Changes in sleep, activity patterns hint at depression relapse

Greater sleep irregularity and lower daily amplitude of activity rhythms appear to be associated with relapse in major depressive disorder (MDD), according to a study.

The observational cohort study included 93 adults (mean age 39.1 years, 62 percent female) with MDD who had responded to treatment for their most recent MDD, with a Montgomery-Åsberg Depression Rating Scale (MADRS) score of ≤14 at baseline. These participants contributed approximately 32,000 complete actigraphy days’ worth of data (median 46 weeks).

The primary outcome was relapse, defined as any of the following: MADRS score of ≥22 for 2 consecutive weeks, psychiatric hospitalization, emergence of suicidal intent or behaviour, or antidepressant treatment escalation. Continuous actigraphy data were averaged every 2 weeks.

Of the participants, 23 had a relapse. Relapse was associated with lower sleep regularity (hazard ratio [HR], 0.46, 95 percent confidence interval [CI], 0.28-–0.74; p=0.002), lower relative amplitude (HR, 0.45, 95 percent CI, 0.29–0.70; p<0.001), lower sleep efficiency (HR, 0.57, 95 percent CI, 0.38–0.85; p=0.005), higher wake after sleep onset (HR, 1.77, 95 percent CI, 1.12–2.80; p=0.01), and higher nighttime activity (HR, 1.86, 95 percent CI, 1.32–2.62; p<0.001).

In time-varying models, relapse was associated with greater composite phase deviation (HR, 1.76, 95 percent CI, 1.04–2.98; p=0.04) and lower relative amplitude (HR, 0.45, 95 percent CI, 0.21–0.97; p=0.046). The association with relative amplitude persisted even after adjusting for concurrent MADRS scores (HR, 0.60, 95 percent CI, 0.36–0.98; p=0.04).

Actigraphy significantly distinguished participants experiencing relapse from those with an ultrastable (MADRS score <14 throughout) and unstable (transient MADRS score, 14-22 without relapse) clinical course.

The findings support actigraphy as a potential scalable biomarker to identify high-risk individuals and facilitate timely, personalized relapse prevention in MDD.