An observational study in Mood Disorders, Major Depressive Diorder and Bipolar Disorders, sponsored by Korea University Anam Hospital. Not yet recruiting. Open to participants aged 19 Years to 75 Years, including healthy volunteers. Per ClinicalTrials.gov, last updated 2026-10-29.
Sponsored by Korea University Anam Hospital · Observational
This single-site prospective observational study aims to validate wearable-derived circadian and behavioral rhythm biomarkers using continuous core body temperature and raw accelerometry measurements and to explore longitudinal changes in circadian and rest-activity rhythms in psychiatric inpatients.
The study consists of two complementary substudies. Study 1 will enroll 150 outpatients and community participants, including 75 patients with major depressive disorder or bipolar I/II disorder and 75 healthy controls. Participants will simultaneously wear a CALERAResearch core body temperature sensor and a Fitbit Charge 6 for approximately 7 days. Agreement between Fitbit-derived circadian and sleep/activity rhythm features and CALERAResearch-derived core body temperature and raw accelerometry markers will be evaluated. A subset of 50 participants will undergo a second measurement at least 1 month later to assess test-retest reliability.
Study 2 will enroll 50 psychiatric inpatients irrespective of final diagnosis. Participants will continuously wear CALERAResearch and Fitbit devices from shortly after admission through the inpatient observation period, with CALERAResearch sensors replaced approximately every 5-7 days. Longitudinal changes in core body temperature rhythms, rest-activity rhythms, and physiological-behavioral rhythm alignment will be examined in relation to changes in psychiatric symptoms.
The study is a single-site prospective observational study conducted at Korea University Anam Hospital and consists of two complementary substudies using wearable core body temperature and wrist-worn sensor data.
Study 1 is a validation study designed to evaluate the agreement between circadian and behavioral rhythm features derived from a consumer wrist-worn wearable device (Fitbit Charge 6) and physiological circadian and high-resolution behavioral rhythm markers derived from CALERAResearch. Seventy-five outpatients with DSM-5 major depressive disorder, bipolar I disorder, or bipolar II disorder and 75 healthy control participants will simultaneously wear both devices for approximately 7 days. The primary physiological circadian phase marker is the midpoint of the core body temperature trough. Fitbit-derived circadian phase, sleep, and activity rhythm features will be compared with core body temperature and raw accelerometry-derived measures. A subset of 50 participants will repeat the measurement after an interval of at least 1 month to evaluate test-retest reliability.
Study 2 is a transdiagnostic longitudinal observational study of 50 patients admitted to the psychiatric inpatient unit. Eligibility does not depend on a specific final psychiatric diagnosis. Participants will undergo repeated measurement of core body temperature, raw accelerometry, and Fitbit-derived sleep and activity measures from shortly after admission through the inpatient observation period. CALERAResearch sensors will generally be replaced every 5-7 days. Psychiatric symptoms will be repeatedly assessed using the Montgomery-Åsberg Depression Rating Scale, Young Mania Rating Scale, Brief Psychiatric Rating Scale, and Clinical Global Impression. The study will evaluate within-subject changes in circadian and rest-activity rhythms and physiological-behavioral rhythm alignment in relation to changes in psychiatric symptom severity and clinical course.
No therapeutic intervention is assigned as part of the study, and no randomization or masking is performed.
1,683 studies on the registry are indexed under Bipolar Disorder; 266 are open to participants now.
This study's planned enrollment of 200 is above the median of 159 across 348 observational studies indexed under Bipolar Disorder.
Browse Bipolar Disorder studies →Korea University Anam Hospital is the lead sponsor of 112 studies on the registry; 31 are open to participants now.
Compared within Bipolar Disorder, this study's primary condition as ClinicalTrials.gg classifies it; the registry's first condition term is Mood Disorders. The counts are of registry records indexed under each term, refreshed daily. How we classify →
This study will enroll 200 adults aged 19-75 years at Korea University Anam Hospital. Study 1 will include 75 outpatients with major depressive disorder, bipolar I disorder, or bipolar II disorder and 75 healthy control participants without a history of psychiatric diagnosis or treatment and without a major mood disorder identified on structured diagnostic assessment. Participants in Study 1 will undergo concurrent monitoring with CALERAResearch and Fitbit devices for approximately 7 days, and a subset of 50 participants will undergo repeat monitoring after an interval of at least 1 month. Study 2 will include 50 patients admitted to the psychiatric inpatient unit for psychiatric treatment, regardless of final psychiatric diagnosis at the time of enrollment. These participants will undergo repeated wearable monitoring during the inpatient observation period.
Inclusion Criteria Study 1 - Outpatient mood disorder group
Study 1 - Healthy control group
Study 2 - Psychiatric inpatient group
Exclusion Criteria Study 1 - Outpatient mood disorder group
Study 1 - Healthy control group
Study 2 - Psychiatric inpatient group
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
The American Psychiatric Association’s manual of mental health diagnoses. DSM-5 (2013, revised as DSM-5-TR in 2022) replaced DSM-IV, and some studies still name the older edition. “Meets DSM criteria for …” means diagnosed by that edition’s diagnostic criteria, usually by a clinician in an interview.
Judged by the study doctor to matter for your health or for the study. It is a doctor’s decision, so ask the study team if you are unsure whether something counts.
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
DSM diagnostic criteria
The American Psychiatric Association’s manual of mental health diagnoses. DSM-5 (2013, revised as DSM-5-TR in 2022) replaced DSM-IV, and some studies still name the older edition. “Meets DSM criteria for …” means diagnosed by that edition’s diagnostic criteria, usually by a clinician in an interview.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Clinically significant
Judged by the study doctor to matter for your health or for the study. It is a doctor’s decision, so ask the study team if you are unsure whether something counts.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Informed consent
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Adults aged 19-75 years with DSM-5 major depressive disorder, bipolar I disorder, or bipolar II disorder. Participants will simultaneously wear CALERAResearch and Fitbit Charge 6 devices for approximately 7 days for validation of circadian and behavioral rhythm biomarkers. A subset may undergo repeat measurement after at least 1 month.
Adults aged 19-75 years with no history of psychiatric diagnosis or treatment and no major mood disorder identified on structured diagnostic assessment. Participants will simultaneously wear CALERAResearch and Fitbit Charge 6 devices for approximately 7 days. A subset may undergo repeat measurement after at least 1 month.
Adults aged 19-75 years admitted to the psychiatric inpatient unit for psychiatric treatment. Enrollment is transdiagnostic and does not require a specific final diagnosis at study entry. Participants will undergo repeated CALERAResearch and Fitbit monitoring during the inpatient observation period.
Circular Correlation Between Fitbit Sleep-Derived eDLMO and CALERAResearch-Derived CBT Trough Midpoint
The relationship between estimated dim light melatonin onset (eDLMO), derived from sleep timing data collected using Fitbit Charge 6, and the core body temperature (CBT) trough midpoint measured using CALERAResearch will be evaluated in Study 1 participants. One circadian phase estimate will be derived for each marker during the 7-day monitoring period. The relationship between the two phase markers will be quantified using the circular-circular correlation coefficient (r), accounting for the 24-hour periodicity of clock time. The coefficient is dimensionless and ranges from -1 to 1, with values closer to 1 indicating stronger positive circular correlation.
Time frame: Day 1 through Day 7
Circular Correlation Between Fitbit Heart Rate Cosinor Phase and CALERAResearch-Derived CBT Trough Midpoint
The relationship between the acrophase estimated from 24-hour cosinor fitting of heart rate data collected using Fitbit Charge 6 and the core body temperature (CBT) trough midpoint measured using CALERAResearch will be evaluated in Study 1 participants. One phase estimate will be derived for each marker during the 7-day monitoring period. The relationship between the two phase markers will be quantified using the circular-circular correlation coefficient (r), accounting for the 24-hour periodicity of clock time. The coefficient is dimensionless and ranges from -1 to 1, with values closer to 1 indicating stronger positive circular correlation.
Time frame: Day 1 through Day 7
Mean Absolute Difference in Phase Changes Between Fitbit Sleep-Derived eDLMO and CALERAResearch-Derived CBT Trough Midpoint
Agreement in circadian phase changes between Fitbit sleep-derived estimated dim light melatonin onset (eDLMO) and CALERAResearch-derived core body temperature (CBT) trough midpoint will be evaluated in 50 Study 1 participants undergoing repeat monitoring. For each marker, the signed circular phase change between the first and second monitoring periods will be calculated. Agreement will be quantified as the mean absolute circular difference between these phase changes, expressed in hours. Lower values indicate closer agreement in the direction and magnitude of phase changes, independent of systematic differences in absolute phase timing.
Time frame: First 7-day monitoring period (Days 1-7) and second 7-day monitoring period (an average of 3 months after baseline)
Mean Absolute Difference in Phase Changes Between Fitbit Heart Rate Cosinor Phase and CALERAResearch-Derived CBT Trough Midpoint
Agreement in circadian phase changes between the acrophase derived from 24-hour cosinor fitting of Fitbit Charge 6 heart rate data and the CALERAResearch-derived core body temperature (CBT) trough midpoint will be evaluated in 50 Study 1 participants undergoing repeat monitoring. For each marker, the signed circular phase change between the two monitoring periods will be calculated. Agreement will be quantified as the mean absolute circular difference between these phase changes, expressed in hours. Lower values indicate closer agreement in the direction and magnitude of phase changes, independent of systematic differences in absolute phase timing.
Time frame: First 7-day monitoring period (Days 1-7) and second 7-day monitoring period (an average of 3 months after baseline)
Mean Absolute Difference in Sleep Midpoint Between Fitbit Charge 6 and CALERAResearch
Agreement between sleep midpoint derived from Fitbit Charge 6 sleep data and rest/sleep midpoint estimated from CALERAResearch raw accelerometry will be evaluated during concurrent monitoring in Study 1. The mean absolute circular difference between corresponding midpoint estimates will be calculated and reported in hours. Lower values indicate closer agreement between devices.
Time frame: Day 1 through Day 7
Rate of Longitudinal Change in CALERAResearch-Derived Core Body Temperature Trough Midpoint
Core body temperature (CBT) trough midpoint will be derived from continuous CALERAResearch measurements during successive monitoring periods in the inpatient cohort (Study 2). Signed circular phase changes will be calculated while accounting for the 24-hour periodicity of clock time. A longitudinal repeated-measures model will estimate the rate of phase change in relation to days since admission, accounting for within-participant correlation. The outcome will be reported as the estimated phase change per day, expressed in hours/day.
Time frame: From study enrollment through study completion, an average of 3 weeks
Rate of Longitudinal Change in CALERAResearch-Derived Core Body Temperature Rhythm Amplitude
Core body temperature (CBT) rhythm amplitude will be derived from continuous CALERAResearch measurements during successive monitoring periods in the inpatient cohort (Study 2). A linear mixed-effects model will estimate the longitudinal rate of change in CBT rhythm amplitude as a function of days since admission, accounting for repeated observations within participants. The outcome will be reported as the regression coefficient, expressed in degrees Celsius per day (°C/day).
Time frame: From study enrollment through study completion, an average of 3 weeks
Rate of Longitudinal Change in CALERAResearch-Derived Rest-Activity Rhythm Interdaily Stability
Interdaily stability (IS) of rest-activity rhythms will be calculated from CALERAResearch raw accelerometry during successive monitoring periods in the inpatient cohort (Study 2). IS is a dimensionless nonparametric measure of the regularity of rest-activity patterns across days, with higher values indicating greater day-to-day rhythm stability. A linear mixed-effects model will estimate the longitudinal rate of change in IS as a function of days since admission, accounting for repeated observations within participants. The outcome will be reported as the regression coefficient, expressed in IS units per day.
Time frame: From study enrollment through study completion, an average of 3 weeks
Rate of Longitudinal Change in Absolute CBT-to-Rest/Sleep Phase Difference
The physiological-behavioral phase difference will be defined as the absolute circular time difference between the core body temperature (CBT) trough midpoint derived from CALERAResearch temperature recordings and the rest/sleep midpoint derived from CALERAResearch raw accelerometry. The phase difference will be calculated for successive monitoring periods in the inpatient cohort (Study 2) and expressed in hours. A linear mixed-effects model will estimate its rate of change as a function of days since admission, accounting for repeated observations within participants. The outcome will be reported as the regression coefficient, expressed in hours/day.
Time frame: From study enrollment through study completion, an average of 3 weeks
Within-Participant Regression Coefficient for BPRS Total Score and CBT-to-Rest/Sleep Phase Difference
General psychiatric symptom severity will be assessed using the Brief Psychiatric Rating Scale (BPRS) total score at baseline and subsequent clinical assessments in the inpatient cohort (Study 2), with higher scores indicating greater psychiatric symptom severity. The physiological-behavioral phase difference will be quantified as the absolute circular time difference, expressed in hours, between the CALERAResearch-derived CBT trough midpoint and raw accelerometry-derived rest/sleep midpoint during the corresponding monitoring periods. A linear mixed-effects model will estimate the within-participant association between phase difference and BPRS total score, separating within-participant from between-participant differences. The outcome will be reported as the within-participant regression coefficient, expressed in BPRS points per hour of phase difference.
Time frame: From study enrollment through study completion, an average of 3 weeks
Between-Group Difference in CBT-to-Rest/Sleep Phase Angle Between Mood Disorder Patients and Healthy Controls
The physiological-behavioral phase angle will be defined as the signed circular time difference between the core body temperature (CBT) trough midpoint derived from CALERAResearch temperature measurements and the rest/sleep midpoint derived from CALERAResearch raw accelerometry. One phase-angle estimate will be obtained for each Study 1 participant during the 7-day monitoring period. The outcome will be reported as the signed circular difference between the mean phase angles of participants with mood disorders and healthy controls, expressed in hours. A value of zero indicates no difference in mean phase angle between groups.
Time frame: Day 1 through Day 7
No study locations are listed for this record.
Plan to share: No
From the registry record's own update history. This site started tracking changes on Sep 25, 2026; for anything earlier, see the record history on ClinicalTrials.gov ↗
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