Predisposing Factors for Attention Deficit Hyperactivity Disorder (ADHD)

The patient with attention deficit hyperactivity disorder has difficulty focusing his attention, engaging in quiet passive activities, or both. Some patients have an attention deficit without hyperactivity; they're less likely to be diagnosed and receive treatment. Although attention deficit hyperactivity disorder is present at birth, diagnosis before age 4 or 5 is difficult unless the child exhibits severe symptoms. Some patients, however, aren't diagnosed until they reach adulthood. Attention deficit hyperactivity disorder is thought to be a physiologic brain disorder with a familial tendency. Some studies indicate that it may result from altered neurotransmitter levels in the brain. Scientists are not sure what causes ADHD, although many studies suggest that genes play a large role. Like many other illnesses, ADHD probably results from a combination of factors. In addition to genetics, researchers are looking at possible environmental factors, and are studying how brain injuries, nutrition, and the social environment might contribute to ADHD

Predisposing Factors for Attention Deficit Hyperactivity Disorder (ADHD)

Physiological

• Genetics. A number of studies have indicated that hereditary factors may be implicated in the predisposition to ADHD. Siblings of hyperactive children are more likely than normal children to have the disorder.
• Biochemical. Abnormal levels of the neurotransmitters dopamine, norepinephrine, and possibly serotonin have been suggested as a causative factor.
• Prenatal, Perinatal, and Postnatal Factors. Maternal smoking during pregnancy has been linked to ADHD . Premature birth, fetal distress, precipitated or prolonged labor, and perinatal asphyxia have also been implicated. Postnatal factors include cerebral palsy, epilepsy, and other central nervous system abnormalities resulting from trauma, infections, or other neurological disorders.

Psychosocial

• Environmental Influences Disorganized or chaotic environments or a disruption in family equilibrium may predispose some individuals to ADHD. A high degree of psychosocial stress, maternal mental disorder, paternal criminality, low socioeconomic status, and foster care have been implicated.