Association of Chronic Pain and Loneliness With Abusive Behaviors Toward Family Members and Older Adults: A Population-Based Cross-Sectional Study in Japan.

Chronic pain is associated with mood dysregulation, irritability, and impaired emotion regulation. However, population-based evidence linking chronic pain to abusive behaviors toward older adults remains limited. This study examined (a) the prevalence of verbal and physical abusive behaviors toward family members and older adults according to chronic pain status and (b) the independent and joint associations of chronic pain history and loneliness with these behaviors. We analyzed pooled cross-sectional data from 39,173 adults (mean age: 46.4 years; 51.6% women) who participated in the Japan COVID-19 and Society Internet Survey in 2022 and 2023. Chronic pain status (current, past, or none) was assessed by self-report, loneliness was measured using the six-item De Jong Gierveld Loneliness Scale, and abusive behaviors in the past year were assessed via single-item questions. Modified Poisson regression models estimated prevalence ratios (PRs) with 95% confidence intervals (CIs), adjusting for sociodemographic, lifestyle, and mental health factors. After full adjustment, current chronic pain was significantly associated with a higher prevalence of verbal aggression toward family members (PR 1.54, 95% CI [1.45, 1.63]), verbal aggression toward older adults (PR 1.35, 95% CI [1.23, 1.47]), and physical violence toward family members (PR 1.41, 95% CI [1.30, 1.52]), but not significantly associated with physical violence toward older adults. Participants with both a history of chronic pain and high loneliness had the largest adjusted PRs across outcomes; however, RERI estimates showed no statistically significant departure from additivity. Given the cross-sectional design and self-reported measures, these findings should be interpreted as associations that may reflect broader accumulated vulnerability rather than direct causal effects. The findings suggest that pain management and primary care settings may serve as contact points for identifying interpersonal conflict and that screening for loneliness and broader psychosocial vulnerability may facilitate early identification of individuals at elevated risk.