Social network disruption as a major factor associated with psychological distress 3 years after the 2004 Niigata-Chuetsu earthquake in Japan.

Objectives: The 2004 Niigata-Chuetsu earthquake of Japan caused a great deal of damage, and people living in the affected region are still struggling to reconstruct their lives. The aim of this study was to determine factors associated with psychological distress in people living in a town at the epicenter 3 years after the earthquake.

Methods: We conducted a cross-sectional study from June 2007 to January 2008. Participants included 225 individuals living in Kawaguchi (age ≥20 years) who reported psychological symptoms. Information on family structure, employment status, alcohol use, social network, and extent of house damage was elicited by public health nurses conducting structured interviews. Levels of psychological distress were assessed with the Kessler Psychological Distress Scale (K10), with a K10 score ≥25 defined as psychological distress.

Results: The mean age of participants was 66.1 ± 12.9 years. The prevalence of psychological distress varied among different employment classes, being 5/73 (6.8%) for participants with paid employment, 12/50 (24.0%) for full-time housewives, and 11/101 (10.9%) for those who were unemployed (χ(2) = 8.42, P = 0.015). It also varied between participants who had lost contact with people in the community and those who had no change in social contact [9/20 (45.0%) vs. 19/189 (10.1%), respectively; χ(2) = 19.04, P < 0.001]. Multiple logistic regression analysis showed that age [odds ratio (OR) 0.95, 95% confidence interval (CI) 0.91-0.98], poor or loss of contact with people in the community (OR 6.97, 95% CI 1.85-26.2), and lack of employment (full-time housewives or unemployed individuals) (OR 6.74, 95% CI 1.62-28.0) were associated with psychological distress.

Conclusions: People who lose their social network are at a very high risk for post-earthquake psychological distress and require appropriate care.