What is mental health in infancy and early childhood? Why is it important? How does the infant-parent relationship influence development, and how do these early experiences shape our lives? How can clinical assessment and intervention focus on these early relationships to improve developmental outcomes for infants, young children, and their families? This thoroughly updated and expanded second edition provides an evidence-based and practical approach to assessment of young children and their families across diverse settings. The impact of attachment issues, prematurity, trauma, parental mental illness, substance abuse, and other adverse circumstances is clearly explained. Additionally, the quality of parenting and the importance of early relationships are addressed. Written for a wide range of professionals - including maternal and child health nurses, general practitioners, psychiatrists, child protection workers, early childhood educators, and community and mental health workers - this edition has two new chapters on intervention and professional issues, such as training, ethics, and advocacy. The growing understanding of factors that influence infant psychological development, and influence the social and emotional well-being of young children and their families, make this book an essential reference for all health care practitioners and early childhood professionals.