{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,8,10]],"date-time":"2026-08-10T13:30:25Z","timestamp":1786368625357,"version":"build-2736575974"},"reference-count":45,"publisher":"MDPI AG","issue":"8","license":[{"start":{"date-parts":[[2026,8,10]],"date-time":"2026-08-10T00:00:00Z","timestamp":1786320000000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100001691","name":"Japan Society for the Promotion of Science","doi-asserted-by":"publisher","award":["24KJ0093"],"award-info":[{"award-number":["24KJ0093"]}],"id":[{"id":"10.13039\/501100001691","id-type":"DOI","asserted-by":"publisher"}]},{"award":["24KJ0093"],"award-info":[{"award-number":["24KJ0093"]}],"id":[{"id":"https:\/\/ror.org\/00hhkn466","id-type":"ROR","asserted-by":"publisher"}]},{"name":"Moonshot Research and Development Program of the Japan Science and Technology Agency","award":["JPMJMS229C-14a"],"award-info":[{"award-number":["JPMJMS229C-14a"]}]},{"award":["JPMJMS229C-14a"],"award-info":[{"award-number":["JPMJMS229C-14a"]}],"id":[{"id":"https:\/\/ror.org\/00097mb19","id-type":"ROR","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Behav. Sci.","Behavioral Sciences"],"abstract":"<jats:p>As a crucial period for self and identity development, early adolescence may give rise to emotional issues due to inadequate methods of self-expression. Therefore, the development of self-expression during early adolescence may play a significant role in interpersonal relationships. \u201cAssertion\u201d refers to the ability to express one\u2019s thoughts and emotions appropriately while simultaneously respecting those of others; thus, assertiveness training (AT) focuses on appropriate expression while also respecting others. Previous studies have shown AT programs\u2019 effects over 1 to 6 months, but the minimum number of effective sessions has not been determined. Thus, this single-group study without a control group examined pre\u2013post changes in 102 5th-grade students following three 45 min AT sessions on self-expression, requesting favors, and politely declining requests. Changes in assertiveness and mental health were assessed using the TK-Style Communication Skills and the Strength and Difficulties Questionnaire (SDQ). Results of available case analyses (depending on the outcome) showed a significant increase in assertiveness scores and decreases in both nonassertiveness scores and SDQ total difficulties scores. Overall, three short AT sessions were associated with favorable pre\u2013post changes in assertiveness and mental health-related outcomes; however, the absence of a control group limits the causal interpretation.<\/jats:p>","DOI":"10.3390\/bs16081370","type":"journal-article","created":{"date-parts":[[2026,8,10]],"date-time":"2026-08-10T12:47:36Z","timestamp":1786366056000},"page":"1370","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":0,"title":["Effects of Three Assertion Training Sessions on Schoolchildren\u2019s Assertiveness and Mental Health"],"prefix":"10.3390","volume":"16","author":[{"ORCID":"https:\/\/orcid.org\/0000-0001-8805-2531","authenticated-orcid":false,"given":"Yuka","family":"Shiota","sequence":"first","affiliation":[{"name":"Japan Society for the Promotion of Science, Tokyo 102-0083, Japan"},{"name":"Department of Psychiatry and Neurobiology, Graduate School of Medical Science, Kanazawa University, Kanazawa 920-8640, Japan"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Naomi","family":"Fukushima","sequence":"additional","affiliation":[{"name":"United Graduate School of Child Development, Osaka University, Kanazawa University, Hamamatsu University School of Medicine, Chiba University, and University of Fukui, Kanazawa 920-8640, Japan"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Yuki","family":"Hasegawa","sequence":"additional","affiliation":[{"name":"Research Center for Child Mental Development, Kanazawa University, 13-1 Takara-machi, Kanazawa 920-8640, Japan"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Chiharu","family":"Tsuji","sequence":"additional","affiliation":[{"name":"United Graduate School of Child Development, Osaka University, Kanazawa University, Hamamatsu University School of Medicine, Chiba University, and University of Fukui, Kanazawa 920-8640, Japan"},{"name":"Research Center for Child Mental Development, Kanazawa University, 13-1 Takara-machi, Kanazawa 920-8640, Japan"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2026,8,10]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"309","DOI":"10.1111\/nuf.12430","article-title":"The effectiveness of assertiveness training program on psychological wellbeing and work engagement among novice psychiatric nurses","volume":"55","author":"Abdelaziz","year":"2020","journal-title":"Nursing Forum"},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"186","DOI":"10.1016\/j.pedn.2017.06.020","article-title":"The effectiveness of assertiveness training for school-aged children on bullying and assertiveness level","volume":"36","year":"2017","journal-title":"Journal of Pediatric Nursing"},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"2010","DOI":"10.1037\/dev0000245","article-title":"The quest for identity in adolescence: Heterogeneity in daily identity formation and psychosocial adjustment across 5 years","volume":"52","author":"Becht","year":"2016","journal-title":"Developmental Psychology"},{"key":"ref_4","first-page":"690","article-title":"The effect of assertiveness skills training on reduction of verbal victimization of high school students","volume":"3","author":"Boket","year":"2016","journal-title":"International Journal of Humanities and Cultural Studies"},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"127","DOI":"10.1123\/tsp.1.2.127","article-title":"A psychological skills educational program for closed-skill performance enhancement","volume":"1","author":"Boutcher","year":"1987","journal-title":"The Sport Psychologist"},{"key":"ref_6","first-page":"75","article-title":"Assessment of obesity, lifestyle, and reproductive health needs of female citizens of Al Ain, United Arab Emirates","volume":"22","author":"Carter","year":"2004","journal-title":"Journal of Health, Population and Nutrition"},{"key":"ref_7","unstructured":"Cohen, J. 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