The Impact of Media Reports on the 2008 Outbreak of Hydrogen Sulfide Suicides in Japan

Objective: Japan experienced a nationwide outbreak of hydrogen sulfide suicides (HSS) between April and May 2008. The annual number of HSS skyrocketed from 19 in 2007 to 1,056 in 2008. However, the factors affecting this enormous increase remain unknown. The present study aimed to examine the effect of media coverage of the incidents on the subsequent epidemic of HSS. Method: We collected time series data from the 1st week of February to the last week of September 2008 (34 weeks), including the number of HSS (St), the number of articles on HSS published in the five major newspapers (Nt), and the number of Internet searches with the keyword “hydrogen sulfide suicide” (Gt). The generalized method of moments was applied to model the concurrent effects of Nt and Gt on St. Results: The increase in the number of newspaper articles significantly induced the increase in HSS (coefficient, 0.84; 95% confidence interval (CI), 0.28–5.3), while the number of Internet searches did not significantly affect the number of HSS (coefficient, −0.75; 95%CI, −19.3–0.45). Conclusions: Exposure to information on HSS from newspaper articles could have directly affected the subsequent increase in the number of suicides. On the other hand, the number of the Internet searches did not have a direct influence on HSS.