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Innovative Research Program on Suicide Countermeasures in FY2021: Report on Commissioned
Research Results

Field 3: Developing new policy areas
Topic number：3-1
Research topic:
Research on Suicide Countermeasures Using Social Media

Principal Researcher:
Akihito Shimazu
Professor, Faculty of Policy Management, Keio University

Co-Researcher:
Yoko Hamada
Professor, Faculty of Environment and Information Studies, Keio University

Sachiko Mori
Professor, Faculty of Policy Management, Keio University

Akiyoshi Okada
Professor, Faculty of Environment and Information Studies, Keio University

Tadashi Okoshi
Associate Professor, Faculty of Environment and Information Studies, Keio University

Jin Nakazawa
Professor, Faculty of Environment and Information Studies, Keio University

Emiko Ban
Project Assistant Professor, Graduate School of Media and Governance, Keio University

Masahito Tokita
Senior Researcher, Keio Research Institute at SFC1

【 課題番号 3-1 】

Summary:

The purpose of this research project was to explore the relationship between social media usage and mental
health. To gather objective evidence, we developed a smartphone application that collects log data on
smartphone usage Three studies were conducted.
Study 1: A study on the relationship between smartphone operating systems and users' psychosocial
characteristics
Due to technical limitations, log data collection in this study was limited to smartphones with the AndroidOS. Therefore, we conducted a web survey of 400 university students (200 each from Android and iOS, 50 fromeach of the four grades, 138 males and 262 females) registered with a research company, with the aim ofexploratory clarifying differences in the socioeconomic status, mental health status, etc. of smartphone users
depending on their smartphone OS (2021). The survey was conducted from September 30 to October 4, 2021.
The results revealed that there were differences in socioeconomic status and length of time spent on social media
depending on the OS used.
Studies 2 and 3: Relationship between social media usage and mental healthStudies 2 and 3 consisted of an observational study (Empirical Sampling Method) using a smartphone
application (SML) and a web survey at two-time points before and after the observation period. The participantsof the study were university students registered with a research firm and using the Android operating system. Atotal of 200 participants were recruited, 25 from each of the eight categories of grade (4 grades) × gender(male/female), and 174 participants (86 males and 88 females) cooperated in the study. In the observational
study, participants installed an application (SML) on their smartphones, and data on start and end times of use
were collected for each SM type. Participants also completed daily self-monitoring items related to mood andemotion. The observational study lasted 19 days (December 6-24, 2021), and Web surveys were conducted at
two-time points before and after the observational study (T1: November 29-December 3, 2021; T2: December
25, 2021-January 6, 2022). Study 2 used web survey data from two-time points, and Study 3 used log data to
examine the association between social media use and mental health. It was found that the relationship between2

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usage and mental health differed depending on the type of social media.

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