Mapping the Mental Health Funnel: Unlocking the Hidden Power of DASS-21 for Suicidal Ideation Screening Through Structural Equation Modelling

Abstract

Background: The rising prevalence of mental health morbidity among medical students necessitates a move from reactive crisis management to proactive population screening. This study aimed to map the "Mental Health Funnel" the epidemiological progression from generalized distress to suicidal ideation (SI) to identify the optimal window for institutional intervention. Methods: A cross-sectional community-based survey was conducted among 420 medical students. We employed a dual-stage analytical approach to bridge descriptive prevalence with structural causality. First, a Multiple Response Funnel was constructed to visualize the transition of risk. Second, Structural Equation Modelling (SEM) was used to identify the primary mediators of suicidal risk, applying robust estimation to ensure findings remained stable across the population distribution. Results: The study identified a clear cascading risk profile. Epidemiological mapping via the "Risk Funnel" showed that while 41% and 25% of the students reported anxiety and stress, 58% of these cases were comorbid. This distress "funnelled" into clinical depression (78% of comorbid cases), with 42% of the depressed cohort manifesting suicidal ideation. The structural analysis confirmed these findings, demonstrating that depression acts as a critical gateway (β = 0.87). Statistical fit indices confirmed the model was highly representative of the student population (CFI = 0.991, RMSEA = 0.036). Conclusion: Suicidal ideation in medical students is not an isolated event but the final stage of a predictable cascading pathway. These findings justify a Primary Prevention strategy: by screening for comorbid stress and anxiety using the DASS-21, institutions can interrupt the funnel before students’ progress into clinical depression and high-risk suicidal behaviour.