The social and emotional competencies of children -future adults- are built during the first years of life. Attachment is an innate behavioral program of primates and in particular of humans whose objective is to increase the probability of protection and survival of the newborn. Attachment is a gateway to the world, to life, a first contact, which closes around the age of three. This protection system is mainly based on physical proximity and contact between mother and baby. If this process is disturbed, the baby will then develop a set of abnormal reactions and social behaviors. A drama that affects an increasing number of children. Aimed primarily at psychologists, child psychiatrists and psychotherapists, but also at educators and social actors, as well as parents, teachers and host families, this guide attempts to answer from a theoretical and practical perspective some of the questions that intrigue those who work and live day to day with children and adolescents suffering from attachment disorders: Why are more and more children suffering from them? What are the causes of their development and their manifestations in behavior and personality? How to direct the treatment in the different vital stages of the child? What can be done to prevent or attenuate their symptoms? How do the people, groups and organizations that work with these children react? How to develop and maintain a coherent therapeutic attitude and structure in the treatment?