Sleep and Activity Patterns as Transdiagnostic Behavioral Biomarkers in Psychiatry: Initial Insights from the DeeP-DD study

TL;DR

This study explores how wearable actigraphy data on sleep and activity can serve as transdiagnostic behavioral biomarkers for psychiatric symptom severity, showing promising correlations across different time scales and diagnoses.

Contribution

It provides initial evidence that actigraphy-derived sleep and activity features are associated with psychiatric symptoms across multiple disorders and temporal resolutions.

Findings

Later rise times correlate with higher depression and anxiety scores.

Increased physical activity links to lower depression severity.

Associations are consistent across individuals and time scales.

Abstract

Background: Symptom rating scales in psychiatry are limited by reliance on self-report, and lack of predictive power. Actigraphy, a passive wearable-based method for measuring sleep and physical activity, offers objective, high-resolution behavioral data that may better reflect symptom fluctuations, but most studies have focused on narrow diagnostic groups or fixed time windows, limiting clinical translation. Objective: To examine whether actigraphy-derived sleep and activity features correlate with psychiatric symptom severity in a transdiagnostic psychiatric sample, and to identify which features are most clinically relevant across multiple temporal resolutions. Methods: We present a feasibility case series study with preliminary data from eight outpatients enrolled in the DeeP-DD study, a transdiagnostic study of digital phenotyping. Participants wore GENEActiv actigraphy devices and symptom severity was measured using a variety of validated scales. We performed intra-individual Spearman correlations and inter-individual repeated measures correlations across daily, weekly, monthly, and full-duration averages. Results: Intra-individual analyses revealed that later rise times were significantly associated with higher weekly PHQ-9 scores in participant #7 (\r{ho} = 0.74, P=.0003) and participant #4 (\r{ho} = 0.78, P=.022), as well as higher weekly GAD-7 scores in participant #7 (\r{ho} = 0.59, P=.026). Inter-individual analyses showed that weeks with later average rise time correlated with higher PHQ-9 (r = 0.48, P=.0003) and GAD-7 scores (r = 0.38, P=.032). Increased light physical activity was linked to lower PHQ-9 scores weekly (r = -0.44, P=.001) and monthly (r = -0.53, P=.014). Conclusion: Consistent associations between actigraphy features and symptoms across temporal scales and diagnostic groups underscore their potential utility for scalable, real-world clinical monitoring.