Adoption Related Issues in Teens
Regarding adoption, normally adoptive parents are not prepared for all the emotional and behavioral issues that are typically experienced with "adoption." Most people view adoption as a process with a childless couple that is unable to have children or have chosen to adopt rather than have biological children. The typical notion of adoption is a couple adopting a "newborn." But this is not the typical case. Many adoptions involve families with biological children, and the adopted child is not a newborn. 
All to often adopted parents are not trained or equipped to deal with all the emotional issues and behavioral problems that are typical of adopted children. In many cases, its "on the job training" and the "training" comes during the crisis involved with the emotional and behavioral problems.
Parents of adopted children face specific challenges, many different challenges from those experienced through biological children. The truth is that adopted children, even those who feel positive about their adoption, experience a variety of unsettling emotions as they become adolescents.
Adoption Creates Anxiety and other intense emotions that are unique
Adopted children often question their identity. They struggle with self-worth. Many adopted children have low self-esteem and unknowingly struggle with perceived grief and loss. Many adopted children can work through their emotions as adolescents, either working things out with parents, counselors, or even peers. However, some adolescents and parents need professional help to deal with the detrimental emotions that create behavioral problems.
Adoptive parenting is much different from biological parenting. The issues are complex, and unless the parent is an adopted child, they struggle to understand why their adopted child is struggling. It is important for parents to keep the lines of communication open with their adopted children. Expect the adopted teens will have unique issues to face as they mature into adults.