Attachment and Health
John Bowlby and Mary Ainsworth developed attachment theory in the 1960s while investigating the effects of maternal separation on infant development. The development of the Strange Situation task in 1965 by Ainsworth and Wittig allowed researchers to systematically investigate the attachment system operating between children and their parents. The Strange Situation involves separating infant-parent dyads and observing infant behaviours upon reunion. Infant behaviour tended to follow patterns, leading to the development of three attachment categories: Secure, Anxious-Avoidant, and Anxious-Resistant. In 1990, Ainsworth added a new category, championed by Mary Main, called Disorganized/Disoriented attachment, characterized by its less reliable pattern of behaviour.
Marc David Lewis
Through a sabbatical at the University of Oregon in 2000-2001, Lewis took the next step in developing his integrated model by delving into the neural underpinnings of emotion regulation. His current research program tests this model by examining brain and behavior in normal and clinically referred children and assessing neural changes corresponding with successful treatment. His papers on the contribution of dynamic systems theory and affective neuroscience to understanding human development and clinical syndromes have appeared in journals such as "Child Development", "Behavioral and Brain Sciences", "Development and Psychopathology", and "Perspectives on Psychological Science". He has also co-authored two books with his wife, Dr. Isabela Granic. The first is an edited volume of dynamic systems approaches to emotional development. The second is a guide for parents about when to attempt sleep training with toddlers. 
Dr. Lewis' most recent book, "Memoirs of an Addicted Brain", is an account of his addiction to drugs as a young man with accompanying explanations of the neurobiological processes underlying various drug experiences as well as the process of addiction itself.