School Ijime (Bullying) Experience Is a Possible Risk Factor for Current Psychological Distress among Science City Workers: A Cross-Sectional Study in Tsukuba, Japan.

Early-life adversities are considered to have long-term impact on health. There have been many studies regarding the experience of being bullied and its harmful psychological influence, but such influence on workers remains to be investigated in Japan. We therefore aimed to examine the prevalence of workers with experiences of being bullied or bullying others during childhood and adolescence and to clarify the relation between those experiences and current psychological distress. A cross-sectional study using an anonymous self-report web questionnaire was conducted in November 2017. The study population was 19,481 workers belonging to the Tsukuba Science City Network, and we analyzed the data of 6,015 participants (3,715 men and 2,300 women, aged between 20 years and 59 years). The percentages of participants with experiences of being bullied were 51.5% for men and 56.2% for women; those with experiences of bullying others were 36.5% of men and 29.4% of women. Relations between experiences of bullying and psychological distress were assessed using Chi-squared tests. Logistic regression analyses with psychological distress as an objective variable and experiences of bulling as explanatory variables were performed using those who had no bulling experiences as control. In both men and women, experiences of being bullied were significantly associated with psychological distress after adjustment socioeconomic factors (the odds ratios were 1.26 for men (95% CI = 1.05-1.52) and 1.72 for women (95% CI = 1.39-2.13)). Consideration of past social experiences, such as being bullied, is useful for mental health management among workers reporting psychological distress.