Attention deficit hyperactivity disorder (ADHD) is a disorder that may be characterized by a pattern of inattention (inability to concentrate) sometimes combined with hyperactivity-impulsivity that is persistent, developmentally inappropriate, and occurs in at least 2 different settings before the age of 7.
ADHD affects 5% to 12% of school-aged children, occurring more frequently in boys than girls. ADHD may persist into adulthood in many cases. An inability to integrate in social, academic, or work-related settings is a pattern seen in people with a history of ADHD. In childhood, a person with ADHD may have academic problems, as the condition affects a person's ability to concentrate and focus on tasks. Because they are unable to organize their work or pay attention to their studies, children with ADHD may try to distract other children in class.
People with ADHD are especially sensitive to sensory stimuli such as noise, touch, and visual cues. They can easily be overstimulated, leading to changes in behaviour that may include aggressiveness.
Many people think ADHD and ADD (attention deficit disorder) are two different conditions, but they are in fact two names for the same condition. Other names no longer in use are minimal brain dysfunction (MBD) and hyperactivity.