Ayurvedic Dravya-Based Herbal Products for Cognition, Stress, Sleep, and Psychiatric Symptoms: A Node-Resolved Systematic Review and Meta-Analysis

Background: Ayurvedic dravya-based herbal products are increasingly studied for cognition, stress, sleep, and psychiatric symptoms, but synthesis is complicated by heterogeneous preparations, incomplete reporting of Rasapanchaka-relevant attributes, and ambiguous common-name labels. Objectives: To synthesize controlled human evidence on dravya-based herbal products for (A) cognition, (B) stress, sleep, and related well-being outcomes, and (C) psychiatric symptoms/disorders using a node-resolved framework. Methods: We conducted a PRISMA 2020-reported, node-resolved systematic review of controlled human studies evaluating a defined dravya node and at least one standardized mental-health instrument or cognitive test. PubMed/MEDLINE, the AYUSH Research Portal, and DHARA were searched from database inception to 4 January 2026; the evidence base was frozen on January 30, 2026, after deduplication, full-text retrieval, and manual reference-list screening. Interventions were mapped to node identifiers using botanical identity, part/material, and preparation; identity-uncertain labels were retained as separate strata. Results: Forty-nine controlled reports spanning 20 nodes were included. Evidence volume was concentrated in Bacopa monnieri (Brahmi) for cognition and Withania somnifera (Ashwagandha) for stress and sleep outcomes. Meta-analysis was feasible for three primary strata: W. somnifera (Ashwagandha) versus placebo on perceived stress and sleep quality, and curcumin versus placebo on depression severity. Reported adverse events were usually mild but inconsistently captured. Conclusions: Selected dravya nodes show potentially beneficial signals, but confidence in effect magnitude remains limited by heterogeneity, small-study effects, and reporting quality.