Cross-method agreement between self-report and interview-based functional assessments of hikikomori: A preliminary...

Hikikomori is a state of prolonged social isolation in which individuals remain at home and disengage from work, school, and other activities. This preliminary study investigated the correspondence between self-reported scores on the Hikikomori Functional Assessment Scale (HFAS) and independently collected interview-based ratings. Consistency was evaluated at two retrospectively defined time points: the participant-designated peak period of hikikomori (Peak) and the time of assessment (Current).

A total of 16 participants (6 men and 10 women; mean age = 40.2 years) completed the HFAS and a semi-structured interview for both time points. Interviewers were masked to questionnaire responses. Data were analysed using Wilcoxon signed-rank tests and Kendall's τ correlations with Bayes factors.

Social negative reinforcement showed moderate to strong correspondence between methods at both time points (Peak: τ = 0.50, BF₁₀ = 8.9; Current: τ = 0.50, BF₁₀ = 8.6). Intrapersonal negative reinforcement indicated weak to moderate correlations and evidence at Peak (τ = 0.40, BF₁₀ = 3.0) but not at Current (τ = 0.07, BF₁₀ = 0.5). Intrapersonal positive reinforcement exhibited only anecdotal evidence of association at either time point (Peak: τ = 0.27, BF₁₀ = 1.1; Current: τ = 0.27, BF₁₀ = 1.0).

These findings provide preliminary support for the HFAS as a practical tool for identifying socially avoidant contingencies relevant to early intervention, underscoring the need for further research with larger, prospective samples.