Infant and toddler mental health is a growing area of interest for psychiatrists, child psychologists, pediatricians, and educators. Expanding research in this area highlights the need for early identification and assessment of mental health problems and risk factors in infants and toddlers. In addition, public policy and recent legislation have offered new opportunities to provide services to infants and toddlers who are at risk or are already exhibiting delays or deviance in social and emotional functioning. This handbook is the first of its kind to bring together the several new diagnostic and assessment approaches for working with infant and toddler mental health.