This guide offers assessment and intervention guidelines for the Connecticut Birth to Three system concerning the emotional and psychological well-being of infants and toddlers in the system. Emphasis is on infants and toddlers who exhibit symptoms of traumatic stress disorder, depression or other affective disorders, regulatory disorders, sleep and eating disorders, and disorders of relating and communicating. Guidelines address the definition of infant mental health; stages of social and emotional development (from birth to 8 months, from 9 to 16 months, and from 16 to 36 months); integrated approaches to healthy emotional and social development; assessment, including recommended areas for assessment and diagnostic guidelines for infant mental health; and services and resources including those available to all families in the Birth to Three system, services for children with identified mental health needs, and other family programs and support services. Training needs for early interventionists are also identified. Appendices include the Birth to Three System mission statement, statements from the Connecticut Progress Council and the Connecticut Department of Education, a list of instruments useful in examining social and emotional development, a list of agencies and services in Connecticut to help families of children with emotional and behavioral disorders, and an outline of training outcomes and content. Contains 22 references. (DB)