The problem of the selection of biological material in the epygenetic research of psychological characteristics

Brain tissue during life is directly inaccessible to epigenetic studies of psychological characteristics and psychopathologies, so it is necessary to assess which peripheral tissues are most appropriate for achieving the goals of such studies. The article presents the analysis of publications comparing methylation DNA profile in various peripheral tissues (whole and umbilical blood, placenta, sperm, buccal epithelium) and postmortal brain tissue. The results of the analysis suggest that for studying the role of epigenetic factors in psychological phenotypes, saliva is the more preferred material for DNA isolation and subsequent analysis of DNA methylation compared to blood cells. At the same time, it was established that different tissues can be optimal for different phenotypes.