Examining Tweet Content and Engagement of Users With Tweets About Hikikomori in Japanese: Mixed Methods Study of Social Withdrawal

Victor Pereira-Sanchez   ^{1, 2, 3, 4} , MD, PhD ;   Miguel Angel Alvarez-Mon   ^{5, 6} , MD, PhD ;   Toru Horinouchi   ⁷ , MD ;   Ryo Kawagishi   ⁸ , MD ;   Marcus P J Tan   ⁹ , BSc, MRCPsych ;   Elizabeth R Hooker   ¹⁰ , MS, MD ;   Melchor Alvarez-Mon   ^{5, 11} , MD, PhD ;   Alan R Teo   ^{10, 12} , MD, MS

¹ Department of Child and Adolescent Psychiatry, NYU Grossman School of Medicine, New York, NY, United States

² Department of Psychiatry, Columbia University, New York, NY, United States

³ Division of Translational Epidemiology, New York State Psychiatric Institute, New York, NY, United States

⁴ Department of Psychiatry and Clinical Psychology, Clinica Universidad de Navarra, Pamplona, Spain

⁵ Department of Medicine and Medical Specialties, Faculty of Medicine and Health Sciences, University of Alcala, Alcala de Henares, Spain

⁶ Department of Psychiatry and Mental Health, Hospital Infanta Leonor, Madrid, Spain

⁷ Department of Psychiatry and Neurology, Hokkaido University Graduate School of Medicine, Hokkaido, Japan

⁸ Department of Psychiatry, Chiba Psychiatric Medical Center, Chiba, Japan

⁹ Department of Child and Adolescent Psychiatry, South London and Maudsley NHS Foundation Trust, London, United Kingdom

¹⁰ VA Portland Health Care System, Health Services Research & Development Center to Improve Veteran Involvement in Care, Portland, OR, United States

¹¹ Immune System Diseases-Rheumatology, Oncology Service and Internal Medicine, Hospital Universitario Principe de Asturias, Alcalá de Henares, Spain

¹² Department of Psychiatry, Oregon Health & Science University, Portland, OR, United States