what is most common childhood psychiatric disorder
1 The most common childhood mental disorders are anxiety disorders, depression, and attention deficit hyperactivity disorder (ADHD).  Although less common, developmental disorders and psychotic disorders in children can have a lifelong impact on the child and his or her family.
This study, for the first time, shows that there are specific genetic variants that influence a range of childhood and adult-onset psychiatric disorders that we think of as clinically different, said lead researcher Dr. Jordan Smoller, a professor of psychiatry at Harvard Medical School in Boston.