Attention deficit hyperactivity disorder (ADHD) is diagnosed in three to five percent of school-aged children, according to the National Institutes of Health (NIH). The disorder is characterized by symptoms of inattention, impulsiveness and hyperactivity, which affect the child's behavior and performance in school. However, a patient with ADHD may have varying symptoms, depending on the subtype he is diagnosed with. The National Institute of Mental Health (NIMH) states that there are three ADHD subtypes: predominantly hyperactive-impulsive, predominantly inattentive and combined hyperactive-impulsive and inattentive.
Predominantly Hyperactive-Impulsive ADHD
The predominantly hyperactive-impulsive subtype of ADHD shows mainly hyperactive and impulsive symptoms. Examples of symptoms are the patient fidgeting with either her hands or feet and interrupting others. The patient may also have problems waiting her turn. Talking excessively and blurting out answers are also symptoms. The patient may leave her seat at inappropriate times, such as during class, and may also run around or climb on things when she should be still. She may also have trouble playing quietly and always seem to be on the go. The patient must have six or more symptoms of hyperactivity for a diagnosis. With this subtype, inattention may also be present, but the patient will have less than six symptoms of inattention for a diagnosis.
Predominantly Inattentive ADHD
A patient with the predominantly inattentive ADHD subtype has six or more inattention symptoms. Symptoms include making careless mistakes. The patient is also easily distracted and has problems sustaining attention. He may also have difficulty with organization, resulting in forgetfulness and losing items, like toys and homework. Following directions and completing tasks are also problems. As a result of the attention problems, the patient may avoid tasks that need sustained mental effort, such as schoolwork. The patient can also have hyperactive and impulsive symptoms, though less than six must be present to qualify for this subtype. The NIMH notes that a child with predominantly inattentive ADHD is less likely to act out, and parents and teachers may not notice at first that he has the disorder.
Combined Hyperactive-Impulsive and Inattentive ADHD
To be diagnosed with the combined hyperactive-impulsive and inattentive subtype of ADHD, the patient must have six or more symptoms of inattention and six or more symptoms of hyperactivity and impulsiveness. The NIMH states that most children have this type of ADHD. The Mayo Clinic adds that the symptoms must appear before age seven and last for at least six months for the child to be diagnosed with any subtype of ADHD.
