Separation anxiety disorder (SAD) is one of the most common childhood anxiety disorders. SAD is an exaggeration of other developmentally typical anxieties manifested as excessive concern, worry, or even fear of actual or expected separation from an attachment figure. Although separation anxiety is a developmentally appropriate phenomenon, the disorder can manifest with inappropriate intensity at the inappropriate age or in the inappropriate setting.

Developmentally appropriate separation anxiety manifests itself between 6 and 12 months of age. This normative or physiological separation anxiety persists until about 3 years of age and, under normal circumstances, abates thereafter.