Loneliness: A Scoping Review of Reviews From 2001 to 2023.

The growing number of primary studies and reviews on loneliness, and the multidisciplinary efforts to comprehend this complex phenomenon from various perspectives, underscore the heightened recognition of its impact on individual and societal well-being and health. To comprehensively assess the size and scope of this research field, we conducted a scoping review of 35 English-language reviews of primary studies on loneliness, published between 2001 and 2023. Focusing specifically on psychological research, these reviews covered a total of N = 1,089 studies, which were conducted between 1986 and 2022. In addition to providing a broad overview of the structure of the field, the present scoping review aimed to explore the methodological landscape of loneliness research, including data collection, sample demographics, and measures, and to present key topics and evidence in the field. By deepening the understanding of loneliness and identifying data gaps and methodological challenges, our analyses provide critical insights for future research endeavors, thereby fostering advances in the field.