Association Between Loneliness and Hikikomori Symptoms. A Systematic Review and Meta-Analysis

A systematic review and meta-analysis were conducted to investigate the association between loneliness and hikikomori symptoms.

We searched three electronic databases (plus hand search). Our review followed the PRISMA guidelines, and a PROSPERO registration was made. We included observational studies determining the association between loneliness and hikikomori symptoms.

Eight cross-sectional studies were finally included. Our psychometric meta-analysis revealed a mean corrected correlation of 0.68 (95% CI: 0.62 to 0.74). The mean corrected correlations of loneliness with the subscales socialization, isolation, and emotional support were 0.54 (95% CI: 0.50 to 0.58), 0.62 (95% CI: 0.60 to 0.64), and 0.71 (95% CI: 0.67 to 0.75), respectively. The mean corrected correlation for the association between loneliness and hikikomori symptoms was 0.66 (95% CI: 0.62 to 0.70) among European countries, whereas it was 0.90 (95% CI: 0.81 to 0.99) among Asian countries. Five of the studies were of good quality, and three were of fair quality.

Our work identified a strong, positive association between loneliness and hikikomori symptoms. Upcoming longitudinal studies are required to clarify the directionality between such factors. There is also a clear need for research in regions that have been neglected so far.