Teens often continue to have the symptoms of attention deficit hyperactivity disorder (ADHD) that began in childhood, although they are expressed differently.

Inattention

This symptom is the most difficult to identify in childhood. The primarily inattentive ADHD subtype may not be recognized at all until a child grows into a teen. Although symptoms of inattentiveness begin during childhood, a child may be able to function fairly normally. Also, family members and other caregivers may be able to help the child to compensate, without realizing the problem might be ADHD. As adolescence approaches, inattentiveness may become pronounced with the new demands from increasing academic workloads and other responsibilities. Problems usually develop that prompt an evaluation for ADHD during major transition points, such as when starting middle school, high school, or even college.

Impulsivity

Because of their impulsivity, teens with ADHD are more likely to engage in risky behaviors, such as reckless driving, having unprotected sex, or using alcohol or drugs.

Hyperactivity

Obvious symptoms of hyperactivity may decrease during the teen years. But they may be replaced by fidgeting or feelings of restlessness.

Other conditions

Children with ADHD may have oppositional defiant disorder (ODD). If a child has ODD, it may lead to conduct disorder during the teen years, especially if ODD is left untreated.