According to Dr. Russell Barkley, ADHD is a spectrum disorder. This means that ADHD symptoms of inattention, impulsiveness, hyperactivity and inability to plan can be more or less severe, and can even change over time or under changing circumstances.
Children's ADHD symptoms can change as the child continues to develop in maturity and becomes more able to make some behavior accommodations for some of the symptoms. Also, stress or other emotional problems can make ADHD symptoms worse. Finally, during adolescence, hormones start to influence behavior and changes in attention problems will probably result. This is one of the reasons why ADHD is such a difficult disorder to treat.
Because of these changes, it is important for parents to keep a log of the severity of attention behaviors over time to help their doctors make effective changes in treatment.