Participants and recruitment
The participants were 120 junior high school students from three classes at a public junior high school. The school’s principal, who had participated in a training workshop for the program in 2019, had requested that our research team implement the program in the principal’s school before the spread of COVID-19 started in Japan. However, during the first wave of the COVID-19 pandemic, the school was closed in accordance with the government’s request and reopened on May 7, 2020. The program was implemented in schools in June and July 2020. After the nationwide school closure, no closures were implemented in the participating school during the second (August 2020) and third waves (January 2021) of the pandemic in Japan. The study was conducted with the approval of the Institutional Review Board of the authors’ university (approval no. 201904). Written informed consent was obtained from school principals. Additionally, oral informed consent was obtained from all the students.
Intervention
The Up2-D2 (Ishikawa et al., 2019), a school-based universal prevention program for internalizing and externalizing problems in children, comprises 12 sessions based on cognitive-behavioral and positive psychological interventions: psychoeducation about emotion (session 1), behavioral activation (session 2), social skills training (sessions 3 and 4), relaxation (session 5), strength work (session 6), cognitive restructuring (sessions 7 and 8), exposure (sessions 9 and 10), problem-solving (session 11), and review and conclusion (session 12). Each session lasted 45 minutes and was conducted using the following procedures: a) introduction (i.e., reviewing the last session and explaining the goal and purpose of the session); b) learning target skills (i.e., cognitive-behavioral or positive psychological skills); c) practicing target skills (in both individual and group activities); and d) conclusion (i.e., explaining the homework and summarizing the session). Worksheets were distributed in each session to assist the children in learning the program components. Furthermore, to run the program in their classes, teachers were provided with teaching plans that included specific program procedures in school settings. Although the program was originally designed for elementary school students (grades 4-6), we conducted this study with junior high school students (grade 7).
Program Implementation (Training, supervision and follow-up procedure)
The participating teachers received two hours of teacher training before implementing the program, which included an overview of the program, the flow of each session, and how to run the program in class. During the implementation, the second author, who had also provided the teacher training, provided three rounds of one-hour supervision. The supervisor discussed the contents and intervention rationales of each session with the teachers and answered their questions about implementing the program in their classes. Finally, to improve the lasting effectiveness of the program, we distributed a handout describing the skills acquired in the program, which included specific examples of how the learned skills can be used in daily life. The teachers had the students use their skills in their classes, schools, and homes based on this information.
Measures
Assessments were carried out before, immediately after, two months, and six months after implementing the program using student-reported questionnaires. The questionnaires comprised the items of the five scales described below.
Strengths and Difficulties Questionnaire (SDQ)
The Japanese version of the SDQ is a self-report questionnaire that measures children’s emotional/behavioral difficulties and positive attitudes (Goodman, 2001; Noda, Ito, & Harada, 2013). It has five subscales: emotional symptoms, conduct problems, hyperactivity/inattention, peer relationship problems, and prosocial behavior. The total score indicates general difficulties for all subscales except prosocial behavior. The internal consistencies of the general difficulties of the SDQ-P for the whole sample were 0.77, 0.73, 0.77, and 0.70 at the pre-, post, two-month, and six-month assessments, respectively.
General Self-Efficacy Scale for Children-Revised (GSESC-R)
The GSESC-R is a self-report questionnaire for general self-efficacy in children (Fukui et al., 2009) with two subscales: sensitivity to failure and a positive attitude. The total GSESC-R score was used to assess general self-efficacy. Higher scores indicate higher self-efficacy. The internal consistencies of the total score of the GSESC-R for the whole sample were 0.86, 0.89, 0.90, and 0.88 at the pre, post, two-month, and six-month assessments, respectively.
Short version of the Spence Children’s Anxiety Scale (Short CAS)
The Short CAS is a self-report questionnaire that assesses anxiety symptoms in children and adolescents (Spence et al., 2014). The validity and reliability of the Japanese version of the Short CAS have been confirmed (Ishikawa et al., 2018). Higher scores indicated higher anxiety symptoms. The internal consistencies of the Short CAS for the whole sample were 0.87, 0.86, 0.88, and 0.90 at pre, post, two-month, and six-month assessments, respectively.
Depression Self-Rating Scale for Children (DSRS-C)
The DSRS-C (Birleson, 1981) is a self-report questionnaire that assesses depressive symptoms in children and adolescents. The reliability and validity of the Japanese version of the DSRS-C have been confirmed (Denda, Kako, Kitagawa, & Koyama, 2006). A short version of the DSRS-C developed by Namikawa et al. (2011) was used in this study. Higher scores indicated higher levels of depression. The internal consistencies of the DSRS-C for the whole sample were 0.77, 0.79, 0.82, and 0.79 at pre, post, two-month, and six-month assessments, respectively.
Anger Scale for Children and Adolescents (ASCA)
The ASCA is a self-report questionnaire for anger in children and adolescents (Takebe, Kishida, Sato, Takahash, & Sato, 2017). The reliability and validity of the ASCA have been examined (Takebe et al., 2017). Higher scores indicated higher levels of anger. The internal consistencies of the ASCA for the whole sample were 0.93, 0.95, 0.94, and 0.96 at the pre, post, two-month, and six-month assessments, respectively.
Statistical analysis
Analyses were conducted for all participant samples and separately for those with high anxiety. This study used mixed models of individuals and classes as variable effects, and time points (pre-assessment, post-assessment, two-month follow-up, and six-month follow-up) as fixed effects. We used the Bonferroni method for post hoc tests and Hedges’ g for effect sizes of 0.20, 0.50, and 0.80, which are considered small, medium, and large, respectively.