Figure 2
Combinations of RNA measurements have high predictive power, though individual measurements can be non-predictive. The heat maps contain the cross-validated accuracy, specificity, and sensitivity of pairwise combinations of the top five predictive transcripts from backward selection with linear SVMs. Even though AMFR had high predictive value for classifying MDD in conjunction with other variables, it had no predictive power on its own, as demonstrated by a specificity of 0%. Combinations of transcripts can inform a useful SVM boundary even if single transcripts have no ability in isolation, suggesting that depression is associated with combinations of genes. Note that backward selection does not comprehensively explore all transcript combinations and the complex relationships among transcripts suggest that a more predictive combination may still remain. MDD, major depressive disorder; SVM, support vector machine.
