DMH Intervention Program Only
depression, third-wave, depressive, anxiety
Treatment was delivered within a secure and encrypted digitally based treatment platform and comprised the primary intervention for all 3 treatment conditions: a third-wave, transdiagnostic biopsychosocial DMH intervention program called Life Flex. The treatment in step 1 of the trial comprised the Life Flex program only, whereby participants completed the self-help program Life Flex without therapist assistance. All participants received automated emails to inform them of the module content as well as the release and reminders of scheduled assessments. Participants completed the program on a scheduled release design, with a new module being released every week except for module 4 (participants were given 2 weeks to work through and practice module 4 content). Participants who improved or engaged with the Life Flex program within the first 3 weeks maintained their no-therapist-assistance DMH intervention program.The aim of the Life Flex program is to increase psychological flexibility and positive affect in anxiety and depression. The program incorporates CBT, emotion regulation strategies, and neuroplasticity principles. The Life Flex program is suitable for individuals with or without a diagnosis of anxiety or depression and contains 6 core modules along with an introductory and booster module. Each module of the program takes approximately 25 minutes to complete. In addition, to reinforce the module-based information, there are 20 to 30 minutes of offline activities each week.Offline activities include applying the concepts and techniques discussed in the modules (eg, self-monitoring of depressive and anxiety symptoms), undertaking one of the biological and wellness flexibility intervention strategies, monitoring emotions and thoughts, and undertaking the gradual exposure or behavioral activation activities. Participants also receive automated emails (eg, to remind them to log on or complete the questionnaires) and are asked several questions at the beginning of each module to help gauge their progress. Module features include text, graphics, audio, video, editable forms, web-based games (eg, cognitive bias modification), and downloads. Modules are accessible via the web on mobile or tablet devices. Further information regarding the modules of the Life Flex program is presented in 