pre-post study reported clinically significant improvements in PTSD symptoms in seven of eight US veterans who completed the Warrior Journey Retreat (Artra, 2013).

Chaplaincy Approaches to MI
The literature search identified two qualitative studies assessing chaplain's experiences of providing spiritual care to veterans with MI. The studies explored what support was provided, and how effective chaplains' approaches were in helping veterans address spiritual distress. Chaplains reported using both religious and non-religious approaches, comprising pastoral care (e.g., spiritual counseling, religious scripts, listening), and therapeutic processes (e.g., psychoeducation, meditation and mindfulness, emotional processing, narrative therapy) (Chang et al., 2015;Drescher et al., 2018). Chaplains reported success in helping veterans with spiritual distress, particularly when the distress stemmed from religion, but also acknowledged the need for referrals to mental health practitioners to address the psychological aspects of spiritual distress (Chang et al., 2015).
There were also three quantitative studies of chaplaincy approaches used to address MI. The Mental Health Clinician Community Chaplain Collaboration (MC4) is a 6-12-week, individual, spiritual-based counseling intervention that focuses on forgiveness of a higher power, of others and of self, as well as community reintegration through both community connection and community service to make amends. Evidence from a feasibility study with 13 US veterans found MC4 to be feasible and acceptable to participants (Pyne et al., 2021), however there were minimal improvements in PTSD symptoms, psychological distress, self-forgiveness, guilt and shame. Veterans reported the following components of MC4 as beneficial: spiritual focus of the intervention (92%); emotional support (76%); non-judgmental manner of facilitators (i.e., pastors, chaplains, or community clergy) (69%); shared combat experience (46%) and spiritual beliefs (38%) of facilitators. Approximately one-third of participating veterans reported the lack of mental health training of facilitators as a limitation of MC4.
The Structured Chaplain Intervention is a 12-session, structured bio-psychosocial-spiritual intervention enabling veterans to process trauma using a spiritual lens. Topics include dimensions of MI, such as feeling betrayed, guilt, shame, moral concerns, religious struggles, loss of religious faith/hope, loss of trust, loss of meaning/purpose, difficulty forgiving and self-condemnation. A case study with two US veterans participating in an ongoing RCT of the Structured Chaplain Intervention provided preliminary low certainty evidence suggesting improvements in symptoms of PTSD as well as MI (Ames et al., 2021).
The Warrior's Journey Intervention (unrelated to the Warrior Journey Retreat mentioned above) is a narrative meaning-making intervention, intended to motivate treatment seeking in veterans experiencing symptoms of PTSD. Chaplains share a spiritual, metaphoric adventurous story of trauma recovery, designed to impact on hope, meaning and guilt. A single case study (Fleming, 2020) provided low certainty evidence suggesting improved motivation for help-seeking and symptom relief in a veteran who completed the single session Warrior's Journey Intervention.

MHP and Chaplains-Combined Approaches to MI
The literature search identified three interventions that combined psychological and chaplaincy approaches to addressing MI and these were assessed in six studies. Building Spiritual Strength (BSS) is an eight-session group-based counseling intervention specifically designed to reduce symptoms of PTSD and promote psychospiritual development by encouraging participants to actively address their MI-related distress using pre-existing spiritual resources . The components of BSS include reframing, discussing evil in the world, and using meditation and prayer as an active coping strategy. Evidence for the effectiveness of BSS in addressing MI symptoms comes from a case study (Harris et al., 2015) and two RCTs (Harris et al., 2011(Harris et al., , 2018. The case study of a US veteran with PTSD and depression indicated short-term symptom relief (e.g., reduced self-loathing) and improved motivation for help-seeking (Harris et al., 2015). The first RCT involving 54 US veterans (Harris et al., 2011), reported statistically significant reductions in PTSD symptoms at postintervention in veterans in the BSS group relative to those in the wait-list control. The second RCT of 138 US veterans and active-duty personnel (Harris et al., 2018) used Present-centered Group Therapy as a control condition. The authors found that both groups demonstrated a clinically and statistically significant improvement in PTSD symptoms; however, participants in the BSS condition showed improvements in spiritual distress while those who received Presentcentered Group Therapy reported increases in spiritual distress.
Moral Injury Group, is a 12-session intervention incorporating psychoeducation focused on components of morality (i.e., MI, moral emotions, moral values, moral dilemmas, and moral disengagement) and spiritual practices integrated within the Community Ceremony, and consisting of music, ritual and spiritual discipline. The Community Ceremony offers an opportunity for Veterans to testify about their MI experience and challenge the community to 'express responsibility' for those sent to war on their behalf, through ceremonial ritual such as lighting "Candles of Lament" (visible reminders of people who died in warfare), the Reconciliation Circle (veterans surround non-veterans in a symbolic circle of protection, followed by nonveterans surrounding veterans, symbolic of 'having the backs' of veterans), a water cleansing ritual (handwashing and prayer), and Candles of Hope (candles are taken by non-veterans as a symbol of shared responsibility). A single case study of a US veteran found improvements in depression, religious struggles, self-compassion, and social functioning (Antal et al., 2019). Evidence from a proof-of-concept study with 40 veterans indicated high rates of completion, with small to moderate improvements in depression, psychological wellbeing, religious struggles, post-traumatic growth and self-compassion at postintervention. (Cenkner et al., 2021).
The Search for Meaning Program has been implemented within a Veteran Affairs (VA) Medical Center in the USA since 2012 (Starnino et al., 2019). The Search for Meaning Program is an 8-session group intervention involving spirituality-and mindfulness-based PTSD psychoeducation. Topics include spiritual wounding and subsequent emotions (e.g., anger, sadness, betrayal, hopelessness), impact of trauma on core beliefs, avoidance, meaning-making processes, strategies to address anger and grief, and forgiveness. A preliminary evaluation of 24 US veterans completing the Search for Meaning Program at the VA Medical Center found significant improvements in PTSD symptoms, spiritual injury and negative religious coping (Starnino et al., 2019). A qualitative study involving interviews with 18 US veterans following completion of the Search for Meaning Program reported that the veterans found the intervention to be helpful but not sufficient to enable them to make meaning from their PMIE (Starnino et al., 2019(Starnino et al., , 2020.

Discussion
This scoping review provides an overview of the literature describing the approaches taken by MHPs and chaplains to address MI, as well as a summary of the published evidence to date regarding the effectiveness of each approach. Despite rapid growth in interest in the construct of MI and exponential growth in the literature describing the experience of MI within different populations, there are still very few RCTs (k = 6) or pre-post studies (k = 8), that have been designed to assess the effectiveness of interventions for MI.
The emerging evidence includes studies that have investigated a variety of different approaches to MI designed to be delivered by MHPs. These include standard PTSD interventions (PE and CPT), an adjunctive intervention (Impact of Killing) and two alternative interventions (Adaptive Disclosure and Acceptance and Commitment Therapy).
While several studies found PE and CPT to be acceptable, feasible and effective for symptoms of PTSD in those with MI, a qualitative study found that the interventions had limited impact on MI-related symptoms, and for some participants, benefits were not maintained (Borges et al., 2020). As a result, individuals with a history of PMIE exposure, who receive standard PTSD interventions may not experience any sustained reduction in distress associated with MI-related symptoms such as shame, loss of trust, and guilt. This possibility is theoretically congruent as violation of one's morals or ethics is not typically addressed within standard TF-CBT. Relatedly, event reappraisals, a component of standard TF-CBT PTSD interventions, may be less relevant for MI wherein the accurate appraisal is a causal mechanism of distress. Interventions that promote self-forgiveness and forgiveness of others may be more effective in addressing MI (Litz et al., 2009;Maguen et al., 2017;Steinmetz & Gray, 2015).
There is emerging evidence for MHP-delivered interventions that are designed to be delivered as an adjunct to standard PTSD interventions and specifically target symptoms associated with exposure to PMIEs. The feasibility, acceptability and potential effectiveness of Impact of Killing as an adjunctive therapy for MI was supported by a small pilot study (Maguen et al., 2017) and two qualitative studies Purcell et al., 2018). Evidence from uncontrolled studies suggested that Acceptance and Commitment Therapy may reduce PTSD and depression symptoms as well as enhance general wellbeing in individuals who had been exposed to a PMIE; however results from a rigorous longitudinal study indicated that benefits in MI-related outcomes were not sustained and in fact some symptoms increased from baseline to one-month post intervention Bluett (2017), thus additional longitudinal trials -ideally RCTs-are needed. Finally, Adaptive Disclosure has been found in an open pilot trial (Gray et al., 2012) and a non-inferiority trial against CPT-C (Litz et al., 2021) to improve PTSD and depression symptoms in active-duty military personnel with PTSD. There was no long-term follow up data in either study, so the sustainability of intervention effects remain unknown.
Other MHP-delivered interventions with less evidence to date include Brief Eclectic Psychotherapy for Moral Trauma, Cognitive Therapy, Trauma Informed Guilt Reduction, Self-forgiveness: Addressing MI, Multi-modular Motion-assisted Memory Desensitization and Reconsolidation, and the Warriors Journey Retreat. Studies assessing the effectiveness of these interventions varied in methodological rigor and more research is required before we can be confident in their effectiveness.
The scoping review identified two chaplain-delivered interventions for which evaluations have been published, the Structured Chaplain Intervention and the Mental Health Clinician Community Chaplain Collaboration. However, both evaluations were based on case studies, providing low certainty evidence. The paucity of evidence for chaplaincy approaches to MI does not indicate that chaplains are not addressing MI. A large qualitative study of 245 US Veterans Affairs chaplains reported that chaplains working with veterans exposed to PMIEs draw on a broad range of therapeutic interventions including religious/spiritual-based approaches and psychotherapeutic approaches (Drescher et al., 2018). The potential for combined psychological and chaplaincy approaches has been showcased in the combined approaches described in this review with initial evidence of small to moderate intervention effects. There is, however, considerable room for further development and testing of combined approaches to addressing MI.
One of the most obvious shortcomings in the MI intervention literature included in the current scoping review, is the absence of comprehensive and validated change measurements specific to diverse MI outcomes. MI involves broad psychosocial and spiritual outcomes, including emotions (e.g., guilt, shame, anger), self-perception, interpersonal functioning and spiritual/existential beliefs (Yeterian et al., 2019). Yet most of the studies included in the review relied on changes in PTSD and depression symptoms to assess the effectiveness of MI interventions. A small number of studies assessed MI outcomes using three different MI measures: Moral Injury Appraisals Scale, which focuses on cognitive appraisal of PMI experiences; Moral Injury Event Scale (MIES), which is intended to measure PMIE exposures rather than MI outcomes; and Moral Injury Symptom Scale Military which measures some but not all MI outcomes. Unfortunately, none of these measures were developed using best practice test construction and validation approaches, relying instead upon the compilation of items from existing scales and informed assumptions regarding the nature of MI symptoms (Yeterian et al., 2019). A validated measure of MI outcomes that captures the full spectrum of MI across psychosocial and spiritual domains developed following best practice methodology including input from the target population and designed to assess MI symptoms in a broader population than just military personnel or veterans is needed to properly assess the impacts of psychological and chaplaincy approaches to MI and whether there is incremental utility in a combined approach. The routine use of such a measure, alongside measures of PTSD and depression symptoms, would provide a more comprehensive understanding of outcomes from interventions for MI.

Limitations
The focus of this scoping review was peer-reviewed literature within 11 electronic databases listing psychological and/or chaplaincy approaches to support adults who have experienced MI or been exposed to PMIEs. While credible psychological literature can be identified within such databases, chaplaincy and spiritual care literature within books and book chapters regarding intervention programs for MI/ PMIEs were not included. Therefore, this review did not consider the efficacy of any social or community intervention programs run and published by ecclesiastical or other religious organizations. Also, while some programs were noted within the peer-reviewed literature to be currently under the process of development or validation, these were not included in the current review given their ongoing development and evaluation.

Conclusion
This scoping review, based on a systematic search of the research literature, provides a comprehensive summary of current evidence for interventions to address MI outcomes and related symptoms. Unfortunately, most studies used symptoms of PTSD or depression as key outcome measures, pointing to the urgent need for a widely accepted, psychometrically sound measure of MI. More broadly, the quality and depth of research to date does not allow conclusions to be drawn about preferred approaches, much less of the relative benefits of psychological, chaplaincy, and combined psychological and chaplaincy approaches to addressing MI. The psychosocial and spiritual impacts of MI, suggest that a combined approach may be optimal; however, there is insufficient evidence to date to support such a conclusion. Future research should prioritize the development and testing of a multidisciplinary psychosocial spiritual model of care for MI.