Attention deficit hyperactivity disorder (ADHD) is a common childhood disorder characterized by difficulties maintaining focus, controlling behavior, and hyperactivity (over-activity). Although many children experience some of these difficulties with attention and over-activity, these symptoms are much more severe and impairing in children with ADHD. Symptoms of ADHD can appear as early as 3 years of age, and can cause significant challenges both in the home and school setting.
ADHD is caused by multiple factors including genetic and environmental influences. Variations in genes can influence the development of ADHD. Brain injury can also cause the onset of ADHD, but is a rare occurrence.
Three behaviors used to categorize the symptoms of ADHD are inattention, hyperactivity, and impulsivity. Inattention refers to being easily distracted or having issues focusing on one task or item. Inattention can cause problems with focusing on planning and completing tasks, following instructions, and with processing information. Hyperactivity is indicated by being overly physically active, being fidgety, and talking or making noises a lot. Impulsivity is shown by an inability to be patient for long periods of time, acting without contemplating consequences, expressing emotions in inappropriate ways or times.