Life Changes

• According to HealthSquare.com, separation anxiety disorder can be triggered in people, especially children, who have experienced a major life change, whether it be a good change or a bad change. Some examples of life changes include moving, changing schools or divorce.
  
  

Chemical Imbalance

• According to the University of Virginia Medical Center, a cause of separation anxiety may involve two chemicals, norepinephrine and serotonin, in the brain that are imbalanced.
  
  

Genetics

• One cause of separation anxiety may simply be genetics, according to the University of Virginia Medical Center. A person suffering from separation anxiety disorder may have inherited a biological tendency to be anxious.
  
  

Traumatic Experience

• Separation anxiety disorder may be triggered in an individual by a traumatic life event. Death of a loved one or hospitalization are examples of traumatic experiences, according to HealthSquare.com.
  
  

Personality Traits

• People who tend to have anxious, shy or fearful personalities are the most common candidates to have separation anxiety disorder, according to HealthSquare.com.