Correlations between patterns of activity and the response to treatment yield distinct signatures for different antidepressant treatments

Alterations in circadian patterns of activity have been described in several psychiatric disorders, and in major depressive disorder (MDD) have been associated with symptom severity. The aim of this study was to investigate the correlations between activity patterns and the response to different antidepressive treatments. We used actigraphy recordings acquired in three independent clinical trials investigating the response to internet-delivered cognitive behavioral therapy (iCBT), escitalopram, or ketamine, where symptom severity was assessed on MADRS scale. Data processing procedure was designed to extract features describing individual circadian cycles, as well as the average circadian profile for each subject. The analysis of effects of antidepressive treatments on single features (independently from magnitude of response) showed alterations in treatment-specific subsets of features. Further analysis revealed distinct correlations between longitudinal changes in individual features and the response to iCBT, escitalopram, or ketamine. Linear regression ensembles modeling the response to treatment were trained on actigraphy recorded during the depressive episode, before intervention. The analysis of coefficients following Bayesian model averaging showed that better response to iCBT was associated with weaker circadian entrainment; better response to ketamine was associated with more robust circadian entrainment and higher fragmentation of activity patterns; while higher age and steeper propensity to sustain activity was associated with better response to either iCBT or ketamine. Our data suggest that the analysis of circadian patterns of activity can potentially be used for predicting the response to specific MDD treatments, however larger confirmatory studies are required. HighlightsO_LIDifferent antidepressant treatments alter specific subsets of features of activity patterns. C_LIO_LIThe magnitude of response to treatment correlate with changes in patterns of activity. C_LIO_LIPatterns of activity correlate with the response to specific antidepressive treatments. C_LI