Research has shown that, if left untreated, children with separation anxiety disorder (CSAD) are more likely to perform poorly in school, miss out on important life experiences, and potentially have substance abuse issues. Having some separation anxiety is expected of young children, and usually goes away as a child ages. It's when the child's discomfort while separating becomes excessive, based on the developmental stage of the child.
Anxiety disorders most frequently co-occur with other conditions such as depression, eating disorders, and attention-deficit/hyperactivity disorder (ADHD), delaying treatment can be detrimental to a child's wellbeing. Research estimates that 4% of young kids may have a clinical degree of separation anxiety, and that 36%, will continue in adulthood if not treated early.