It has been estimated that 3 percent to 5 percent of school-aged children suffer from attention-deficit hyperactivity disorder, or ADHD, according to the Partners Resource Network 4. ADHD is a neurobehavioral disorder and not all people with ADHD share the same symptoms. ADHD has three distinct subtypes: predominantly inattentive, predominantly hyperactive-impulsive and a combination of the two. The predominantly inattentive type of ADHD is often referred to as ADD. As a mental disorder, ADHD is diagnosed by the guidelines presented in the Diagnostic and Statistical Manual of Mental Disorders, or DSM-IV.

Causes of ADHD

It is not clear what causes ADHD, although the disorder appears to run in families, according to the American Academy of Pediatrics 2. Smoking and drinking during pregnancy have also been linked to the risk of a child being diagnosed with ADHD later on, reports Certain environmental toxic substances, such as lead, have also been linked to ADHD.

Inattentive ADHD Diagnosis

To be diagnosed with predominantly inattentive ADHD a person must exhibit six out of nine specific behaviors, according to the DSM-IV. These symptoms must have lasted a minimum of six months. At least some of the symptoms must have been present before the person turned 7 and they must have manifested in at least two settings such as home and school. There must be clear evidence that a person’s symptoms are significantly affecting his performance at work, school, or social settings.

ADD Symptoms at School and Work

A person with ADD does not typically do well at school or work. His work is often messy and full of careless mistakes. Timing is difficult for an ADD patient. He constantly underestimates how long it takes for him to finish a task. Frequently, work has been left until the last minute to finish and then put together in a rush. Many jobs never get finished and the person with ADD constantly starts a new task before finishing the old ones. Because of this, an adult with ADD may lose his job and child with ADD may be punished for leaving his homework at home.

ADD Symptoms in Social Settings

ADD patients do not usually have many friends. This might be because they appear inattentive and fail to listen to other people. When having a conversation, a person with ADD shifts from one topic to another and frequently forgets when and where she was supposed to meet someone. A child with ADD may not want to follow the rules of a game and may fail to wait for her turn in games or conversation. As a result, both the child herself and her classmates may report that she is not well liked.

ADD also affects the way a person thinks and remembers. As time passes, an ADD patient may learn to avoid tasks that require sustained mental effort and tell himself that he is not that smart. He may set the bar low and lose interest in many activities. Not surprisingly, it has been reported that the risk for depression is three times higher in ADHD children than in healthy children, says Dr. David Rabiner, an associate research professor at Duke University, in 1. A person with ADD may forget where he put his briefcase, when his daughter’s birthday is and where he parked his car. He is easily distracted by things that a healthy person would not even notice. The sound of a car driving by might make a child with ADD forget what he was doing.