A brain condition can be tracked based on identification of co-activation of two antagonistic networks of a patient's brain. Various embodiments concerns methods and devices for sensing one or more signals indicative of brain activity, detecting one or more episodes of default mode network activation based on the one or more signals, detecting one or more episodes of salience network activation based on the one or more signals, and identifying one or more episodes of temporal co-activation of the default mode network and the salience network based on the detected one or more episodes of default mode network activation and the one or more episodes of salience network activation. The brain condition can be tracked and treated based on the identification of the one or more episodes of co-activation.