• deliberate self-harm;
  • Internet;
  • search engine;
  • self-injury;
  • young adults

This study aimed to clarify the association between the experience of searching for deliberate self-harm (DSH)-related Internet content and the mental states and lifetime suicidal behaviors of Japanese young adults (n = 1000) using an online questionnaire. The results were assessed using χ2 and t-tests, which revealed that the experience of DSH-related Internet searches may be significantly associated with lifetime suicidal behaviors (including DSH), suicidal ideation, and tendencies towards depression/anxiety. We discussed the possibility of using search engines to increase the motivation of Japanese young adults who deliberately harmed themselves with regard to seeking help.