In this study of 18 female depressed patients and 18 age- and sex-matched control subjects, the authors examined the relationship between nonverbal behavior and treatment outcome with amitriptyline. A behavioral analysis indicated that amitriptyline responders could be differentiated from nonresponders before drug treatment on the basis of discrete nonverbal behaviors. Nonresponders showed a high frequency of body-focused self-adaptors, posture shifts, and pauses and a low frequency of smiles, while responders displayed long speech pauses and long durations of head aversion.