Loneliness and social isolation have become crucial in Japan, but research on how loneliness has changed over time is lacking. This study conducted a cross-temporal meta-analysis to address this gap. Studies were identified from PubMed, Web of Science, J-Stage, and CiNii; exclusion criteria were mis... Link: https://www.frontiersin.org/articles/10.3389/fpsyg.2026.1824941 :Cat-PS