Maternal education and adolescent psychological symptom severity: the synergistic reversal trade-offs between perceived maternal support and parental educational expectations.

Adolescence is a critical developmental stage characterized by a high incidence of psychological and behavioral problems (). Research indicates that approximately 50% of lifetime mental illnesses have their onset by age 14 (), and mental health during this period exerts a profound influence on an individual’s lifelong development (). Currently, the mental health status of adolescents in China presents a concerning picture. It is estimated that about 25% of Chinese adolescents exhibit mild to severe depressive symptoms, and over 30 million individuals under the age of 17 are affected by emotional or behavioral disorders ().This severe situation necessitates urgent attention and effective intervention from all sectors of society. In response to this adolescent mental health crisis, China has initiated a systematic policy-level response. The “People’s Republic of China Family Education Promotion Law” () explicitly designates the family as the “primary responsible entity” for mental health education, emphasizing the pivotal role of parents as “first teachers”. This legislative orientation aligns with ecological systems theory (), which underscores the family’s central role in adolescent development. Empirical research, such as that by Reiss, demonstrates that parental education is a key determinant of adolescent mental health (). Parental education level not only reflects a family’s cultural and educational resources but also signifies its capacity to translate health awareness into concrete practices (). Within the Chinese familial context, mothers often assume the role of “significant others” in adolescent socialization due to traditional gender-based divisions of labor (, ). Consequently, maternal education emerges as a particularly critical focal point for efforts aimed at promoting adolescent mental health. Regarding the relationship between maternal education and adolescent mental health, existing research shows significant divergence in perspectives. Some scholars argue that mothers with higher education levels promote adolescent mental health by optimizing parent-child interactions and adopting evidence-based parenting styles (e.g., higher expectations but less harshness) (–). In contrast, other studies suggest that mothers with higher education levels may exert greater academic pressure (), thereby increasing mental health risks for adolescents. Additionally, from the perspective of ecological systems theory, as adolescents age and other environments (such as peers and schools) become more influential, the impact of parental education may diminish (). Some studies propose that in specific contexts (e.g., Asian regions or low- and middle-income countries), there is no significant association between the two (). These discrepancies in findings can be attributed to two main research limitations: First, most existing studies are based on linear assumptions, overlooking the possibility of nonlinear relationships. For example, the protective effect of maternal education on mental health may be stronger in younger years and weaken over time, indicating a developmental nonlinearity (). Second, existing mechanism research is fragmented and fails to adequately incorporate the interactions between distal resources (e.g., maternal education) and proximal processes (e.g., parental support and educational expectations) proposed by ecological systems theory (, ), making it difficult to comprehensively explain how distal resources influence adolescent mental health through proximal processes.Therefore, this study aims to address two key questions: Does maternal education level have a nonlinear impact on adolescent mental health? If so, what are the mechanisms?