One focus of my work is on refining the classification of mental disorders, which involves identify natural clusters of symptoms and charting trajectories of these syndromes over time. Another focus is on applications of artificial intelligence to detect and forecast psychopathology using language, facial expressions, and sensors.  Moreover, I study vulnerabilities to psychopathology including genetics, neural circuits, and personality traits. This work employs methods from advanced quantitative modeling, molecular genetics, and neuroscience. I study these questions in adults, adolescents, and special populations, such as, responders to WTC disaster. Main areas of focus are anxiety and mood disorders, psychotic disorders, and personality problems.