[Sportschosun reporter Jang Jong-ho] Depression and bipolar disorder often relapse even after responding well to medication, making relapse prevention a key treatment goal. A South Korean research team has now drawn attention after proving through a rigorously designed large-scale clinical trial that an app which corrects "circadian rhythms" measured by smartphones and wearable devices in daily life can significantly reduce relapse in mood disorders.
The research team led by Professor Heon-Jeong Lee of the Department of Psychiatry at Korea University Anam Hospital, with Yeom Ji-won and Professor Jung Jae-kwon as first authors, said it recently published the results of a multicenter clinical trial of CRM (Circadian Rhythm for Mood), a digital therapeutic app based on circadian rhythms, in the online edition of the American Journal of Psychiatry, one of the most prestigious international journals in psychiatry.
◇ Beyond symptom management: a digital therapy targeting relapse prevention and circadian rhythms
Mood disorders can recur repeatedly even after improvement, placing a heavy burden on both patients and caregivers. Medication is effective in stabilizing symptoms, but it has limits when it comes to maintaining long-term stability and preventing relapse. That has led to calls for complementary approaches with different mechanisms of action.
CRM, developed by the research team, is based on the hypothesis that instability in circadian rhythms triggers mood episodes. When the body clock, which repeats on an approximately 24-hour cycle, becomes disrupted, depressive or manic episodes can be triggered. CRM focuses on stabilizing that rhythm in everyday life. Its episode-prediction algorithm relies entirely on data automatically collected from wearables and smartphones.
Specifically, CRM analyzes activity levels, heart rate, sleep data collected from wearable devices, and light exposure measured through smartphone light sensors to predict mood states over the next three days as low, moderate, or high. Based on individual circadian rhythm indicators estimated from wearable and smartphone sensor data, it also provides personalized behavioral guidance and alerts, such as the optimal wake-up time, light exposure timing, and strategies to stabilize activity rhythms. In other words, it uses automatically measured, daily personalized information delivered through a smartphone app to help patients build and maintain healthier circadian routines.
◇ Relapse risk cut to about one-third: double-blind clinical trial compared with a sham app
The study was designed as a multicenter, double-blind, sham-controlled randomized clinical trial conducted at five university hospitals nationwide, including Korea University Anam Hospital, Korea University Guro Hospital, Korea University Ansan Hospital, Inje University Ilsan Paik Hospital, and Pusan National University Hospital. The team randomly assigned 93 adult patients diagnosed with depression or bipolar disorder and currently in a stable state to either a CRM app group with actual therapeutic functions (47 patients) or a sham app group with the same appearance but no therapeutic effect (46 patients), then followed them for one year. The study was conducted without either patients or researchers knowing which app was being used, increasing the reliability of the results.
The analysis found that the relapse rate for mood episodes in the sham app group was about 3.4 times higher than in the CRM app group. When 100 people were observed for one year, the number of relapses was 41.1 in the CRM app group, compared with 139.3 in the sham app group. The duration of episodes after relapse was also longer in the sham app group, and the time to first relapse was significantly longer in the CRM app group. The team said these findings show that CRM may help reduce relapse in patients with depression and bipolar disorder, speed recovery after relapse, and maintain stability for longer periods.
When depressive and hypomanic episodes were analyzed separately, the CRM app group generally showed better results. However, the team added that caution is needed in interpreting manic episodes because the number of cases was very small, at just four.
No serious adverse events related to app use were reported during the study period, suggesting positive results in terms of safety as well.
◇ "Confirmed potential as a digital therapy to complement medication... follow-up studies to identify the mechanism"
Professor Heon-Jeong Lee, the corresponding author, explained, "Relapse in mood disorders is often not just a recurrence of symptoms, but stems from a mismatch in circadian rhythms involving light exposure and activity." He added, "CRM showed that by reflecting an individual's daily pattern in real time and adjusting the body clock accordingly, it can become a scalable digital therapeutic device that complements medication."
First authors Yeom Ji-won and Professor Jung Jae-kwon said, "This is the first time a digital therapeutic that derives circadian rhythm phenotypes from passive sensor data and provides personalized feedback has been validated in a double-blind, sham-controlled trial." They added, "We plan to continue with larger studies using improved UI/UX and to identify the mechanism of action based on biomarkers."
Meanwhile, the CRM app was developed by Huseo Circadian, a subsidiary of Korea University Medical Center's Medical Technology Holding Company, and Professor Lee is a co-founder of the company. Huseo Circadian provided only the app platform and did not participate in the study design, data collection, analysis, or interpretation. The study was supported by the National Research Foundation of Korea and the Ministry of SMEs and Startups' Technology Development Project.
Jang Jong-ho, reporter bellho@sportschosun.com
