Nobody really knows the exact cause of attention deficit disorder/attention deficit hyperactivity disorder (ADD/ADHD). However, certain factors have been identified as possibly causing or contributing to the development of ADD/ADHD.
Genetic factors
Several genes are associated with the development of ADD/ADHD. Studies have shown that the genes responsible for certain brain functions related to attention and concentration can be abnormal in people with ADD/ADHD.
Having blood relatives with ADD/ADHD may increase your risk for developing the condition. Siblings of a person with ADD/ADHD have twice the risk of having the condition themselves as compared to those with normal siblings. The risk is even higher if you have an identical twin with ADD/ADHD.
A person with ADD/ADHD is likely to have children who will also have the disorder. If both parents have ADD/ADHD, the risk for having children with the same condition is even higher.
Factors affecting brain development
The development of a person’s brain begins even before birth. It is important for the developing brain to receive an adequate supply of blood, oxygen, and nutrients in order to form and function properly. Certain conditions can affect the growth and development of a baby’s brain even before birth. Any of the following during pregnancy may increase the risk of having a child with ADD/ADHD:
- l Smoking cigarettes or drinking alcohol
- l Being exposed to toxins
- l Having a difficult pregnancy (bleeding, severe morning sickness, hypertension or diabetes during pregnancy, or other conditions)
- l Being exposed to infectious diseases. Many children with ADD/ADHD are born during September. Experts believe this is because their mother were exposed to many winter illnesses during the first trimester of pregnancy.
- l Having a difficult labor
Being born prematurely is also a possible contributing factor to developing ADD/ADHD. Babies with low birth weight are also at increased risk. Conditions that can affect the brain, such as inflammation, infection, or trauma, may also increase the risk for developing ADD/ADHD if these happen early in an infant’s life.
Toxins in the environment, such as lead, may also injure a child’s growing brain. This may possibly contribute to the development of ADD/ADHD.
Factors affecting brain function
Certain parts of the brain are responsible for concentration, attention, and controlling behavior. Chemicals called neurotransmitters help regulate these functions.
The frontal lobe is the area mainly responsible for planning and appropriately timing your actions. This area of the brain also contributes to the control of your impulses. People with ADD/ADHD show decreased activity in this area of the brain, especially when they are asked for an appropriate response. This may explain the symptoms of impulsivity present in people with ADD/ADHD.
Other areas of the brain, such as the limbic system, are in charge of attention and concentration. There are also parts of the brain, such as the cerebellum, that coordinate movement and activity. People with ADD/ADHD have a lack of function in these areas as well.
Two important neurotransmitters are thought to be related to ADD/ADHD. These are norepinephrine and dopamine. It has been shown that drugs that increase the levels and activity of norpeinephrine in the brain are helpful in treating people with ADD/ADHD.
Studies have shown that decreased dopamine activity in the brain is linked to symptoms of inattention. Medicines that increase dopamine activity relieve these symptoms. Other chemicals, such as cocaine, nicotine, and other drugs of abuse, can also increase dopamine activity for short periods of time. This may be a possible reason as to why people with ADD/ADHD tend to also smoke heavily or abuse drugs.
Social and emotional factors
Children in institutions, such as orphanages, have been shown to have symptoms of hyperactivity and inattention. These symptoms are thought to be a result of emotional deprivation. When these children are placed in an emotionally healthy environment, such as being adopted into a family, the symptoms decrease or even disappear.
Stressful emotional events may contribute to the development of ADD/ADHD. They may also make the condition worse if it is already present. Emotional trauma and disruptions in family life such as separation or divorce of parents are some examples of these events.
Factors that do not cause ADD/ADHD
There are many popular theories about other things that cause or contribute to the development of ADD/ADHD. However, many of these “factors” have not been scientifically proven to have any link to ADD/ADHD at all.
It was previously thought that watching too much television, especially early in a child’s life, could lead to ADD/ADHD. Newer studies have come out, however, showing that TV does not contribute to symptoms of inattention. Of course, it is always a good idea to limit a child’s TV viewing time and encourage them to engage in other physical activities, such as playing outside.
Too much sugar in a child’s diet does not cause ADD/ADHD. Sugar can cause a child to become more active, as sugar quickly provides an energy boost to the body. However, sugar does not lead to the actual development of ADD/ADHD. However, like with TV viewing, it is healthier to limit a child’s consumption of processed, refined sugar. It is part of a healthy, balanced diet to consume less sweets and more fruits, vegetables, and complex carbohydrates.