Childhood trauma and meaning in life in university freshmen: a chain mediation model and its experimental causal test

BACKGROUND: The formation of meaning in life is a pivotal developmental task during the transition to university, yet its potential undermining by early adverse experiences remains unclear. Building on meaning-making and developmental systems perspectives, this study examined a chain mediating model linking childhood trauma to two dimensions of meaning in life-presence of meaning (MLQ-P) and search (MLQ-S)-through psychological adaptation (PA) and emotion regulation (ER), and further explored its causal architecture using an experimental intervention. METHODS: Cross-sectional data were collected from 2,548 university freshmen across multiple Chinese universities. Participants completed the Childhood Trauma Questionnaire (CTQ), the Meaning in Life Questionnaire (MLQ), the Emotion Regulation Questionnaire (ERQ), and the Psychological Adaptation Subscale (CSPS-B-MH). After data-quality screening, we tested the chain mediating model separately for MLQ-P and MLQ-S using PROCESS Model 6 with 5,000 bias-corrected bootstrap resamples. In Study 2, 74 freshmen were randomly assigned to an adaptation-focused writing intervention or a neutral writing control condition. Pre- and post-test assessments measured psychological adaptation, emotion regulation, and meaning in life. The same analytic strategy was applied to test a chain mediation model. RESULTS: Study 1 revealed significant negative correlations between childhood trauma and all variables. For MLQ-P, the indirect effect via PA alone dominated (95.7% of total indirect effect), while the chain pathway (CT → PA → ER → MLQ-P) was significant but modest (2.1%). For MLQ-S, a different pattern emerged: the indirect effects via PA alone (56.8%), ER alone (22.1%), and the chain (21.3%) were more balanced. Study 2 showed that the intervention was associated with significant improvements in PA, ER, and total meaning in life. Mediation analysis indicated that the intervention's association with meaning in life was primarily transmitted through PA alone; the chain pathway was not significant. CONCLUSIONS: Study 1 revealed negative correlations between childhood trauma and all variables. For MLQ-P, childhood trauma was negatively associated with psychological adaptation (PA), PA positively with emotion regulation (ER), and ER positively with MLQ-P. The indirect effect via PA alone dominated (95.7% of total indirect effect), while the chain pathway (CT → PA → ER → MLQ-P) was significant but modest (2.1%). For MLQ-S, the indirect effect via PA alone was smaller (56.8%), while ER alone (22.1%) and the chain pathway (21.3%) played larger roles. Study 2 showed that the adaptation-focused writing intervention was associated with significant improvements in PA, ER, and total meaning in life. Mediation analysis indicated that the intervention's association with meaning in life was primarily transmitted through PA alone; the chain pathway was not significant.