Neuropsychiatric disorders arise from complex interactions between genetic and environmental factors. DNA methylation, a reversible and environmentally responsive epigenetic regulatory mechanism, serves as a crucial bridge linking environmental exposure, gene expression regulation, and neurobehavioral outcomes. During long-duration deep-space missions, astronauts face multiple stressors-including microgravity, cosmic radiation, circadian rhythm disruption, and social isolation, which can induce alterations in DNA methylation and increase the risk of neuropsychiatric disorders. Genome-wide DNA methylation research can be divided into 3 major methodological stages: Study design, sample preparation and detection, and data analysis, each of which can be applied to astronaut neuropsychiatric health monitoring. Systematic comparison of the Illumina MethylationEPIC array and whole-genome bisulfite sequencing reveals their complementary strengths in terms of genomic coverage, resolution, cost, and application scenarios: the array method is cost-effective and suitable for large-scale population studies and longitudinal monitoring, whereas sequencing provides higher resolution and coverage and is more suitable for constructing detailed methylation maps and characterizing individual variation. Furthermore, emerging technologies such as single-cell methylation sequencing, nanopore long-read sequencing, and machine-learning-based multi-omics integration are expected to greatly enhance the precision and interpretability of epigenetic studies. These methodological advances provide key support for establishing DNA-methylation-based monitoring systems for neuropsychiatric risk in astronauts and lay an epigenetic foundation for safeguarding neuropsychiatric health during future long-term deep-space missions.
DNA Methylation ; Humans ; Space Flight ; Mental Disorders/genetics* ; Epigenesis, Genetic ; Astronauts/psychology* ; Weightlessness/adverse effects* ; Epigenomics

Since 2016, a number of studies have been published on standard decoctions used in Chinese medicine. However, there is little research on statistical issues related to establishing the quality standards for standard decoctions. In view of the currently established quality standard methods for standard decoctions, an improvement scheme is proposed from a statistical perspective. This review explores the requirements for dry matter yield rate data and index component transfer data for the application of two methods specified in “Technical Requirements for Quality Control and Standard Establishment of Chinese Medicine Formula Granules,” which include the average value plus or minus three times the standard deviation (X-±3SD) or 70% to 130% of the average value (X-±30%X-). The square-root arcsine transformation method is used as an approach to solve the problem of unreasonable standard ranges of standard decoctions. This review also proposes the use of merged data to establish a standard. A method to judge whether multiple sets of standard decoction data can be merged is also provided. When multiple sets of data have a similar central tendency and a similar discrete tendency, they can be merged to establish a more reliable quality standard. Assuming that the dry matter yield rate and transfer rate conform to a binomial distribution, the number of batches of prepared slices that are needed to establish the standard decoction quality standard is estimated. It is recommended that no less than 30 batches of prepared slices should be used for the establishment of standard decoction quality standards.