This document provides an overview of attachment theory, including definitions of secure, avoidant, ambivalent, and disorganized attachment styles in children. It discusses John Bowlby and Mary Ainsworth's seminal research in this area. Secure attachment develops when a child believes their caregiver is available and responsive to their needs. Insecure styles develop when caregivers are inconsistent, neglectful or abusive. Disorganized attachment occurs when the caregiver is both the source of fear and comfort. Long term effects of insecure attachment can include difficulties with relationships and regulating emotions. Treatment focuses on providing consistent safety, trust and support to help "reparent" children and repair their ability to form attachments.