Effect of religious and spiritual interventions on anxiety, depression, and stress: A systematic review and meta-analysis of randomized clinical trials

Abstract

This systematic review and meta-analysis aim to investigate the impact of religious and spiritual (R/S)-based interventions on mental health outcomes, specifically targeting depression, anxiety, and stress. The protocol was registered with the International Prospective Register of Systematic Reviews (PROSPERO), and the review followed Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Five major databases—PubMed, Web of Science, Scopus, the Cochrane Library, and Google Scholar—were searched for English-language randomized clinical trials (RCTs) from inception to September 2024. Study quality was assessed using the Cochrane Collaboration tool. Meta-analysis was conducted using odds ratios (OR) with 95% confidence intervals (CI). Seventy-four RCTs were included. R/S-based interventions significantly reduced depression (OR = 0.127, CI: 0.077–0.209; Z = 8.15; P < 0.001), anxiety (OR = 0.118, CI: 0.066–0.211; Z = 7.21; P < 0.001), and stress (OR = 0.019, CI: 0.005–0.082; Z = 5.34; P < 0.001). However, the review identified notable heterogeneity in study quality and intervention design. These findings support the integration of R/S interventions in mental health care, highlighting their potential to improve psychological outcomes. Nonetheless, significant methodological variability across studies calls for cautious interpretation. Standardized intervention protocols and culturally tailored research are necessary to enhance clinical applicability. Future studies should also explore gender-specific responses and long-term outcomes. Incorporating spiritual well-being into holistic care may enrich mental health interventions, especially in diverse cultural settings.

Introduction

Mental health disorders have emerged as prominent contributors to the global disease burden, exhibiting an alarming increase in their impact over the years.[1] The disability-adjusted life years due to mental disorders have significantly increased from 80.8 million in 1990 to 125.3 million in 2019, suggesting a growing mental health crisis.[2] The World Health Organization (2022) reported that one in every eight people globally suffers from mental disorders, with a high prevalence of mental health issues, particularly anxiety and depression, being observed during the COVID-19 pandemic.[3] The incidence of depression has been estimated to be 3.8% of the global population, with higher rates observed in adults and the elderly.[4,5] Anxiety disorders are similarly prevalent, affecting approximately 7.3% of individuals globally, with a 1-year prevalence of 11.6%.[6] Stress, closely related to anxiety and depression, has also been recognized as a significant mental health concern.[7,8]

The high prevalence of depression, anxiety, and stress disorders led to the need for effective treatments, and different approaches have been developed, including various psychological and pharmacological treatments.[9,10,11,12,13,14,15,16] Cultural differences and factors also contribute to mental health issues, especially depression and anxiety.[17,18,19] Accordingly, cultural factors have been considered in the development of mental health interventions.[20,21] Psychological interventions that focus on religious and spiritual dimensions or integrate these components into treatment can increase the effectiveness of therapeutic interventions in different cultures.[22] Based on this, various psychological therapies integrate religion and spirituality into therapeutic approaches, and the effectiveness of these types of interventions in improving mental health has been proven.[23,24,25] Interventions based on R/S have shown effectiveness in the treatment of several mental and physical health problems, especially in relation to substance use problems,[26] quality of life,[27] HIV outcomes,[28] consciousness,[29] cancer,[30] and kidney disease.[31]

With regard to the increasing interest in R/S-based interventions for mental health treatment, numerous studies have evaluated their effectiveness on depression, anxiety, and stress, leading to an increase in the number of systematic reviews and meta-analyses.[27,32,33,34,35,36,37,38,39] These studies generally confirm the efficacy of R/S interventions in mitigating mental health issues. However, a critical evaluation of such studies revealed several thematic and methodological gaps. Notably, the effectiveness of these interventions on stress remains understudied, and previous meta-analyses often exhibit a limited scope, focusing on specific types of interventions or including a limited number of studies. For instance, a recent meta-analysis by Marques et al. (2022) on religious and spiritual interventions for depression included only seven clinical trials, which revealed a significant gap in the literature.[35]

First, none of the meta-analytical studies have investigated the effectiveness of R/S interventions on stress. As mentioned above, the prevalence of stress is relatively high and alarming. Second, a meta-analysis on the effectiveness of religious-based interventions on depression and anxiety has been conducted. However, its scope is often limited to one type of R/S intervention, and the number of studies included in the meta-analysis is extremely limited, lacking comprehensive inclusion. For example, the most recent meta-analysis[35] on the effectiveness of R/S interventions in the treatment of depression includes only seven clinical trial studies. This was observed when the search conducted in this study showed that the number of qualified studies was much higher than in previous studies. Third, the effectiveness of various R/S interventions on depression, anxiety, and stress needs to be investigated because each of these interventions can show different effectiveness. Although one study[32] has already attempted to distinguish between these types of interventions, its analysis was mainly based on certain interventions with a limited number of studies in each subgroup, which include two studies. Moreover, previous meta-analyses had some methodological limitations that could affect the results, including the following: using the same dataset multiple times in the meta-analysis, defining worry instead of anxiety, combining dependent outcomes without methodological considerations, and combining randomized clinical trial studies and studies with a quasi-experimental design. Each of these considerations has extensive explanations and can affect the research outcomes.

Based on the current literature, it was hypothesized that R/S-based interventions significantly reduce the symptoms of depression, anxiety, and stress compared with control or standard treatments. This is based on the belief that R/S practices provide unique coping mechanisms that allow the patient to have a sense of purpose and foster community support, which are critical in mitigating the symptoms of several mental health disorders. Furthermore, this study hypothesizes that the impact of R/S-based interventions on depression, anxiety, and stress may differ across various time points after intervention. This hypothesis acknowledges that the benefits of such interventions might diminish over time, with either immediate or delayed effects on mental health outcomes. Hence, the aim of this study is to investigate the effectiveness of R/S-based interventions on depression, anxiety, and stress. The second objective of this study is to investigate the effect of R/S-based interventions on depression, anxiety, and stress using various scales. Finally, the third objective of this study is to investigate the effectiveness of R/S-based interventions on depression, anxiety, and stress at different time points.

Materials and Methods

Protocol and registration

The protocol for the study was registered in the International Prospective Register of Systematic Reviews (CRD42023409857). The present research protocol was conducted in accordance with the PRISMA guidelines.[40]

Inclusion criteria

The inclusion criteria for the eligible studies were as follows: (1) the study must be an RCT evaluating the effect of religious interventions on anxiety, depression, and stress; (2) the participants in these studies should be aged 18 years or older; (3) the studies must provide clear numerical data on baseline and postintervention measures of anxiety, depression, and stress levels; (4) the trials should include control groups receiving no intervention, placebo, or standard therapy; and (5) the studies should be published in peer-reviewed journals in English.

Exclusion criteria

The exclusion criteria aim to maintain the methodological integrity and relevance of the study. Nonexperimental designs such as observational, cross-sectional, case-control, and cohort studies, and reviews were excluded. Cluster-randomized trials were omitted due to uncorrectable clustering errors. Only peer-reviewed, published, English-language studies were included. Studies were excluded if they lacked sufficient numerical data, reported major comorbidities, had no control group in pre-post designs, reported only means without detailed outcomes, or duplicated datasets.

Information sources

To find studies related to this research, five databases were searched, including PubMed, Web of Science, Scopus, the Cochrane Library, and Google Scholar. All studies published in English since the formation of these databases until September 2024 were searched. The references of all previous studies that had the same topic as this research were also collected.

Search strategy

A set of keywords was used for the search strategy, and it was used in the form of a syntax for each database. The syntax for each of the databases, including PubMed, Web of Science, Scopus, and the Cochrane Library, is included in Supplementary Table 1.

Selection process

In the process of selecting eligible studies, duplicate studies were automatically identified using EndNote software version 8. In the following, two authors independently performed the selection process. The selection process was based on the eligibility criteria. After completing the selection process, any disagreement between the researchers was resolved through discussion.

Data collection process

The data extraction is based on data extracted from systematic reviews and meta-analyses that were previously published. After extracting the data, all the extracted data were re-examined and integrated.

Main outcomes and measures

The primary outcomes of this systematic review and meta-analysis were the effects of religion-based interventions on anxiety, depression, and stress among participants. All eligible studies were evaluated in terms of exposure variables, outcomes, intervention time points, and scales that were used to measure outcomes. The religious-based interventions were as follows: Islam-based interventions, spirituality education, religious cognitive behavioral therapy (RCBT), religious psychotherapy, the use of the holy Qur’an, pastoral services, prayers, mantram, meaning-centered interventions, Johri Healing, Spiritist “passe” intervention, spiritual healing, religious rational emotive behavior therapy, body–mind–spirit, spiritual counseling, Christian rational emotive therapy, short version life review, faith-based mind-body intervention, spiritual posts, and religious sociocultural psychotherapy. The evaluated outcomes, including depression, anxiety, and stress, were measured using different scales, including the Patient Health Questionnaire, General Health Questionnaire, Beck Depression Inventory, Beck Anxiety Inventory, Depression Anxiety Stress Scale, Hamilton Anxiety Rating Scale, Hamilton Depression Rating Scale, Spielberger State-Trait Inventory, Hospital Anxiety and Depression Scale, Perceived Stress Scale, Center for Epidemiological Studies Depression Scale, Clinician-Administered PTSD Scale, Brief Symptom Inventory, Geriatric Depression Scale, Edinburgh Postnatal Depression Scale, and other scales that were less used [Supplementary Tables 2 and 3].

Study risk of bias assessment

The quality of 75 included studies was assessed using the Cochrane Collaboration tool,[41] evaluating random sequence generation, allocation concealment, blinding, incomplete outcome data, selective reporting, and other potential biases [Supplementary Table 2]. Studies were categorized as low, unclear, or high risk of bias. While some, such as Bormann (2013) and Nasiri (2017), demonstrated low risk across most domains, many showed unclear risks, limiting confidence in their findings. A few, including Alagheband (2019) and Boelens (2009), exhibited high risk in certain domains, reducing reliability. Overall, the review highlights variable methodological rigor, underscoring the need for cautious interpretation and more robust trial designs in future research.

Data synthesis and statistical analysis

In this systematic review and meta-analysis, we evaluated the impact of R/S interventions on depression, anxiety, and stress. For each study, mean, standard deviation (SD), and sample size were extracted for intervention and reference groups; when SDs were not reported, they were derived from SEs or 95% CIs following the Cochrane Handbook.[42] Existing procedures were also used to pool dependent outcomes[43] using comprehensive meta-analysis software.[44] The ORs, calculated using the random-effects method, were presented with 95% CIs to provide a clear indication of the range of effects of the interventions.[45] The effect size used in this study was reported as an odds ratio and 95% CI.[46] Therefore, all the results obtained from the studies were converted and reported as an odds ratio. Our analysis aimed to evaluate the influence of religious-based interventions across various time points and use different scales for measuring mental health outcomes. The main objective of this study is to investigate the effect of religious-based interventions on depression, anxiety, and stress. Moreover, the analyses of the subgroups were examined based on time points and the scales used to measure the outcomes. Heterogeneity was assessed with the Q test and I² while publication bias was evaluated via funnel plots,[47,48] Egger’s test,[49,50] and the trim-and-fill method.[51] Moreover, sensitivity analysis was used to investigate the effects of outlier studies on the degree of heterogeneity. Sensitivity analyses examined the influence of outliers. All statistical procedures were performed using Comprehensive Meta-Analysis v3.[44]

Results

Study selection

The screening of studies for systematic review and meta-analysis was performed based on the PRISMA guidelines[40] in Figure 1. The initial search also yielded 12,463 studies [Figure 1]. During duplicate checking, 2,486 studies were removed. Subsequently, 9,524 studies were excluded based on the initial screening criteria. This led to the retrieval of 453 studies for a more detailed examination. Of these, 147 studies were selected for title and abstract screening. Finally, 74 RCTs were included in this study after full-text screening based on the inclusion and exclusion criteria.

Figure 1.

Flowchart diagram of studies. From: Page MJ, McKenzie JE, Bossuyt PM, Boutron I, Hoffmann TC, Mulrow CD, et al. The PRISMA 2020 statement: an updated guideline for reporting systematic reviews. BMJ 2021;372:n71. doi: 10.1136/bmj.n71

Characteristics of the included studies

This systematic review synthesized findings from 11,098 participants across a wide range of cultural contexts, with women’s representation varying from 0% to 50%. Research was conducted globally, spanning Asia, Europe, North America, South America, and Africa, reflecting cultural differences that shape the efficacy and reception of interventions.

Religious aspects were most frequently investigated in Muslim-majority settings such as Iran,[52,53,54,55,56,57] Malaysia,[58,59,60,61] Turkey,[62,63] Pakistan,[64] Japan,[65] and Tunisia,[66] while studies in the United States assessed interventions across multiple faiths.[67,68,69] Other studies were conducted in Australia,[60,70] India,[71] the Netherlands,[72] Romania,[73] and the United Kingdom.[74] The effectiveness of religious-based interventions on mental health was observed to vary significantly with sociodemographic factors, such as socioeconomic status, age, gender, marital status, and region. or instance, U.S. studies emphasized the role of spiritual therapy alongside psychotherapy, showing improvements in quality of life,[28,75] while Islamic practices integrated into interventions in Iran significantly reduced anxiety and depression.[76,77] Most studies included participants aged 20–40, though some focused on older adults.[78,79,80,81]

The interventions investigated included spiritual counseling based on the sound heart model in hemodialysis patients,[82] mantram meditation in veterans with posttraumatic stress disorder,[83] meaning-centered interventions in cardiovascular patients, patients with advanced cancer, and college students,[84,85,86] and behavioral activation of religious behaviors in depressed college students.[87] Other approaches included an integrative body–mind–spirit intervention for parents of children with eczema,[88] spiritual care and education for cardiac surgery patients, family caregivers, mothers of premature newborns, and women with preeclampsia,[89,90,91,92] internet-based contemplative prayer for Christians experiencing daily stress,[93] and a faith-based mind–body intervention for African American adults.[94] Studies also investigated Johrei healing in substance abuse recovery,[95] Spiritist “passe” interventions for anxiety,[96,97] internet-delivered spiritually integrated treatment for subclinical anxiety in the Jewish community,[98] and Christian versus secular or non-Christian rational-emotive therapy.[99,100]

Further studies evaluated a spiritually based intervention for adults with chronic illness^,[101] a multifaith spiritually based intervention for generalized anxiety disorder,[102] spiritual meditation compared with secular meditation and relaxation,[103,104] religious versus nonreligious cognitive behavioral therapy for depression in religious individuals,[105] and a spiritual intervention for postmenopausal depression.[106]

Effect of R/S-based interventions on depression

The effect of R/S-based interventions on depression was investigated in 56 studies. Evaluating the effect of religious-based interventions on depression showed that these interventions decreased depression. Based on this, the odds ratio of R/S-based interventions for depression was equal to 0.127 with a CI of 0.077–0.209 (Z = 8.15; P < 0.001; I² = 93.17).

Subgroup analysis

Figure 2 shows the impact of religious interventions on depression as measured by depression scales. The effect of the Beck Depression Inventory was equal to an odds ratio of 0.057 with a CI of 0.018–0.181 (Z = 4.83; P < 0.001; I² = 93.57; n = 18). The effect of the Depression Anxiety Stress Scale was equal to an odds ratio of 0.041 with a CI of 0.012–0.147 (Z = 4.92; P < 0.001; I² = 87.87; n = 6). The effect of the Hamilton Depression Scale was equal to an odds ratio of 0.182 with a CI of 0.059–0.560 (Z = 2.97; P = 0.003; I² = 88.64; n = 6). This effect of the Hamilton Depression Scale was equal to an odds ratio of 0.401 with a CI of 0.225–0.714 (Z = 3.10; P = 0.002; I² = 78.39; n = 11). Moreover, the effect of the other depression scales was nonsignificant.

Figure 2.

Forest plot of R/S-based interventions on depression in depression scales

Figure 3 shows the impact of R/S-based interventions on depression at various time points. This effect for 1 month was equal to an odds ratio of 0.093 with a CI of 0.025–0.338 (Z = 3.60; P < 0.001; I² = 95.31%; n = 11). This effect for 3 months was equal to an odds ratio of 0.270 with a CI of 0.077–0.944 (Z = 2.05; P = 0.040; I² = 94.33%; n = 9). This effect for 2 and 6 months was nonsignificant.

Figure 3.

Forest plot of R/S-based interventions on depression at different time points

Effect of R/S-based interventions on anxiety levels

The effect of R/S-based interventions on anxiety was investigated in 50 studies [Figure 4]. Evaluating the effect of R/S-based interventions on anxiety showed that these interventions decreased anxiety. Based on this, the odds ratio of R/S-based interventions for anxiety was equal to 0.118 with a CI of 0.066–0.211 (Z = 7.21; P < 0.001; I² = 94.33).

Figure 4.

Forest plot of R/S-based interventions on anxiety

Subgroup analysis

Figure 5 shows the impact of R/S-based interventions on anxiety or depression scales. The effect for the Beck Anxiety Inventory was equal to an odds ratio of 0.082 with a CI of 0.021–0.319 (Z = 3.60; P < 0.001; I² = 90.55; n = 9). The effect for the Depression Anxiety Stress Scale was equal to an odds ratio of 0.086 with a CI 0.038–0.198 (Z = 5.78; P < 0.001; I² = 74.46; n = 6). The effect of the Hamilton Anxiety Rating Scale was equal to an odds ratio of 0.051 with a CI of 0.010–0.272 (Z = 3.48; P < 0.002; I² = 94.86; n = 7). The effect for the Hospital Anxiety and Depression Scale was equal to an odds ratio of 0.243 with a CI of 0.119–0.499 (Z = 3.85; P < 0.001; I² = 86.04; n = 11). The effect of Spielberger State-Trait Inventory was equal to an odds ratio of 0.095 with a CI of 0.015–0.590 (Z = 2.52; P = 0.011; I² = 97.37; n = 12). Moreover, the effect on the General Health Questionnaire was nonsignificant.

Figure 5.

Forest plot of R/S-based interventions on anxiety in anxiety scales

Figure 6 shows the impact of R/S-based interventions on anxiety at various time points. This effect for 1 month was equal to an odds ratio of 0.238 with a CI of 0.097–0.585 (Z = 3.12; P = 0.002; I² = 88.34%; n = 9). The effect for 2 months was equal to an odds ratio of 0.343 with a CI of 0.143–0.826 (Z = 2.38; P = 0.017; I² = 63.03%; n = 4). The effect for 3 months was equal to an odds ratio of 0.374 with a CI of 0.205–0.681 (Z = 3.21; P = 0.001; I² = 77.86%; n = 9). The effect for 6 months was equal to an odds ratio of 0.169 with a CI of 0.035–0.801 (Z = 2.23; P = 0.025; I² = 86.48%; n = 5).

Figure 6.

Forest plot of R/S-based interventions on anxiety at different time points

Effect of R/S-based interventions on stress levels

The effect of religious-based interventions on stress was investigated in 15 studies. Evaluating the effect of R/S-based interventions on stress showed that these interventions reduce stress. Based on this, the odds ratio of R/S-based interventions on stress was equal to 0.019 with a CI of 0.005–0.082 (Z = 5.34; P < 0.001; I² = 96.93) [Figure 7].

Figure 7.

Forest plot of R/S-based interventions on stress

Figure 8 shows the impact of R/S-based interventions for stress on stress scales. The effect of the Depression Anxiety Stress Scale was equal to an odds ratio of 0.039 with a CI 0.007–0.227 (Z = 3.60; P < 0.001; I² = 92.30; n = 5). The effect of the Perceived Stress Scale was equal to an odds ratio of 0.034 with a CI 0.006–0.208 (Z = 3.66; P < 0.001; I² = 96.72; n = 8).

Figure 8.

Forest plot of R/S-based interventions on stress in stress scales

Figure 9 shows the impact of R/S-based interventions on stress at various time points. The effect of 1 month was equal to an odds ratio of 0.001 with a CI 0.00–0.063 (Z = 3.30; P = 0.001; I² = 98.45%; n = 4). The effect for 3 months was nonsignificant.

Figure 9.

Forest plot of R/S-based interventions on stress at different time points

Publication bias and heterogeneity

Evaluating the impact of R/S-based interventions on depression showed that the heterogeneity results were a Q test equal to 820.520 (df 56; P < 0.001) and I² equal to 93.17%, indicating a high heterogeneity.[107] The results of the publication bias investigation confirmed the presence of publication bias. For this purpose, the funnel plot was included in Figure 10. Egger’s test was conducted with a P value of < 0.001, and the trim-and-fill method[51] imputed 11 studies and adjusted the odds ratio of the impact of religious-based interventions on depression to 0.069 with a 95% CI of 0.039–0.122. This finding shows that after removing the publication bias, the effect of religious interventions on depression is still significant.

Figure 10.

Funnel plot of R/S-based interventions and depression

Evaluating the impact of R/S-based interventions on anxiety showed that the heterogeneity results were a Q test equal to 865.60 (df 49; P < 0.001) and I² equal to 94.33%, indicating a high heterogeneity.[107] The results of the publication bias investigation confirmed the presence of publication bias. For this purpose, the funnel plot was included in Figure 11. Egger’s test was conducted with a P value of < 0.001, and the trim-and-fill method[51] imputed 15 studies and adjusted the odds ratio of the impact of religious-based interventions on anxiety to 0.036 with a 95% CI of 0.018–0.074. This finding shows that after removing the publication bias, the effect of religious-based interventions on anxiety is still significant.

Figure 11.

Funnel plot of R/S-based interventions and anxiety

Evaluating the impact of religious-based interventions on stress showed that the heterogeneity results were a Q test equal to 456.32 (df 14; P < 0.001) and I² equal to 96.93%, indicating a high heterogeneity.[107] The results of the publication bias investigation confirmed the presence of publication bias. For this purpose, the funnel plot was included in Figure 12. Egger’s test was conducted with a P value of < 0.001, and the trim-and-fill method[51] imputed four studies and adjusted the odds ratio of the impact of R/S-based interventions on stress to 0.003, with a 95% CI of 0.000–0.030. This finding revealed that after removing the publication bias, the effect of religious-based interventions on stress is still significant.

Figure 12.

Funnel plot of R/S-based interventions and stress

Sensitivity analysis

A sensitivity analysis was also performed to evaluate the effects of outlier studies on the degree of heterogeneity. Based on this, outlier studies were excluded from the analysis compared with the remaining studies. Excluding the outlier, the studies did not affect the heterogeneity in the effects of R/S-based interventions on depression and anxiety. Moreover, we excluded five outlier studies that affected the heterogeneity in the effects of R/S-based interventions on stress, with an I² equal to 71.64.

Discussion

This study aimed to investigate the impact of R/S-based interventions on mental health, specifically focusing on depression, anxiety, and stress. Using a comprehensive systematic review and meta-analysis approach, this study included a diverse range of R/S-based interventions across various cultures. The meta-analysis, which pooled 58 studies on depression, revealed a significant reduction in depression rates due to R/S interventions. The results indicate the high efficacy of these interventions, revealing an 88% decrease in depression and confirming their high effectiveness. Even after adjusting for publication bias, this result was maintained and showed that the use of R/S interventions can be effective either in combination with other treatments or individually. The results obtained are consistent with previous review studies that examined the effectiveness of R/S interventions on mental health. However, certain limitations in the previous studies were considered, such as focusing on the type of R/S intervention, a specific population, or a type of mental disorder,[27,32,33,34,35] whereas in this research, the most comprehensive results with high methodological power were presented. This suggests that integrating R/S practices into therapeutic interventions could be beneficial, potentially owing to the pivotal role R/S plays in an individual’s life. R/S beliefs often imbue life events with meaning, contributing positively to mental well-being and breaking the vicious cycle of sadness characteristic of depression.[32,34]

Furthermore, this study investigated the effects of these interventions on anxiety and stress. Unlike previous reviews that primarily focused on depression, this meta-analysis uniquely addressed the impact on stress. Moreover, the findings corroborated the significant reduction in anxiety and stress due to these interventions, aligning with previous studies that highlighted the efficacy of R/S interventions in managing anxiety.[32,34]

In contextualizing the findings of this systematic review within the broader landscape of psychotherapy and spiritual care, a meaningful intersection between cognitive behavioral therapeutic modalities and R/S practices has been observed. This integration advocates for a holistic approach to mental health care that not only addresses psychological symptoms but also considers the spiritual well-being of patients.

The review’s findings are consistent with those of the existing literature on mental health, which presents a different perspective on the benefits and challenges of integrating R/S elements into therapy. The call for personalized treatments that reflect the patients’ R/S convictions, particularly in the context of chronic illnesses,[108] resonates with the patient-centered care model. This model focuses on the development of treatments based on individual values and beliefs, emphasizing the importance of incorporating spiritual and cultural dimensions into mental health care.

Nonetheless, the field encounters several challenges. The variability in the effectiveness of R/S-based interventions highlights the need for refined patient selection and intervention customization. As noted by Moritz (2006) and Razali (2002), incorporating cultural and R/S backgrounds requires greater cultural competence among practitioners. Similarly, Johnson (1992, 1994) demonstrated the potential universal applicability of Christian-based therapies but emphasized the necessity of a comprehensive framework for integrating R/S approaches across contexts.

The key strength of this review is its comprehensive scope, encompassing diverse interventions across cultures and conditions. The inclusion of numerous studies enhances generalizability, and the application of rigorous meta-analytic methods strengthens reliability. This study also addresses limitations noted in earlier works, providing one of the most extensive global assessments of R/S interventions on depression, anxiety, and stress.

However, limitations must be acknowledged. The Cochrane assessments revealed substantial variation in study quality, ranging from low to high risk of bias. Such disparities reduce confidence in the collective findings and necessitate cautious interpretation. High heterogeneity persisted despite subgroup and sensitivity analyses (45; 46). Publication bias, assessed through funnel plots (47; 48), Egger’s test (49; 50), and trim-and-fill (51), may still have influenced outcomes. Further, most studies originated from a limited number of countries, restricting cultural generalizability, while protocols for R/S-based interventions lacked uniformity. Gender-specific data were also insufficient,[109] preventing analysis of differential effects between men and women.

Despite these challenges, findings indicate that integrating R/S elements into mental health treatments can benefit patients whose beliefs form a core part of their identity. Future research should prioritize standardized protocols, consistent outcome measures, and inclusion of diverse populations. Studies exploring mechanisms of action and identifying individuals most likely to benefit are essential for developing more personalized approaches

In conclusion, while promising, R/S interventions require balanced, rigorous application, and continued investigation into the interplay between spirituality and mental health.

Conclusion

This systematic review and meta-analysis contribute to the growing evidence supporting the inclusion of R/S and spiritual interventions in mental health treatment. It also highlights the complexities of such integration. The diverse impacts observed across studies require cautious interpretation and a solid methodological approach in future research. Clinicians and researchers are urged to navigate these complexities and develop interventions that are evidence-based and culturally sensitive. Furthermore, this approach ensures that the spiritual dimensions of care are appropriately integrated, avoiding marginalization or misappropriation in the therapeutic process.

AI policy statement

The authors confirm that no generative artificial intelligence tools were used in writing or preparing this manuscript.

Ethical approval

Ethical approval was not required because this systematic review and meta-analysis used data from previously published studies.

Author’s contributions

SA conducted the statistical analysis. MABK contributed to the literature search, manuscript preparation, review, and supervision. AMA, MA and HA contributed to data collection and preparation of the original draft. All authors reviewed and approved the final manuscript.

Availability of data, code, and other materials

The data used in the meta-analysis were available in the imported articles.

Conflicts of interest

There are no conflicts of interest.

Funding Statement

This project was supported by SURE Plus Grant # 2982 from the United Arab Emirates University.