Effect of yoga Nidra (yogic sleep) in sleep disturbances and insomnia: systematic review and metanalysis.

purposeInsomnia and sleep disturbances are increasing globally. Yoga Nidra (YN), a guided deep relaxation with stress and anxiety reducing effects, has emerged as a potential therapy for improving sleep quality. This systematic review and meta-analysis aims to evaluate its effectiveness in managing sleep disturbances and insomnia.

methodsThis review was registered with PROSPERO (CRD420251114346). A systematic search of four databases identified randomized controlled trials (RCTs) and observational studies in English up to March 2025. Eligible studies enrolled adults (≥ 18 years) with poor sleep quality (Pittsburgh Sleep Quality Index [PSQI] ≥ 5) or insomnia ( Insomnia Severity Index [ISI] ≥ 8). Interventions involved YN as a standalone or adjunct therapy. The primary outcome was subjective sleep quality (PSQI, ISI), while secondary outcomes included objective parameters assessed through polysomnography, actigraphy, or sleep diaries. Two reviewers independently extracted data and assessed study quality using RoB 2 and ROBINS-I tool and certainty of evidence using GRADE methodology. Meta-analyses were performed for outcomes reported in at least two studies.

resultsThree separate metanalyses were conducted: two randomized controlled trials (RCTs) assessing PSQI, two observational studies evaluating PSQI, and two RCTs examining ISI. Notably, one study was common to both RCT analyses, resulting in a total of five unique studies included across the analyses. For PSQI, two RCTs (n = 181) showed a non-significant but substantial magnitude of effect size (SMD = − 1.04;p = 0.5036; I²=0), while two observational studies (n = 45) demonstrated significant and large magnitude of effect size (SMD = − 1.82; p = 0.0261; I² = 79.8%). For ISI, two RCTs (n = 99) showed non-significant effect (SMD = − 1.00; p = 0.0616; I² = 71.4%). Methodological limitations including risk of bias, imprecision due to small sample sizes, and substantial heterogeneity across studies, introduce considerable uncertainty and limit the robustness of the pooled estimates.

conclusionWhile YN demonstrates potential therapeutic benefits for sleep disturbances and insomnia, the very low certainty of evidence indicates that the findings of this review should be interpreted as preliminary and hypothesis-generating. The generalizability of these findings is limited due to the geographic concentration of trials conducted in India. Future research should prioritize well-designed RCTs across diverse sociocultural settings to establish cross-cultural efficacy and global relevance.