Regional disparities in insurance-covered cognitive behavioural therapy in Japan: a nationwide cross-sectional study using National Database Open Data, 2015–2023 - PMC Skip to main content An official website of the United States government Here's how you know Here's how you know Official websites use .gov A .gov website belongs to an official government organization in the United States. Secure .gov websites use HTTPS A lock ( Lock Locked padlock icon ) or https:// means you've safely connected to the .gov website. Share sensitive information only on official, secure websites. Search Log in Dashboard Publications Account settings Log out Search… Search NCBI Primary site navigation Search Logged in as: Dashboard Publications Account settings Log in Search PMC Full-Text Archive Search in PMC Journal List User Guide PERMALINK Copy As a library, NLM provides access to scientific literature. 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Learn more: PMC Disclaimer | PMC Copyright Notice BMJ Open . 2026 Apr 13;16(4):e115722. doi: 10.1136/bmjopen-2025-115722 Search in PMC Search in PubMed View in NLM Catalog Add to search Regional disparities in insurance-covered cognitive behavioural therapy in Japan: a nationwide cross-sectional study using National Database Open Data, 2015–2023 Takayuki Fujii Takayuki Fujii 1 Department of Nursing, Faculty of Nursing, Yasuda Women’s University, Hiroshima, Hiroshima Prefecture, Japan Find articles by Takayuki Fujii 1, ✉ , Yuji Nogami Yuji Nogami 2 Student Counseling Office, Nakamura Gakuen University, Fukuoka, Japan Find articles by Yuji Nogami 2 , Taiga Seo Taiga Seo 3 Akihabara Labor and Social Security Attorney Corporation, Tokyo, Japan Find articles by Taiga Seo 3 Author information Article notes Copyright and License information 1 Department of Nursing, Faculty of Nursing, Yasuda Women’s University, Hiroshima, Hiroshima Prefecture, Japan 2 Student Counseling Office, Nakamura Gakuen University, Fukuoka, Japan 3 Akihabara Labor and Social Security Attorney Corporation, Tokyo, Japan Supplemental material This content has been supplied by the author(s). It has not been vetted by BMJ Publishing Group Limited (BMJ) and may not have been peer-reviewed. Any opinions or recommendations discussed are solely those of the author(s) and are not endorsed by BMJ. BMJ disclaims all liability and responsibility arising from any reliance placed on the content. Where the content includes any translated material, BMJ does not warrant the accuracy and reliability of the translations (including but not limited to local regulations, clinical guidelines, terminology, drug names and drug dosages), and is not responsible for any error and/or omissions arising from translation and adaptation or otherwise. None declared. ✉ Takayuki Fujii; [email protected] Received 2025 Dec 21; Accepted 2026 Mar 31; Collection date 2026. Copyright © Author(s) (or their employer(s)) 2026. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ Group. This is an open access article distributed in accordance with the Creative Commons Attribution Non Commercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited, appropriate credit is given, any changes made indicated, and the use is non-commercial. See: https://creativecommons.org/licenses/by-nc/4.0/ . PMC Copyright notice PMCID: PMC13084977 PMID: 41974546 Abstract Abstract Objectives Cognitive behavioural therapy (CBT) is recommended as a first-line treatment for depression and anxiety disorders, but its utilisation under Japan’s national health insurance remains poorly understood. This study aimed to describe CBT utilisation patterns, quantify regional disparities across prefectures and analyse temporal trends from fiscal year (FY)2015 to FY2023. Design This was a nationwide repeated cross-sectional study. Setting Japan’s National Database of Health Insurance Claims and Specific Health Checkups Open Data (NDB Open Data), FY2015–2023. Participants All patients who received insurance-covered CBT in FY2023, with a longitudinal comparison across FY2015–2023. Primary and secondary outcome measures The primary outcomes were annual CBT claims and patient counts. The secondary outcomes included prefecture-level distribution, population-adjusted utilisation rates per 100 000 population, distribution by sex and age, monthly trends and temporal changes over 9 years. Regional variation in physician-delivered CBT was assessed using the coefficient of variation (CV) and extremal quotient (EQ). Results In FY2023, the total CBT claims numbered 38 045 with 8299 patients, representing only 0.14% of an estimated 6.03 million psychiatric patients. Physician-delivered CBT accounted for 99.6% (37 886 claims), whereas nurse-delivered CBT introduced in 2016 remained at 0.4% (159 claims). 13 of the 47 prefectures (27.7%) had zero or fewer than 10 claims. The population-adjusted physician-delivered CBT claims ranged from 370.96 per 100 000 in Okayama to 0.99 per 100 000 in Kumamoto, yielding an EQ of 375-fold. The CV among the 34 prefectures with measurable physician-delivered CBT was 174.8%. Despite indication expansions in 2016 and 2018, claims decreased by 9.9% from 42 216 in FY2015 to 38 045 in FY2023. Conclusions Insurance-covered CBT in Japan remains severely underused, with significant regional disparities. Incremental policy measures, including indication expansions and nurse-delivered CBT, have failed to improve access. Fundamental system reforms, potentially including dedicated psychological therapy services, are needed to ensure equitable access to evidence-based psychological treatments. Keywords: Health Services Accessibility, MENTAL HEALTH, Psychosocial Intervention, EPIDEMIOLOGY STRENGTHS AND LIMITATIONS OF THIS STUDY. This study provides a comprehensive nationwide analysis of cognitive behavioural therapy (CBT) utilisation across all 47 prefectures using NDB Open Data, which covers over 98% of Japan’s insured population. A longitudinal analysis spanning nine fiscal years (FY2015–2023) enabled the evaluation of policy changes, including indication expansions and the introduction of nurse-delivered CBT. This study adhered to the REporting of studies Conducted using Observational Routinely collected health Data (RECORD) guidelines and the Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) statement. National Database Open Data provides only aggregate statistics, precluding individual-level analyses of treatment outcomes, completion rates or diagnostic indications. Values below 10 are suppressed for privacy protection, introducing uncertainty in the data from the low-utilisation prefectures. Introduction Cognitive behavioural therapy (CBT) is the most extensively used evidence-based psychological treatment for depression and anxiety disorders. A comprehensive meta-analysis by Cuijpers and colleagues including 409 randomised controlled trials with 52 702 patients demonstrated that CBT is effective for depression, with an effect size of Hedges’ g=0.79 compared with control conditions and a number needed to treat of 3.8. 1 This effect size corresponds to a large treatment effect, and the NNT of 3.8 indicates that for approximately every four patients treated with CBT, one additional patient benefits compared with control conditions, confirming CBT as a highly effective intervention. The UK National Institute for Health and Care Excellence recommends CBT as first-line treatment for mild-to-moderate depression and various anxiety disorders. 2 In Japan, CBT for mood disorders was approved for insurance coverage in April 2010. The indication was subsequently expanded in April 2016 to include obsessive-compulsive disorder, social anxiety disorder, panic disorder and post-traumatic stress disorder (PTSD), with the concurrent introduction of nurse-delivered CBT under physician supervision. 3 Bulimia nervosa was added in 2018. The current reimbursement rates are 4800 yen (approximately US$32) per session for physician-delivered CBT and 3500 yen (approximately US$23) per session for nurse-delivered CBT. Despite these policy developments, evidence suggests that CBT remains severely underused in Japan. Hayashi et al analysed National Database (NDB) data from fiscal year (FY)2010 to FY2015 and reported that only 60 304 patients received CBT over 6 years, with a 424.7-fold disparity between prefectures. 4 Haraguchi et al subsequently demonstrated that the 2016 indication expansion did not increase CBT utilisation. 5 However, these studies were limited to data through FY2017 and could not evaluate the effects of the 2018 expansion or the long-term uptake of CBT delivered by nurses. This study aimed to (1) describe current CBT utilisation patterns using the latest available data (FY2023), (2) quantify prefecture-level regional disparities with population-adjusted rates and (3) analyse temporal trends from FY2015 to FY2023 to evaluate the impact of policy changes on CBT accessibility. Methods Study design This nationwide repeated cross-sectional study used publicly available aggregate annual data from the NDB Open Data. This report adheres to the REporting of studies Conducted using Observational Routinely collected health Data (RECORD) guidelines 6 and the Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) statement 7 ( online supplemental material 1 : RECORD Checklist). Data source The NDB is a comprehensive nationwide claims database established by the Japanese Ministry of Health, Labour and Welfare (MHLW) in 2009. The NDB contains virtually all insurance claims submitted under Japan’s universal health insurance system, covering over 98% of the population. 8 NDB Open Data are aggregate, anonymised statistics extracted from this database, providing procedure-level claims and patient counts stratified by prefecture, sex, 5-year age groups and month of service. To protect patient privacy, values based on fewer than 10 cases are suppressed (displayed as ‘--’) in the published data. We used NDB Open Data releases 1 through 10, covering FY2014 through FY2023 (each FY runs from April to March). As CBT was approved for insurance in FY2010 and the first NDB Open Data release covered FY2014, our longitudinal analysis spanned FY2015 (release 2) to FY2023 (release 10). Data were downloaded from the MHLW website in May 2025. 9 Study variables The primary outcomes were annual CBT claims and patient counts. CBT was identified using procedure codes from the medical fee schedule category ‘I. Psychiatric Specialty Therapies’, specifically I003-2 (cognitive therapy/CBT): FY2018 onwards 180056410: Physician-delivered CBT (480 points per session). 180047810: Nurse-delivered CBT under physician supervision (350 points per session). FY2015–2017 (legacy codes) 180033210: CBT (standard, 420 points). 180035910: CBT by designated mental health physician in psychiatric emergency settings (500 points). 180047810: Nurse-delivered CBT (350 points, from FY2016). Secondary outcomes included distribution by prefecture (n=47), sex (male, female), age group (19 5-year bands from 0 to 4 to ≥90 years) and month (April to March). Statistical analysis We calculated the descriptive statistics for claims and patient counts at the national and prefecture levels. Population-adjusted utilisation rates per 100 000 population were calculated using October population estimates from the Statistics Bureau of Japan for each corresponding FY. 10 Regional variation was quantified using established methods for small-area variation analysis: 11 coefficient of variation (CV=SD/mean×100%), calculated excluding prefectures with zero or suppressed values and extremal quotient (EQ=maximum/minimum among non-zero values). The CV quantifies the magnitude of variation relative to the national average, with a value of zero indicating no variation and values exceeding 100% indicating extremely uneven distribution. The EQ measures the gap between the highest-utilisation and lowest-utilisation regions; values close to 1 indicate equality, whereas larger values indicate greater disparity. These metrics were applied to prefecture-level population-adjusted claims rates for physician-delivered CBT, which accounted for over 99% of all CBT claims. The mean number of sessions per patient was calculated as total claims divided by total patients. Monthly variation was assessed using the CV of monthly claim counts. Temporal trends were analysed as year-on-year percentage changes in total claims from FY2015 to FY2023. Values below 10 are suppressed in the NDB Open Data (displayed as ‘–’) for privacy protection. Prefectures with suppressed values were excluded from the CV calculations. All analyses were performed using IBM SPSS Statistics V.28 (IBM, Armonk, New York, USA) and verified using R V.4.5.2 (R Foundation for Statistical Computing, Vienna, Austria; packages: readxl, dplyr). Results were concordant across both platforms. Patient and public involvement Patients and the public were not involved in the design, conduct or reporting of this study. The results will be disseminated through the MHLW and relevant academic societies. Results Overall utilisation in FY2023 In FY2023, the total annual CBT claims (each representing one session billed to insurance) in Japan numbered 38 045, with 8299 patients ( table 1 ). Physician-delivered CBT accounted for the vast majority, with 37 886 claims (99.6%) and 8260 patients (99.5%). Nurse-delivered CBT remained minimal, with 159 claims (0.4%) and 39 patients (0.5%). Table 1. Summary of insurance-covered CBT utilisation in Japan, FY2023. Variable Claims (n) Patients (n) Percentage (%) Physician-delivered CBT 37 886 8260 99.6 Nurse-delivered CBT 159 39 0.4 Total 38 045 8299 100.0 Open in a new tab CBT, cognitive behavioural therapy; FY, fiscal year. Regional variation metrics Prefectures with 0 claims: 9 (19.1%). Prefectures with <10 claims (suppressed): 4 (8.5%). Total with no/negligible CBT: 13 (27.7%). EQ: 375-fold (Okayama vs Kumamoto). CV: 174.8%. Data source: 10th NDB Open Data (FY2023), MHLW, Japan. The mean number of CBT sessions per patient was 4.6 (37 886/8260 patients). This is substantially below the standard protocol of 16–20 weekly sessions that are typically recommended for CBT. Because NDB Open Data provides only aggregate totals rather than individual-level data, the median and IQR of sessions per patient could not be calculated, nor could temporal trends in session counts per patient be examined. Based on the 2023 Patient Survey estimate of 6.03 million patients with psychiatric disorders, 12 only approximately 0.14% received insurance-covered CBT. This estimate should be interpreted with caution, as the denominator includes all patients with psychiatric disorders, whereas insurance-covered CBT in Japan is currently reimbursed only for specific indications (mood disorders, obsessive-compulsive disorder, social anxiety disorder, panic disorder, PTSD and bulimia nervosa). The proportion among patients with these specific diagnoses would be higher, but diagnosis-specific patient counts were not available from the Patient Survey for this calculation. Regional disparities Marked geographical disparities were observed ( table 1 ; figure 1 ; online supplemental table 1 ). 9 of the 47 prefectures (19.1%) had zero CBT claims: Aomori, Akita, Niigata, Fukui, Yamaguchi, Tokushima, Kochi, Nagasaki and Oita. An additional four prefectures (8.5%) had fewer than 10 claims (suppressed): Yamagata, Kagawa, Saga and Okinawa. Thus, 13 prefectures (27.7%) had no or negligible CBT provisions. The four suppressed prefectures could each contain between 1 and 9 physician-delivered CBT claims, representing a total possible range of 4–36 additional claims. This represents less than 0.1% of the national total of 37 886 physician-delivered claims, indicating that cell suppression had a negligible impact on the overall results. Figure 1. Geographical distribution of physician-delivered CBT claims per 100 000 population across 47 prefectures, FY2023. ( A ) Choropleth map showing CBT utilisation rates. Darker shading indicates higher utilisation. Nine prefectures (white) had 0 claims, and four prefectures (grey) had fewer than 10 claims (suppressed for privacy). ( B ) Bar chart showing 34 prefectures with measurable CBT claims, ranked by utilisation rate. The dashed line indicates the national average (30.3 per 100 000). CBT, cognitive behavioural therapy; FY, fiscal year. Open in a new tab The top five prefectures by claims were Aichi (9780; 25.8%), Okayama (6937; 18.3%), Tokyo (4080; 10.8%), Osaka (2100; 5.5%) and Miyazaki (1927; 5.1%). These five prefectures accounted for 65.5% of all physician-delivered CBT claims. Population-adjusted physician-delivered CBT claims per 100 000 population ranged from 370.96 in Okayama to 0.99 in Kumamoto, yielding an EQ of 375-fold. The national average was 30.3 per 100 000 population. Among the 34 prefectures with non-zero, non-suppressed claims, the CV was 174.8%, indicating an extremely high variability. Nurse-delivered CBT was implemented in only five prefectures: Shiga (83 claims), Wakayama (50), Yamagata (20), Tokyo (<10) and Kagoshima (<10). Sex and age distribution Among physician-delivered CBT claims, females accounted for 64.7% (24 490 of 37 869 claims) and males for 35.3% (13 379), yielding a female-to-male ratio of 1.83:1 ( table 2 ). Table 2. Distribution of physician-delivered CBT claims by sex and age group, FY2023. Age group Male (n) Female (n) Total (n) Male (%) Female (%) 0–19 years 2011 2375 4386 45.9 54.1 20–49 years 8354 16 188 24 542 34.0 66.0 50–59 years 1918 3503 5421 35.4 64.6 ≥60 years 1096 2424 3520 31.1 68.9 Total 13 379 24 490 37 869 35.3 64.7 Open in a new tab Note: Female-to-male ratio=1.83:1. Peak age groups: 25–29 years (12.2%) and 40–44 years (11.2%). The 0–4 age group (17 claims) is excluded due to suppression; totals therefore sum to 37 869 rather than 37 886. CBT, cognitive behavioural therapy; FY, fiscal year. The age distribution was concentrated among working-age adults only. Those aged 20–49 years accounted for 64.8% of all claims, with peaks at ages 25–29 (12.2%) and 40–44 (11.2%) years. Children and adolescents (0–19 years) represented 11.6% of the total, whereas older adults (≥60 years) accounted for 9.3% ( online supplemental table 2 ). Monthly trends Monthly claims were relatively stable throughout the year, with the highest number in October (3470) and the lowest in January (2759). The monthly CV was 6.5%, indicating minimal seasonal variation. Longitudinal trends FY2015–2023 An analysis of nine fiscal years revealed no sustained increase in CBT utilisation despite policy expansions ( table 3 ; online supplemental figure 1 ). Claims initially rose from 42 216 in FY2015 to 44 660 in FY2016 (+5.8%), coinciding with the indication expansion and introduction of nurse-delivered CBT. However, claims subsequently declined, reaching a nadir of 35 231 in FY2022 before recovering slightly to 38 045 in FY2023. Overall, claims decreased by 9.9% between FY2015 and FY2023. Table 3. Temporal trends in CBT claims, FY2015–2023. Fiscal year Total claims Physician CBT Nurse CBT Change (%) FY2015 42 216 42 216 — — FY2016 44 660 44 660 <10 +5.8 FY2017 43 422 43 422 <10 −2.8 FY2018 38 923 38 897 26 −10.4 FY2019 37 384 37 257 127 −4.0 FY2020 35 470 35 236 234 −5.1 FY2021 37 562 37 272 290 +5.9 FY2022 35 231 34 992 239 −6.2 FY2023 38 045 37 886 159 +8.0 Open in a new tab CBT, cognitive behavioural therapy; FY, fiscal year. Key findings Overall change FY2015–FY2023: −9.9%. 2016 indication expansion: +5.8% (followed by decline in subsequent years). Nurse CBT peak: 290 claims in FY2021 (0.77% of total). Nurse CBT in FY2023: 159 claims (0.42% of total). Note: ‘<10’ indicates values suppressed for privacy protection. ‘—’ indicates not applicable. For FY2016–2017, physician CBT and total values appear identical because the exact nurse CBT component (<10 claims) could not be separated from the reported total. Nurse-delivered CBT has failed to achieve meaningful uptake. After the introduction in FY2016, claims remained below 10 (suppressed) in FY2017, rose gradually to a peak of 290 (0.77% of total) in FY2021 and then declined to 159 (0.42%) in FY2023. After 8 years, nurse-delivered CBT represented less than 0.5% of all CBT claims. Discussion Principal findings This study provides the first comprehensive analysis of CBT utilisation in Japan using NDB Open Data through FY2023, with longitudinal trends over 9 years of data. Four principal findings were obtained. First, CBT utilisation remains extremely low in the country. Only 8299 patients received insurance-covered CBT in FY2023, representing approximately 0.14% of the estimated 6.03 million psychiatric patients in Japan (noting that this denominator includes all psychiatric diagnoses, not only those eligible for insurance-covered CBT; the proportion among eligible diagnoses would be higher). For context, England’s NHS Talking Therapies programme provided services to 1.26 million people in 2023/2024, with 671 648 completing a course of treatment. 13 Adjusting for population differences (England: 56.8 million; Japan: 125.7 million), England’s per capita access rate is approximately 2220 per 100 000 compared with 6.6 per 100 000 in Japan, a roughly 340-fold difference. Second, regional disparities are extreme. Over one-quarter (27.7%) of the prefectures had zero or negligible CBT provision. The EQ of 375-fold substantially exceeds typical geographical variation in healthcare utilisation. 11 Although slightly improved from the 424.7-fold disparity reported by Hayashi et al for FY2010–2015, 4 the variation remains extraordinary. Third, nurse-delivered CBT has not been meaningfully addressed. Despite being introduced 8 years ago, it accounts for only 0.4% of claims and is available in only 5 of the 47 prefectures. Fourth, indication expansions have not increased the utilisation. Claims decreased by 9.9% from FY2015 to FY2023, despite expansions in 2016 and 2018. This confirms and extends the findings of Haraguchi and colleagues through FY2017. 5 Comparison with previous studies Our findings are consistent with prior research documenting CBT underutilisation in Japan. Hayashi et al reported annual patient counts of approximately 10 000 during FY2010–2015. 4 Our finding of 8260 physician-delivered CBT patients in FY2023 suggests no improvement over the subsequent 8 years. A survey by Takahashi et al found that only 37.9% of responding Japanese psychiatric clinics provided CBT (6.2% of all clinics nationwide), citing lack of time (38.8%), inadequate profitability (32.9%) and insufficiently trained staff (28.2%) as primary barriers. 14 These structural barriers likely explain the concentration of CBT provision in a small number of prefectures. Policy implications Our findings suggest that incremental policy adjustments are insufficient to improve CBT access in Japan. More fundamental reforms may be required in the future. Dedicated psychological therapy services: The UK’s Improving Access to Psychological Therapies (IAPT) (now NHS Talking Therapies) programme established standalone services with dedicated funding, systematic workforce training and self-referral pathways. Workforce expansion: Extending reimbursement eligibility to clinical and certified public psychologists could substantially expand the capacity. Reimbursement reform: Current CBT reimbursement may be insufficient to incentivise provision, given the intensive training and session time required. Digital CBT: Internet-delivered CBT with therapist support has demonstrated efficacy comparable to face-to-face CBT 15 and could help address geographical access barriers to care. Strengths and limitations This study had several strengths. The NDB Open Data provides near-complete population coverage. The analysis of all 47 prefectures with population-adjusted rates enabled meaningful geographical comparisons. The 9-year longitudinal perspective allows for the evaluation of policy changes. Adherence to the RECORD guidelines ensures transparent reporting. However, this study has some limitations. First, the NDB Open Data only provides aggregate counts, precluding the analysis of treatment outcomes or completion rates. Second, the suppression of values below 10 introduces uncertainty in low-utilisation prefectures. However, this impact is relatively minor: the four prefectures with suppressed physician-delivered CBT data could contribute at most 36 additional claims (4–36 range), representing less than 0.1% of the national total. Cell suppression had minimal influence on the CV calculation because these prefectures were excluded, and its effect on the EQ was negligible because the minimum non-suppressed value (Kumamoto, 0.99 per 100 000) is already extremely low. Third, the diagnostic indications cannot be distinguished. Fourth, CBT provided outside insurance coverage was not captured. Fifth, this study cannot directly identify the causes of regional variation. Conclusions Insurance-covered CBT in Japan remains severely underused 14 years after its approval, with only 0.14% of psychiatric patients receiving treatment and extreme geographical disparities. Policy measures, including indication expansions and nurse-delivered CBT, have failed to improve access. Fundamental system reforms may be necessary to ensure equitable access to evidence-based psychological treatments. Supplementary material online supplemental table 1 bmjopen-16-4-s001.xlsx (9.2KB, xlsx) DOI: 10.1136/bmjopen-2025-115722 online supplemental table 2 bmjopen-16-4-s002.xlsx (6.6KB, xlsx) DOI: 10.1136/bmjopen-2025-115722 online supplemental figure 1 bmjopen-16-4-s003.tiff (696.3KB, tiff) DOI: 10.1136/bmjopen-2025-115722 online supplemental file 1 bmjopen-16-4-s004.docx (12.6KB, docx) DOI: 10.1136/bmjopen-2025-115722 Acknowledgements We thank the Ministry of Health, Labour and Welfare for making the NDB Open Data publicly available. Footnotes Funding: The authors have not declared a specific grant for this research from any funding agency in the public, commercial or not-for-profit sectors. Prepublication history and additional supplemental material for this paper are available online. To view these files, please visit the journal online ( https://doi.org/10.1136/bmjopen-2025-115722 ). Provenance and peer review: Not commissioned; externally peer reviewed. Patient consent for publication: Not applicable. Data availability free text: Data are available in a public, open access repository. The NDB Open Data used in this study are publicly available from the Ministry of Health, Labour and Welfare website ( https://www.mhlw.go.jp/stf/seisakunitsuite/bunya/0000177182.html ). Population estimates are available from the Statistics Bureau of Japan ( https://www.stat.go.jp/data/jinsui/ ). All data relevant to the study are also included in the article and supplementary materials. Patient and public involvement: Patients and/or the public were not involved in the design, or conduct, or reporting, or dissemination plans of this research. Ethics approval: This study used only publicly available aggregate data that contained no personally identifiable information. According to Japan’s Ethical Guidelines for Medical and Biological Research Involving Human Subjects (2021), research using only publicly available information is exempted from ethics committee review. Data availability statement Data are available in a public, open access repository. All data relevant to the study are included in the article or uploaded as supplementary information. References 1. Cuijpers P, Miguel C, Harrer M, et al. Cognitive behavior therapy vs. control conditions, other psychotherapies, pharmacotherapies and combined treatment for depression: a comprehensive meta-analysis including 409 trials with 52,702 patients. World Psychiatry. 2023;22:105–15. doi: 10.1002/wps.21069. [ DOI ] [ PMC free article ] [ PubMed ] [ Google Scholar ] 2. National Institute for Health and Care Excellence . London: NICE; 2022. Depression in adults: treatment and management, nice guideline [ng222] https://www.nice.org.uk/guidance/ng222 Available. [ PubMed ] [ Google Scholar ] 3. 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Supplementary Materials online supplemental table 1 bmjopen-16-4-s001.xlsx (9.2KB, xlsx) DOI: 10.1136/bmjopen-2025-115722 online supplemental table 2 bmjopen-16-4-s002.xlsx (6.6KB, xlsx) DOI: 10.1136/bmjopen-2025-115722 online supplemental figure 1 bmjopen-16-4-s003.tiff (696.3KB, tiff) DOI: 10.1136/bmjopen-2025-115722 online supplemental file 1 bmjopen-16-4-s004.docx (12.6KB, docx) DOI: 10.1136/bmjopen-2025-115722 Data Availability Statement Data are available in a public, open access repository. All data relevant to the study are included in the article or uploaded as supplementary information. 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