Millions of children and adolescents suffer from attention-deficit/hyperactivity disorder (ADHD). In many cases, the causes of ADHD in adolescence are unknown. There are few external factors that may contribute to ADHD, such as exposure to toxins, both in utero and as a child. Some types of food additives may also cause ADHD in adolescence, and genes may also play a role. In very rare cases, an injury to the brain can be the cause of the condition.
Adolescents and children with ADHD may have trouble focusing in the classroom or completing homework. The condition may make it difficult for a person to pay attention to instructions or to complete a task as asked. ADHD patients often seem distracted or forgetful.
Environmental factors may play a role in developing ADHD in adolescence. Lead exposure is connected to a high risk of ADHD as well as for violent behavior. Children can be exposed to lead through paint in older buildings as well as through older water pipes and contaminated toys.
A mother's behavior during pregnancy can impact her child in adolescence. Mothers who smoke, drink alcohol, or take drugs while pregnant increase the chances of giving birth to a child with ADHD. The drugs reduce neuron activity, which in turn reduces the production of neurotransmitters. Exposure to environmental toxins during pregnancy also increases the risk of ADHD in the child.
In some cases, ADHD in adolescence may be connected to the consumption of certain food additives. There have been noted links between eating foods with added dyes and an increase in hyperactivity. Certain preservatives may also have an effect. Even though sugar is commonly thought to cause hyperactive behavior, studies have not shown a connection.
ADHD appears to run in families and may be caused by a genetic factor. Scientists have identified a few genes that may contribute to ADHD, and studies are in progress to learn more about these genes. ADHD in adolescence may also be caused by an injury to the brain. Brain injuries are very rare, though, and only small number of ADHD patients have suffered such an injury. While an injury is rare, some patients do have differently shaped brain structures than people who do not have ADHD. In some cases, the brain may function differently in patients with ADHD than people without ADHD. For example, there is commonly less brain activity in the areas that control activity in adolescences with ADHD.