Fig. 2: Identification and performance of SDC.

a, ROC curves of the LFP classifier in classifying ‘sick’ and ‘stable response’ states with leave-one-participant-out cross-validation. Grey lines indicate the ROC curve of individual folds of the cross-validation. Black line indicates the mean ROC curve. b, Simultaneous change in spectral features that capture the difference between the ‘sick’ and ‘stable response’ states as reflected by the SDC. The + symbol indicates the top five discriminative features. Gamma* indicates the 30–40 Hz band, as described in the text. c, Change in left-low beta and left-high beta power from the beginning to the end of the observation phase (relative to last week of postsurgical period without stimulation). *P = 0.031 (one-sided Wilcoxon signed-rank test). d, Trajectory of the SDC over 24 weeks. Grey lines indicate individual participants and the black line indicates the average of the five typical responders. Error bars indicate standard deviation (n = 5 participants). e, Illustration of identifying state change from ‘sick’ to ‘stable response’. Transition to ‘stable response’ is defined as the week when the measure falls below the transition threshold for two consecutive weeks and (during the observation period) never returns above threshold for two or more weeks. f, State change from ‘sick’ to ‘stable response’ in an exemplar participant (P002). The blue line indicates the state inferred from HDRS-17 scores and the red line indicates the state inferred from the SDC. g, ROC curves of the SDC state predicting the HDRS state. Grey lines indicate the ROC curve for individual participants and the black line indicates the mean ROC curve.