Self-help Lifestyle Medicine App and Booklets for Depression

This study aims to compare self-help lifestyle medicine (LM) delivered by a smartphone app and booklets in managing depressive symptoms in a Chinese population.

This study is a randomised controlled trial. First, informed consent will be obtained from potential participants. Around 90 eligible participants will be randomly assigned to either the LM app group, the LM booklet group, and the waitlist control group, in a ratio of 1:1:1. The app group will receive an app to facilitate lifestyle modification such as video demonstrations of physical activity, diet recommendations, stress and sleep management. The booklet group will receive 8 LM booklets with identical content with the LM app. The waitlist control group will receive access to the app and booklets at the end of the study. The whole intervention lasts 8 weeks. Participants will also receive 2 messages per week from the researcher to check and prompt motivation and adherence. Participants will complete assessment before, immediately after intervention, at one month and 12-week follow up.

As lifestyle plays an important role in the pathogenesis of depression, lifestyle medicine (LM) emerges as a new way to alleviate depressive symptoms (Sarris \& O'Neil, 2016). Booklets have been shown as an inexpensive and effective delivery modality of lifestyle modification among individuals with physical conditions (Wong, Chair \& Wong, 2017). Meanwhile, a recent meta-analysis supports the efficacy of mobile applications in improving depressive symptoms (Linardon, Cujipers, Carlbring, Messer \& Fuller-Tyszkiewicz, 2019). Notably, the efficacy of lifestyle intervention using booklets and app have not been compared. This pilot study can inform the field about the efficacy of lifestyle intervention using two self-help delivery modalities and offer new ways to better managing depressive symptoms.

This study will be a randomised controlled trial comparing self-help LM delivered by a smartphone app and booklets in improving depression. For a pilot study, a sample size of 12 per group is recommended (Julious, 2005). Considering an estimation of 20% attrition at the three assessment time points, the final sample size is 90, with 30 participants in each group.

The LM booklet group will receive a pocket size 6-page booklet weekly that covers 8 lifestyle medicine themes including stress, relaxation, diet, exercise, sleep hygiene, worry management, mindfulness, and positive psychology. Exercises based on cognitive behavioural therapy and guidance to set and meet short term and long-term goals are featured in the booklets. The booklet series is reviewed by a panel of experts including clinical psychologists, psychiatrists, dietitians, physical trainers, and traditional Chinese Medicine practitioners. The app group will receive access to a mobile app that offers 8 modules with identical content as the wellness booklets, in addition to videos, relaxation, exercise and cooking demonstrations, daily challenges and record of goals. The waitlist control group will receive access to the app and booklets at the end of the study.

Eligibility Criteria:
Inclusion Criteria:

* Participants with elevated depressive symptoms as defined by PHQ-9 score 10 or above
* Hong Kong residents
* Aged 18 or above
* Able to read Chinese and type in Chinese or English
* Have an Internet-enabled mobile device (iOS or Android operating system)

Exclusion Criteria:

* Pregnancy;
* Using medication or psychotherapy for depression;
* Currently participating in other psychological intervention studies;
* Cognitive impairment;
* Having unsafe conditions and are not recommended for physical activity or a change in diet by physicians;
* Self-disclosure of any major psychiatric, medical, or neurocognitive disorders that make participation unsuitable or may interfere with the adherence of the lifestyle modification;
* Any suicidal ideation (scoring above 2 in item 9 in BDI-II) Participants with any urgent health necessity were excluded and referred.