Separation anxiety disorder (SAD), is an anxiety disorder in which an individual experiences excessive anxiety regarding separation from home or from people to whom the individual has a strong emotional attachment (e.g., a parent, caregiver, significant other or siblings). One of our most popular member posts was written by a fellow named Joseph who wrote in to Anxiety Connection to ask for help and support for what he deemed as "adult separation anxiety." Joseph’s inquiry elicited 42 responses from other me. The essential feature of separation anxiety disorder is excessive anxiety concerning separation by a child from the home or from those (in adolescents and adults) to whom the person is attached. This anxiety is beyond that which is expected for the individual’s developmental level. The fear.