Hyperactivity-impulsivity is one of three types of attention deficit hyperactivity disorder (ADD/ADHD): inattention type, hyperactivity-impulsivity type, and combined type. ADHD is a neurological disorder characterized by a chronic inability to sit still. This disorder can start as early as 3-6 years of age, and some symptoms must be present before age 12 for an accurate diagnosis. Here is a look at the causes of ADHD.
Exactly what causes ADHD (or ADD) remains largely a mystery. Many cognitively based disorders of this nature have their basis in an abnormal structure of the brain. It is possible that there may be issues with the central nervous system during pivotal developmental periods (such as in utero) to result in these abnormalities. It is possible that brain injuries may even impact the development of this disorder.
Exposure to certain things in the environment—mothers who drink or use tobacco, and being born prematurely or underweight—may all have an impact. Environmental exposures may also impact young children sufficiently to induce ADHD. Family history also plays a big role—parents with ADHD are more likely to have children with ADHD than parents who do not have the disorder. Whatever the case, the brains of those with ADHD are different from non-ADHD brains, as evidenced by the types of medication that seem to be effective for treatment and control. While stimulants tend to make “normal” brains behave more like those of someone with ADHD, they actually help improve focus and reduce activity levels for those with ADHD.