["Family Relations, Volume 75, Issue 2, Page 1158-1175, April 2026. ", "\nAbstract\n\nBackground\nLimited attention has been given to conceptualizing and examining what can help parents of adult children with mental illness recover from the impact of the illness on their relationship with their adult child. The concept of differentiation can serve as a means of exploring their recovery.\n\n\nObjectives\nTo examine changes in the parents' differentiation with the adult child and how differentiation occurred.\n\n\nMethod\nPersonal interviews were conducted with 10 parents who are members of an association for family members of individuals with mental illness in Israel. A thematic analysis method was used.\n\n\nResults\nAfter the onset of the mental illness, the parents experienced negative emotions and a process of mourning, and they struggled with emotional regulation. Over the years, the relationships with the adult child changed due to emotional and perceptual shifts regarding the mental illness and by learning how to adjust their interactions.\n\n\nConclusions\nThe concept of differentiation can help assess the challenges parents face and focus on intrapersonal and interpersonal change‐promoting processes in the relationship with the adult child.\n\n\nImplications\nInterventions should help parents overcome challenges after the illness begins and in developing differentiation in the relationship with the adult child to advance their recovery.\n\n"]