The origins of separation anxiety disorder stem from attachment theory which has roots in the attachment theories of John Bowlby.He found that babies need their mothers, when they were separated from their mothers, they would become anxious even if they were cared by others. At that time, there had a particularly monkey experiment ：Harry Harlow's soft cloth padded fake monkey mother and hard cold iron monkey mother experimen. And his attachment theory also contributed to the thinking process surrounding separation anxiety disorder.
There are 4 main attachment styles according to Bowlby; secure attachment, anxious-avoidant attachment, disorganized attachment, and anxious-ambivalent attachment. Anxious-ambivalent attachment is most relevant here because its description, when an infant feels extreme distress and anxiety when their caregiver is absent and does not feel reassured when they return, is very similar to SAD.
In the 1980, this attachment theory brings into human beings. So, adults will be anxious and afraid when someone separated from them. In addition, the extend of attachment theory will use for analyze of close relationships. In another words, as we grow up, our mother is no longer the one we attach to, but our attachment patterns and habits are applied to courtship relationships and even attachment to work pairs and objects.
In extending to adults, these tags or types changes:
- Secure attachment
- Anxious Attachment (worried that nobody want to be with them)
- Dismissive Avoidant (people are unreliable!)
- Fearful Avoidant (I'm afraid of being hurt!)
People who have separation anxiety may show the following ：
- Sensitive to rejection or abandonment
- Constant need for support and contact from others
- Fear of not being appreciated
- Desire to get closer and more secure with others
- Negative self-perception and value
- Fear of losing a companion
- Sensitive to signals that the partner is feeling distant
- Behaviorally prone to pushing the partner away
- Has a high need for security
- Always feel uncertain about the reliability of the companion
However, in the current U.S. Diagnostic and Statistical Manual of Mental Disorders (DSM-5), this is not listed as a mental illness.