Self-help Lifestyle Medicine for Insomnia

This study will examine the effects of a self-help smartphone-based multi-component lifestyle medicine intervention (LM) for alleviating insomnia symptoms in a Chinese population. Since a range of lifestyle factors are related to the pathogenesis and progression of insomnia, modifying different lifestyle factors simultaneously, such as diet, exercise, stress, and sleep which are empirically supported by previous reviews, may be effective to reduce insomnia symptoms (Reid et al., 2010; Vedaa et al., 2016). Traditional Chinese nutritional values will be integrated into the smartphone application to increase the acceptability towards the intervention. A prevalence study suggested that self-help interventions are preferred due to the potential stigmatization related to mental health interventions and the high cost of mental health services in Hong Kong (Lee, Tsang, \& Kwok, 2007). Nonetheless, to date, only limited self-help interventions that target lifestyle medicine for sleep-related problems are available. Through this study, we aimed to promote evidence-based patient care and improve help-seeking behaviors and access to evidence-based lifestyle interventions for insomnia.

This study will be a randomized controlled trial on the effects of a self-help smartphone-based multi-component lifestyle medicine intervention for reducing insomnia symptoms in the Chinese population. Prior to all study procedures, eligible participants will be required to complete an online informed consent (with telephone support). Assuming an alpha error of 5%, a beta error rate of 20%, and a between-group effect size of 0.77 for the Insomnia Severity Scale (Ip et al., 2020), the final sample is 28 for both groups. With an estimation of 20% withdrawal, 70 eligible participants will be randomly assigned to either the smartphone-based multi-component lifestyle medicine intervention (LM group) or the waitlist control group (WL group) in a ratio of 1:1.

Eligibility Criteria:
Inclusion Criteria:

* Hong Kong residents
* Aged ≥ 18 years
* Have an Insomnia Severity Index (ISI) score ≥10, indicating at least sub threshold level of insomnia symptoms are present
* Able to read Chinese and type in Chinese or English
* Have an Internet-enabled mobile device (iOS or Android operating system)
* Are willing to provide informed consent and comply with the trial protocol

Exclusion Criteria:

* Current involvement in psychotherapy or unstable medication for sleep, depression, and/or anxiety
* Beck Depression Inventory (BDI-II) Item 9 score of at least 2 indicating a current moderate suicidal risk that requires active crisis management (referral information to professional services will be provided to those with serious suicidal risk)
* Are having unsafe conditions and are not recommended for exercise or a change in diet by physicians
* Having major psychiatric, medical, or neurocognitive disorders that make participation infeasible or interfere with the adherence to the lifestyle modification
* Other untreated sleep disorders, including narcolepsy, obstructive sleep apnoea (OSA), and restless leg syndrome (RLS)/periodic leg movement disorder (PLMD) based on the cut-off scores (≥ 7 on narcolepsy; ≥ 15 on OSA; ≥ 7 on RLS/PLMD) of individual sections in SLEEP-50
* Shift work, pregnancy, work, family, or other commitments that interfere with regular night-time sleep patterns
* Hospitalization