Attention deficit hyperactivity disorder (ADHD)

Individuals with ADHD have many symptoms, including extreme inattentiveness and/or impulsiveness and hyperactivity. Many people with ADHD continue to have symptoms throughout life. The symptoms of ADHD fall into the following two broad categories.

Inattention: Symptoms of inattention include failure to pay close attention to details, trouble keeping focused during play or tasks, appearing not to listen when spoken to, failure to follow instructions or finish tasks, avoiding tasks that require a high amount of mental effort and organization such as school projects, frequently losing items required to facilitate tasks or activities such as school supplies, excessive distractibility, forgetfulness, procrastination, inability to begin an activity, difficulties with household activities (cleaning, paying bills, etc.), difficulty falling asleep, frequent emotional outbursts, easily frustrated, and easily distracted.

Hyperactivity-impulsive behavior: Hyperactive-impulsive symptoms include fidgeting with hands or feet or squirming in seat, leaving seat often even when inappropriate, running or climbing at inappropriate times, difficulty in quiet play, frequently feeling restless, excessive speech, answering a question before the speaker has finished, failure to wait one's turn, interrupting the activities of others at inappropriate times, and impulsive spending leading to financial difficulties.

A positive diagnosis is usually only made if the person has experienced six of the above signs and symptoms for at least three months. Symptoms must appear consistently in varied environments (not only at home or school) and interfere with general functioning.

Children who grow up with ADHD often continue to have signs and symptoms as they grow into adulthood. Adults living with ADHD may experience challenges in the areas of self-control, self-motivation, and decision making as well as depression, anxiety and substance abuse. Adults may have more signs and symptoms of inattention and less of hyperactivity-impulsive behavior than children.

Diagnosis of ADHD is mainly based on observed symptoms and behavior.

Clinical testing: The American Academy of Pediatrics Clinical Practice Guideline for children with ADHD states that a diagnosis should be based upon the following three criteria:

1. The use of explicit criteria for the diagnosis using the DSM-IV-TR (Diagnostic Criteria of Mental Disorders: the clinical reference for psychiatric illnesses). The Conners' Rating Scale is commonly used.

2. The importance of obtaining information about the child's symptoms in more than one setting. This is completed by obtaining a personal medical and family history from parents, teachers, and the patient.

3. The search for coexisting conditions that may make the diagnosis more difficult or complicate treatment planning. This is done with psychological and intelligence testing.

Analytical testing: Some clinicians use brain scan technology to determine if there is a problem with brain function or blood flow. These tests include MRI (Magnetic Resonance Imaging), PET (Positron Emission Tomography), and SPECT (Single Photon Emission Computed Tomography). Scientists have concluded, however, that there is not enough evidence to use these methods to determine if an individual has ADHD.

Computerized tests: These generally determine the attention span of the individual. However, due to a high rate of false negatives, this testing modality is not commonly used to determine if an individual has ADHD.

Individuals with ADHD struggle to function normally in daily life. Children often struggle in the classroom, which can lead to academic failure and ridicule from other children and adults.

Children with ADHD are much more likely to experience minor trauma, such as fractures and cuts, than are other children. Adults and teenagers are also more likely to become involved in car accidents and have other injuries. Individuals with ADHD may also be more likely to have trouble with following the law and commit crimes.

As many as one in three children with ADHD also have other psychological or developmental conditions.

Oppositional defiant disorder (ODD): Generally defined as a pattern of negative, defiant and hostile behavior toward authority figures, ODD tends to occur more frequently in children who are impulsive and hyperactive and is especially common in boys.

Conduct disorder: A more serious condition than ODD, conduct disorder is marked by distinctly antisocial behavior such as stealing, fighting, destroying property, harming people and animals, and committing crimes. Children with conduct disorder need immediate help.

Depression: Depression may occur in both children and adults with ADHD. It's more likely to appear when there is a family history of depression.

Anxiety disorders: Anxiety disorders tend to occur fairly often in children with ADHD and may cause overwhelming worry and nervousness as well as physical signs and symptoms, such as a rapid heartbeat, sweating and dizziness. Although anxiety disorders can cause severe symptoms, most people can be helped with therapy or medication. Once anxiety is under control, children are better able to deal with the problems arising from ADHD.

Learning disabilities: Children with both ADHD and learning disabilities are the children most in need of special education services.

Tourette's syndrome: Many children with ADHD are at increased risk of Tourette's syndrome, a neurological disorder characterized by compulsive muscular or vocal tics.

Alcohol and drug abuse: Individuals with ADHD may be more likely to develop addiction problems with alcohol or drugs, due to factors including altered brain function and the continued use of stimulants.

The exact cause of ADHD remains unknown. Most of the causes have been reported to be dysfunction in the brain and nervous system.

Altered brain function: Dopamine is a brain neurochemical necessary for proper function. Research has found that individuals with ADHD may have a deficiency of dopamine. Also, individuals with ADHD may have decreased blood flow to the brain.

Thyroid disorders: Thyroid abnormalities have been associated with ADHD and other childhood psychiatric disorders.

Head injuries: Head trauma in childhood may cause neurological problems leading to the development of ADHD.

Drug induced: Hyperactivity may be caused by high or repeated doses of caffeine or stimulants.

Heredity: ADHD tends to run in families. About one in four children with ADHD have at least one relative with the disorder, and when one identical twin has ADHD, the other twin almost always has it as well.

Diet: Recent studies have found that children with ADHD may have vitamin and mineral deficiencies. Decreases in zinc, essential fatty acids, iron, B-vitamins, and glyconutrients have been reported in children with ADHD. Protein deficiencies may also contribute to the development of ADHD.

Food and additive allergies: Food allergies (including wheat, soy, corn, dairy, shellfish, nuts from trees such as walnuts, and peanuts) and food additives (such as dyes and preservatives) have been reported to aggravate the symptoms of ADHD.

Heavy metal toxicity and other environmental toxins: Environmental toxins (chemicals) and heavy metal (including lead, mercury, and cadmium) exposure during pregnancy or in childhood may contribute to the development of ADHD. Smoking during pregnancy has been reported to increase the chances of developing ADHD.

Violence, abuse and other emotional traumas: While no conclusive evidence has been offered that parenting methods can cause ADHD in otherwise normal children, some clinicians believe this is the case.