health promotion among university students: a fully factorial randomized study

INTERVENTION: 2^5*2=64 combinations of five components of smartphone CBT, with randomized sequence between cognitive restructuring and behavioral activation Each component will consist of one lesson, which normally takes 7‐10 days. In the factorial design, each component will be compared among those combinations with or without that component. 2^5*2=64 combinations of five components of smartphone CBT, with randomized sequence between cognitive restructuring and behavioral activation CONDITION: Graduate and undergraduate students in Japanese universities PRIMARY OUTCOME: The primary outcome of Analysis 1 is self‐administered Personal Health Questinnaire‐9 (PHQ‐9) at week 8.; The primary outcome of Analysis 2 is incidence of a major depressive episode as assessed by the major depressive episode section of the computerised Composite International Diagnostic Interview (CIDI) at week 52. INCLUSION CRITERIA: 1. University students enrolled in full‐time undergraduate or graduate programs at the participating universities a. Aged between 18 and 39 at time of enrollment. The upper age limit of 39 was adopted in order to secure homogeneity of the participants within adolescence to young adulthood. b. Of either sex 2. They must have their own smartphone, either an Apple iPhone or Android device. 3. They must provide written informed consent to participate in this study after full disclosure of the contents and procedures of the study. 4. They must have completed the PE component within 2 weeks after providing their consent.