This study investigates the complex relationship between mental well-being and academic productivity among postgraduate students at an Indian university, contextualized within an escalating national mental health crisis in higher education. Amidst intense academic pressure and unique sociocultural stressors, understanding the psychological landscape of advanced-degree candidates is critical for institutional and national policy. This research employed a quantitative, cross-sectional design, surveying 150 postgraduate, and Ph.D. students across Science, Arts, and Commerce disciplines. Mental well-being was assessed using a suite of standardized instruments, including the Depression, Anxiety, and Stress Scale (DASS-21), while academic productivity was measured via custom metrics of motivation, focus, and satisfaction. Statistical analyses, including correlation, Chi-Square tests, and Multivariate Analysis of Variance (MANOVA), were conducted to explore these dynamics. The findings reveal a high prevalence of psychological distress within the sample and a significant, strong negative correlation between indicators of stress, anxiety, and depression, and measures of academic motivation and satisfaction. A pivotal finding emerged from the MANOVA, which indicated statistically significant differences in mental health profiles across academic disciplines. Post-hoc analyses identified students in the Science stream as a particularly vulnerable group, reporting significantly higher levels of anxiety and hopelessness compared to their peers in Arts and Commerce. These results underscore the inadequacy of a regular approach to student mental health. The study concludes with evidence-based recommendations for developing tailored, field-specific mental health interventions, enhancing institutional support systems, and integrating campus services with national mental health initiatives to foster a more resilient and productive academic community.