Separation anxiety disorder is a psychological condition in which an individual has excessive anxiety regarding separation from home or from people to whom the individual has a strong emotional attachment (like a mother). Present in all age groups, adult separation anxiety disorder (affecting roughly 7% of adults) is more common than childhood separation anxiety disorder (affecting approximately 4% of children). . Separation anxiety disorder is often characterized by some of the following symptoms:
Recurring distress when separated from the subject of attachment (such as the mother or home)
Persistent, excessive worrying about losing the subject of attachment
Persistent, excessive worrying that some event will lead to separation from a major attachment
Excessive fear about being alone without subject of attachment
Persistent reluctance or refusal to go to sleep without being near a major attachment figure, like a mother
Separation Anxiety Disorder should not be confused with Separation Anxiety, which occurs as "a normal stage of development for healthy, secure babies."  Separation anxiety occurs as babies begin to understand their own selfhood - or understand that they are a separate person from their primary caregiver. At the same time, the concept of object permanence emerges - which is when children learn that something still exists when it is not seen or heard. As babies begin to understand that they can be separated from their primary caregiver, they do not understand that their caregiver will return, nor do they have a concept of time. This, in turn, causes a normal and healthy anxious reaction.