ObjectiveTo systematically evaluate the efficacy of hyperbaric oxygen therapy for non-motor symptoms in patients with Parkinson's disease.Data sourcesA systematic search was performed across several databases, including the Chinese Science and Technology Periodical Database, Web of Science, SinoMed, PubMed, Cochrane Library, Embase and Wanfang databases up to 1 December 2024. Studies considered for inclusion comprised randomised controlled trials and pre-post control studies.Review methodsThe authors conducted the data extraction and literature screening procedures independently. The selected studies' quality was evaluated using the Cochrane risk of bias technique. Review Manager 5.3 was used to conduct meta-analyses, while Stata 15.0 was utilised for sensitivity analysis and to assess publication bias.ResultsSixteen studies with a total of 1324 individuals satisfied the inclusion criteria. The results of the meta-analysis showed that hyperbaric oxygen therapy significantly improved scores on the Hamilton Anxiety Scale and Hamilton Depression Scale compared with baseline (both