Digital Phenotypes for Predicting Depression

You may be eligible if

• 1. Adults aged 19 to 75 years and 11 months.
• 2. Diagnosed with a major mood disorder (bipolar I or II disorder, or major depressive disorder) based on DSM-5, with a history of psychiatric visits for mood symptoms.
• 3. Has experienced at least one prior depressive episode (major, minor, or brief).
• 4. Owns a smartphone with stable internet connectivity, can operate it without difficulty, and agrees to install a digital phenotyping application, wear a Fitbit device daily, and complete daily mood logs throughout the study period.
• 1. Adults aged 19 to 75 years and 11 months.
• 2. No current or past diagnosis of bipolar disorder or major depressive disorder.
• 3. Scores below clinical thresholds on both K-MDQ (\<7) and PHQ-9 (\<5) at baseline assessment.
• 4. Owns a smartphone with stable internet connectivity, can operate it without difficulty, and agrees to install a digital phenotyping application, wear a Fitbit device daily, and complete daily mood logs throughout the study period.
• 1. Adults aged 19 to 75 years and 11 months.
• 2. No current or past diagnosis of bipolar disorder or major depressive disorder.
• 3. Meets either of the following:
• A. Scores above the threshold on K-MDQ (≥7) or PHQ-9 (≥5) at baseline. B. Reports persistent mood symptoms during MINI (e.g., ≥2 weeks of depressive mood/anhedonia, or several days of elevated/irritable mood).
• 4. Owns a smartphone with stable internet connectivity, can operate it without difficulty, and agrees to install a digital phenotyping application, wear a Fitbit device daily, and complete daily mood logs throughout the study period.
• Exclusion Critera (Overall)
• 1. Inability to provide informed consent due to cognitive impairment, severe psychiatric symptoms, or language barriers.
• 2. Presence of any neurological or medical condition that may significantly affect mood, cognition, or behavior (e.g., epilepsy, dementia, traumatic brain injury).
• 3. Current substance use disorder or dependence (excluding nicotine or caffeine) that is either untreated or clinically unstable.
• 4. Severe suicidal ideation or risk as determined by clinical judgment at screening.
• 5. Ongoing participation in another interventional clinical trial, particularly those involving psychotropic medications or digital health interventions.
• 6. Inability or unwillingness to wear a wearable device (Fitbit) or use the required mobile application daily throughout the study.
• 7. Lack of stable internet access or a compatible smartphone required for digital phenotyping data collection.
• 8. Any other condition that, in the investigator's judgment, may compromise the participant's safety, compliance, or the integrity of the study data.