It exist all kind of medication to help the brain to focus on one task.
(ADD/ ADHD Drugs)
References :

Hyperactivity can be described as a state in which a person is abnormally easily excitable and exuberant. Strong emotional reactions and a very short span of attention are also typical for a hyperactive person. Some individuals may show these characteristics naturally, as personality differs from person to person. Nonetheless, when hyperactivity starts to become serious and harmful to the person as well as others, it may be classified as a medical disorder. The slang term "hyper" is used to describe someone who is in a hyperactive state.

It is often associated with organic disorders, such as ADHD, and autism and non-organic disorders, such as caffeinism. Some may experience both autism and ADHD.

Causes:

Other Causes of Hyperactivity
There was a great deal of focuson Attention-deficit hyperactivity disorder as a cause of hyperactivity. Other conditions can cause it as well. Normal young children can be very lively and have short attention spans. Normal teenagers can also appear hyperactive; puberty can cause it. Children who are bored, are suffering from mental conflict, or are having problems at home - which may even include sexual abuse - can be hyperactive. The disorder has a large range of affects on children. Some have learning disabilities, while others may be very gifted.

Hyperactivity can also occur because of problems with hearing or vision. Overactive thyroid, lead poisoning, depression, anxiety, and a range of psychiatric illnesses are some of the potential causes.

Hyperactivity is sometimes associated with mania. Another more common cause of hyperactivity is lack of sleep. More severe cases of hyperactivity can be very harmful if left untreated, since hyperactive people seldom think about the consequences of their actions.

Does sugar make one hyperactive?
A common belief is that eating too much sugar will make a person hyperactive. This belief is especially prevalent amongst parents and teachers who claim that children’s behavior often get more rowdy, excited and energetic after they eat too many sugary food and drinks (such as candy or soda). One particular study found that the perception by parents regarding their children’s hyperactivity depended on their belief as to whether they had been given sugar. [1]

Nevertheless, caffeine in the sweets or sugary beverages consumed by children and many other people alike may be linked to hyperactivity….
References :
wikipedia…