A Study of Factors Having Suicidal Thoughts in the Japanese

Japan’s suicide death rate is one of the highest in the world, especially among young people. According to a 2022 survey, about half of young people have had feelings of wanting to die in the past. In order to solve this problem, it is necessary to listen to the actual voices of those who have suicidal thoughts and understand their backgrounds and factors. The purpose of this study is to capture the events that contribute to Japanese people having suicidal thoughts from the actual text data submitted. In addition, by creating time-series data, we will visualize how the factors that cause people to have suicidal thoughts are changing. Using the data of questions posted on Yahoo! Chiebukuro, we extracted questions containing “Shinitai” (English: wanting to die) and conducted co-occurrence network analysis by nouns. From the co-occurrence network analysis, we were able to divide the nouns that frequently occur in the actual statements of people who have suicidal thoughts into six groups. Next, for each of the extracted nouns, we obtained the TF value (Term Frequency) over a period of time and observed its change over time in order to measure how much the word accounted for the sentences posted over a given period of time. There was a strong change in values from month to month, and no significant increase or decrease in the yearly transition was observed. Observations by time period showed that some words had higher TF values at certain times of the day.