This lecture describes an attachment-based model for understanding the psychological and family processes surrounding what has traditionally been referred to as “parental alienation” in high-conflict divorce. The presentation will cover the family systems origins, the contributing personality disorder factors, and the attachment-system foundations that lead to parental alienation following divorce. A set of three diagnostic indicators in the child’s symptom display will be identified that can reliably identify the presence or absence of parental alienation as the cause of the child’s rejection of a relationship with a parent.