There has been a marked increase in research aimed at studying dynamic (e.g., day-to-day, moment-to-moment) changes in mental disorders and related behavior problems. Indeed, the number of scientific papers published that focus on real-time monitoring has been nearly doubling every five years for the past several decades. These methods allow for a more fine-grained description of phenomena of interest as well as for real-world tests of theoretical models of human behavior. Here we comment on the recent study by van Winkel and colleagues (this issue)as an excellent example of the use of real-time monitoring methods to better understand mental disorders. We also discuss the expanding universe of new technologies (e.g., smartphones, wearable biosensors) that can be used to make discoveries about psychopathology and related constructs and describe what we perceive to be some of the most exciting scientific possibilities that can be achieved in the near term by taking advantage of these new and rapidly developing tools.