Attention-Deficit/Hyperactivity Disorder (ADHD)
Attention-Deficit/Hyperactivity Disorder (ADHD) is the most common behavior disorder diagnosed in children and teens. ADHD refers to a group of symptoms that begin in early childhood and can continue into adulthood, causing difficulties at home, at school, at work, and within the community if not recognized and treated.

Difference between ADHD and ADD?
ADHD (Attention-Deficit/Hyperactivity Disorder) is the term used in the current Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition (DSM-IV-TR) diagnostic criteria. ADD (Attention Deficit Disorder) with or without hyperactivity is the older term from the DSM-III-R.

Three Subtypes / Types of Attention-Deficit/Hyperactivity Disorder

Adult ADHD
Attention-deficit/hyperactivity disorder (ADHD) in an adult often goes unnoticed because the person may maintain relationships, stay organized, and hold a steady job. It is not unusual for a parent to discover he or she has ADHD when his or her child is diagnosed with the disorder. The key to the diagnosis of ADHD for an adult is the presence of symptoms before he or she was 7 years of age. 

Hyperactivity in adults is often seen as:

 Inattention in adults is often seen as: