This review presents supporting evidence that early disruptions in mother-infant relationship in primates, including infant maltreatment, are important risk factors for the development of psychopathology and pathophysiology during childhood and adolescence. Current research in this field is trying to identify important aspects of early adverse experiences such as the timing, frequency, duration, "perceived" intensity of the stressful or traumatic events, the role of social support (e.g., nurturing caregiver) in buffering the deleterious outcomes of early adversity, as well as the role of sex and genetic factors on individual variability in vulnerability. The use of nonhuman primate models of early adverse caregiving is helping to put the pieces of the puzzle together to fully understand the causes and consequences of similar experiences in humans. These models are essential to characterize the time course of biobehavioral alterations throughout development, using prospective, longitudinal studies performed under controlled experimental conditions and using invasive approaches that are unrealistic and unethical when studying human populations.