Animal Models of Attention-Deficit Hyperkinetic Disorder (ADHD)

Abstract

ADHD (attention-deficit hyperkinetic disorder) is a common childhood-onset neuropsychiatric disorder characterized by attention deficit, hyperactivity, and impulsiveness, which employs to both children and adults. ADHD is a behavioral disorder and believed to affect 1 in 20 children in the USA, 3–7% of school-aged children, and persists in 30–50% of adults. ADHD was first illustrated 100 years ago as a childhood disorder, which affects boys more often than girls. In the 1930s and l940s, children with the ADHD were called “brain damaged” or “brain injured” because their behaviors were identical with persons having brain damage. In the 1960s “hyperactive” or “hyperkinetic” became the term of choice for describing ADHD children, and in the year 1980s, the disorder was renamed to “attention deficit disorder” (ADD). This disorder was mainly divided into two types: with hyperactivity (ADD + H) and without hyperactivity (ADD-H). The first example of a disorder that appears to be related to ADHD was given by Sir Alexander Crichton in 1798. Children diagnosed with ADHD without exhibiting any signs of hyperactivity had eight of the inattention and impulsivity characteristics. In 1955, FDA approved methylphenidate (Ritalin) for the treatment of hyperactivity disorder. In 1987, DSM-III-R (revised) changed “attention deficit disorder” to “attention deficit hyperactivity disorder” (ADHD) and it accounts 14 symptoms, in which any eight symptoms were sufficient for diagnosis of ADHD.