Effectiveness of an Internet-Based, Self-Guided, Short-Term Mindfulness Training (ISSMT) Program for Relieving Depressive Symptoms in the Adult Population in China: Single-Blind, Randomized Controlled Trial

BACKGROUND: Depression is a significant global public health issue, and in China, access to mental health services remains limited despite high demand. Research has shown that mindfulness can effectively alleviate depressive symptoms and that telehealth solutions offer a promising avenue for addressing this service gap. Despite this potential, there are currently few studies in China focusing on short-term online mindfulness training. Most existing online mindfulness studies relied on traditional 8-week programs, which can be challenging for participant adherence due to limited accessibility and high dropout rates. Additionally, limited research exists on short-term online mindfulness interventions, and findings remain inconsistent. OBJECTIVE: This study aimed to develop and evaluate an internet-based, self-guided, short-term mindfulness training (ISSMT) program based on the Monitor and Acceptance Theory (MAT) to reduce depression symptoms. METHODS: The ISSMT program was delivered via an online platform, "Hi Emotion," and was accessible to the general public. Interested individuals aged 18 years and older were randomized into either the ISSMT group or a wait-list control group. Participants in the ISSMT group received daily reminders to participate in a 15- to 20-minute session over a 14-day training period. Measurements, including mindfulness and depressive symptoms, were collected at baseline and weekly for the subsequent 3 weeks. RESULTS: A total of 205 adults participated in the 14-day online intervention. Linear mixed models were used to analyze both per-protocol (PP) and intention-to-treat (ITT) samples. Compared with the wait-list control group, participants in the ISSMT group showed significant improvements in mindfulness (Cohen d=0.44 for ITT; Cohen d=0.55 for PP) and reductions in depressive symptoms (Cohen d=0.50 for ITT; Cohen d=0.53 for PP). Furthermore, participants expressed high acceptance of this training format with a relatively low dropout rate (<40%). CONCLUSIONS: The ISSMT program based on the MAT effectively enhanced mindfulness and alleviated depressive symptoms. This intervention could be considered for integration into psychosocial service systems to improve mental health outcomes and help bridge the gap between limited resources and the high demand for services in China. Future research should focus on personalizing these programs and incorporating advanced technologies to enhance their effectiveness and user engagement. TRIAL REGISTRATION: Open Science Framework; https://doi.org/10.17605/OSF.IO/8P4V6.