BACKGROUND AND AIM: Substance use disorders (SUDs) contribute significantly to global social and economic burden. Breathing-based interventions offer a low-cost, scalable adjunct or alternative to traditional treatment, yet their effects on substance use-related outcomes has not been systematically evaluated. This study aimed to systematically review and meta-analyse the effectiveness of controlled breathing and heart rate variability biofeedback (HRVB) interventions in improving substance use-related outcomes among people using alcohol and other drugs, including nicotine.

METHODS: Web of Science, PsycINFO, MEDLINE, CINAHL, EMBASE, PubMed, Scopus and Cochrane were searched, with the final search conducted on 14 November 2025. The protocol was prospectively registered with the International Prospective Register of Systematic Reviews. Eligible studies were quantitative, with repeated-measure designs, with at least one substance use-related outcome; interventions were required to have controlled breathing as the primary mechanism and were categorised by inclusion of HRVB. The review followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. A random-effects model was used to estimate pooled effects.

RESULTS: Of 3502 studies identified, 20 met the inclusion criteria, of which 15 were eligible for meta-analyses. Breathing-based interventions produced lower craving than controls, with a small but statistically significant and consistent effect [Hedge's g = 0.30, 95% confidence interval (CI) = 0.12-0.48, heterogeneity (I) = 23.5%, 12 studies, 696 participants]. Effects on withdrawal symptoms were uncertain compared with controls (g = 0.46, 95% CI = -0.28 to 1.19, I = 89.7%, 4 studies, 289 participants), while larger effects were observed for substance dependence compared with control (g = 0.85, 95% CI = 0.21-1.48, I = 70.9%, 2 studies, 144 participants). For the craving outcome, no difference between type of breathing intervention (HRVB vs. other) was identified [Q between (1) = 0.17, P = 0.68].

CONCLUSIONS: In people who use substances, breathing-based interventions appear to lead to statistically significant reductions in craving compared with controls, supporting their potential as a low-cost and scalable strategy for managing craving in substance use disorders.