A quasi-experimental controlled study of a school-based mental health programme to improve the self-esteem of primary school children

Children's mental health problems are significantly linked to low self-esteem, impacting various aspects of their lives and potentially leading to issues in adulthood. Existing self-esteem improvement programs have limitations, often lacking a strong theoretical basis or rigorous experimental designs. Harter's model suggests perceived competence and social support are crucial for self-esteem development. While some programs have incorporated Harter's theory, they often focus narrowly (e.g., eating disorders) and primarily target secondary school students. This study aimed to address these limitations by evaluating the Treasure File Programme (TFP), a school-based intervention designed for primary school children (ages 7-11) based on Harter's model. The TFP aimed to improve self-esteem by focusing on skill-building in personally important areas, incorporating ample social support, and providing positive self-evaluation activities. The study hypothesized that the TFP would improve self-esteem in primary school children and explored secondary effects on other self-concept domains.

The prevalence of anxiety and depressive disorders in children is substantial. Low self-esteem is a significant risk factor for mental health issues such as eating disorders, depression, and anxiety. Conversely, high self-esteem is associated with positive mental well-being and life outcomes. Previous self-esteem improvement programs have often lacked theoretical grounding or rigorous experimental evaluation. While some programs have utilized cognitive or social learning theories, they suffer from limitations like the lack of experimental studies or reliance on highly skilled therapists, hindering widespread implementation. Harter's theory highlights the roles of perceived competence in personally important areas and social support in shaping self-esteem. Existing programs based on this theory, while showing some success in preventing eating disorders, had limitations regarding age range, gender focus, and methodological rigor. The need for effective, theory-driven self-esteem interventions in primary school is crucial given the long-term consequences of low self-esteem. The unique cultural context of Japan, with its historical emphasis on collectivism potentially affecting self-esteem levels, also motivated the development and testing of the TFP.

This study employed a quasi-experimental design with intervention and control groups. Due to limitations in obtaining randomized consent from headteachers, schools were assigned to either the intervention or control group. The intervention group (n=794) received the TFP, while the control group (n=592) received the regular school curriculum. Participants were primary school students (grades 2-6) from nine public primary schools in Japan. The KINDL-R questionnaire, a validated multidimensional scale assessing self-esteem, physical well-being, emotional well-being, family relationships, friendships, and school performance, was administered at baseline and after the intervention. The TFP consisted of seven sessions, implemented by homeroom teachers, that involved activities such as goal setting, identifying strengths, creating a ‘Treasure File,’ exchanging positive messages with classmates and family, and self-reflection. Teachers received training and followed a standardized protocol to ensure consistency. Repeated measures ANCOVA and multilevel analyses were used to assess the impact of the TFP, controlling for potential confounding variables like grade, gender, school, and baseline scores. Students were divided into low, middle, and high self-esteem groups based on baseline scores for targeted analysis.

The TFP intervention demonstrated a significant improvement in self-esteem scores in the intervention group compared to the control group (p<0.001). Repeated measures ANCOVA, controlling for grade, gender, school, and baseline scores, showed that the TFP was effective for children with low (p=0.006) and middle (p=0.003) levels of self-esteem at baseline. However, no significant effects were observed in the high self-esteem group. Interestingly, both the intervention and control groups showed a decrease in self-esteem scores in the high self-esteem group from baseline to post-intervention, potentially suggesting a phenomenon related to self-esteem stability. Multilevel analysis also confirmed a significant effect of the TFP on self-esteem (p=0.006), although with a small effect size. No significant intervention effects were observed for physical well-being, emotional well-being, family relationships, friendships, or school performance. The intervention group showed an increase of 5.17 points in self-esteem post-intervention, while the control group showed a decrease of 0.32 points, signifying a significant difference in mean change between groups (p<0.001). The Cronbach’s alpha for the KINDL-R questionnaire was 0.772, indicating good internal consistency.

The findings support the hypothesis that the TFP is effective in improving self-esteem in primary school children with low and middle levels of self-esteem. The positive effects likely stem from the combination of social support provided through positive messages from peers, family, and teachers, and the skill-building approach which does not limit the areas children can focus on for skill development. The 'Treasure File' may also contribute to sustained impact by allowing children to revisit their goals, achievements, and positive feedback. The lack of effect on high self-esteem children might be explained by pre-existing high and unstable self-esteem potentially leading to decreased scores. The TFP, by fostering self-esteem through parental warmth and peer approval, may enhance self-esteem without inducing narcissism, but further research is needed to confirm this. While the effect size was small, the statistically significant improvement in self-esteem among low and middle self-esteem children is encouraging.

This study demonstrates the effectiveness of the TFP in enhancing self-esteem in primary school children with low and moderate self-esteem. The program’s success highlights the importance of combining skill-building, social support, and positive self-evaluation in self-esteem interventions. Future research should address limitations of the study by implementing a randomized controlled trial with a larger sample size and broader inclusion criteria. Exploring potential mediating and moderating factors, longitudinal follow-up assessments to assess lasting effects, and investigating the relationship between the TFP and narcissism will further illuminate its impact and potential.

The study's limitations include the non-randomized assignment of schools to groups, potential bias due to headteachers’ selection and knowledge of the program, inability to control for all confounding variables due to data privacy concerns, limited pre-post assessment, missing data, and potential bias from variations in teacher competence. The quasi-experimental design limits the ability to establish causal relationships conclusively. Future research should address these limitations through a rigorously designed randomized controlled trial with a more comprehensive assessment plan.