Is it hard for your child to sit still?（“坐不住”） Does your child act without thinking first? （行动前欠思考）Does your child start but not finish things?（不专注） If so, your child may have attention deficit hyperactivity disorder (ADHD). Nearly everyone shows some of these behaviors at times, but ADHD lasts more than 6 months and causes problems in school, at home and in social situations.

ADHD is more common in boys than girls. It affects 3-5 percent of all American children （男孩较女孩多见，约有3-5%的美国儿童患“多动症”）.

The main features of ADHD are（多动症的主要特征如下）

• Inattention （注意力难集中，不认真听讲或难专心于某一件事）
• Hyperactivity （反应过渡，多动）
• Impulsivity （冲动，行动缺乏思考）

No one knows exactly what causes ADHD. It sometimes runs in families, so genetics may be a factor. There may also be environmental factors.

A complete evaluation by a trained professional is the only way to know for sure if your child has ADHD. Treatment may include medicine to control symptoms, therapy, or both. Structure at home and at school is important. Parent training may also help.

NIH: National Institute of Mental Health