Adult attention-deficit disorder

Adult attention deficit disorder (AADD) is the common terminology for the psychiatric condition currently known as attention-deficit hyperactivity disorder (ADHD), also known as attention deficit disorder (ADD), when it occurs in adulthood. Although the exact prevalence in adults is unknown, epidemiologic studies thus far reveal that the condition, marked by inattentiveness, difficulty getting work done, procrastination, or organization problems, probably exists in about 2-4% of adults. The condition persists to adulthood in about half of children diagnosed with the disorder.

Cause

ADHD was once looked upon as a discipline and behavioral problem resulting from bad parenting. Some suggested it was caused by high sugar intake, food additives, excessive TV viewing, and family problems. But none of these explanations is supported by scientific evidence.

~ ~ ~ ~ ~ ~ ~ ~ ~ ~

Exact cause or causes of ADD are not conclusively known. However, scientific evidence strongly suggests that in many cases the disorder is genetically transmitted and is caused by an imbalance or deficiency in certain chemicals that regulate the efficiency with which the brain controls behavior.

~ ~ ~ ~ ~ ~ ~ ~ ~ ~

A 1990 study at the National Institute of Mental Health correlated ADD with a series of metabolic abnormalities in the brain, providing further evidence that ADD is a neurological disorder. While heredity is often indicated, problems in prenatal development, birth complications, or later neurological damage can contribute to ADD.

Related Topics:
National Institute of Mental Health - Metabolic - Neurological - Heredity - Prenatal

~ ~ ~ ~ ~ ~ ~ ~ ~ ~

The presumed causes under investigation include:

~ ~ ~ ~ ~ ~ ~ ~ ~ ~

• brain differences (brain scan technology has revealed differences in the size, symmetry, metabolism, and chemistry of the brain in those who have ADHD; however, it should be noted that there is yet no clear determination of the source of these differences).
• genetics (children who have one parent with ADHD have a higher incidence of ADHD; current research is examining which genes are involved in ADHD). This investigative path also suggests environmental factors, handed down from generation to generation, that may trigger the symptoms associated with ADD.
• brain development in utero and during the first year of life (possibly related to drug use during pregnancy or environmental toxins).

There is increasing evidence that variants in the gene for the dopamine transporter are related to the development of ADHD (Roman et al., 2004, Am J Pharmacogenomics 4:83-92). This makes sense, as according to other recent studies, people with ADHD usually have abnormally high dopamine transporter levels which reclaim the dopamine emitted by a presynaptic neuron before the postsynaptic neuron can fully make use of it. The stimulant medications used to treat the disorder are all capable of blocking dopamine transporters. Therefore, it is theorized that stimulant medication allows the brain to use its natural supply of dopamine more efficiently by blocking the dopamine transporters. Currently this theory is the most widely accepted in the scientific and medical community.

~ ~ ~ ~ ~ ~ ~ ~ ~ ~

New studies consider the possibility that norepinephrine also plays a role. (see Krause, Dresel, Krause in Psycho 26/2000 p.199ff).

~ ~ ~ ~ ~ ~ ~ ~ ~ ~