Fig. 2

Performance comparison. a, b Accuracy (black disks), specificity (blue diamonds), and sensitivity (red squares) as a function of tree depth [in (a) for basic decision trees and in (b) for gradient-boosted trees]. Dashed lines in panels (a) and (b) represent the corresponding performance indicators of a classifier that is based on the HAMD score at intake and logistic regression, respectively. The training and test datasets consist of 380 and 163 samples, respectively. Markers in panels (a, b) indicate mean values that have been obtained using 1000 cross-validation realizations. Error bars indicate the corresponding standard errors. c–f Distributions of accuracy, specificity, and sensitivity for different classifiers