Early-pregnancy ALT, AST, and GGT in relation to gestational diabetes: a GGT-focused association pattern.

Hikikomori is a severe and prolonged form of social withdrawal characterized by marked social isolation in the home for at least 6 months and associated with significant functional impairment or distress (). Although related forms of social withdrawal had been described earlier, the concept of hikikomori gained broad recognition in Japan following work and was initially discussed largely within a Japanese sociocultural framework (; ; ; ). Subsequent literature, including case reports, clinical studies, survey-based investigations, and review articles, has described a range of hikikomori-related phenomena, including clinically assessed cases, hikikomori-like presentations, and survey-identified patterns of severe social withdrawal, across diverse cultural contexts such as South Korea, China, Italy, Spain, France, Turkey, and the United States (; ; ; ; ; ; ). This growing international evidence has contributed to a shift from viewing hikikomori primarily as a Japan-specific phenomenon toward recognizing its broader cross-cultural relevance and potential global mental health implications (; ; ). The estimated lifetime prevalence in Japan ranges between approximately 1.2 and 2%. Studies based on general population samples indicate that hikikomori-like social withdrawal is not limited to Japan but is also observed in different countries (; ; ). Hikikomori is a multidimensional phenomenon associated with substantial psychological, social, and functional difficulties, extending beyond individual distress to broader disruptions in education, employment, and social participation (; ). Prolonged social withdrawal can involve disengagement from education or employment, reduced social participation, and broader functional impairment (; ; ). It has also been associated with depression, anxiety, suicidal ideation, and psychotic phenomena, particularly delusional experiences (; ; ). Recent evidence has further linked higher hikikomori tendencies to lower perceived social support and psychological resilience, as well as to greater unemployment anxiety and learned meaninglessness. These findings point to the potential relevance of social resources, adaptive psychological capacities, unemployment-related concerns, and meaning-related processes in social withdrawal (; ). Adolescence and early adulthood represent particularly vulnerable developmental periods, during which identity formation and transitions into adult social and occupational roles are central (; ). Evidence linking identity distress to more severe trajectories of hikikomori symptoms suggests that social withdrawal during these periods may complicate participation in education, employment, and broader social life (; ). The COVID-19 pandemic has further intensified concerns about prolonged social withdrawal. Lockdowns, reduced in-person contact, and greater reliance on online lifestyles have been discussed as conditions that may increase the risk of hikikomori-like withdrawal, which has also been considered a potential longer-term mental health consequence of the pandemic (; ). Research on hikikomori has increased markedly over the past decade, with a growing body of literature addressing its definition, prevalence, and associated factors. proposed an internationally applicable diagnostic framework, while developed a structured assessment tool to support this framework. Reviews by , have deepened the understanding of the demographic and clinical characteristics of hikikomori, and have provided a detailed examination of its psychiatric comorbidities. In addition, and have highlighted its associations with technology use and digital addiction, whereas have emphasized psychosocial dimensions such as attachment and environmental sensitivity. This body of work indicates that hikikomori research has not only expanded in volume but has also become more diverse in its theoretical and methodological approaches, moving toward a more integrated understanding of the phenomenon. This growing interest has also led to a limited number of studies that examine the hikikomori literature using bibliometric approaches. analyzed 297 publications retrieved from the Web of Science database, identifying publication trends, leading authors and countries, and keyword networks. Similarly, examined 286 publications based solely on the Scopus database, focusing on the developmental trajectory and academic distribution of the field. , using CiteSpace, conducted a scientometric analysis of 302 publications, mapping document co-citation clusters and country collaboration networks. While these studies provide valuable insights into the structural characteristics of the hikikomori literature, they present certain limitations in terms of database coverage and analytical depth. Relying on a single database increases the risk of database-specific bias, and the restriction of their data to publications up to 2022 limits their ability to capture the rapid growth observed in recent years. In