You may have heard the terms ADD and ADHD used interchangeably. Attention-deficit disorder (ADD) and attention-deficit/hyperactivity disorder (ADHD) are indeed names for the same condition, it's just that ADHD has had several name changes in the last three decades.
Attention-deficit/hyperactivity disorder (ADD/ADHD) is classified as a neurodevelopmental disorder; it is neurologically-based and appears early in childhood, typically before a child begins school, and impairs development of personal, social, academic, and/or occupational functioning. It often involves dysfunction in attention, memory, perception, language, problem-solving, or social interaction. Onset is frequently by age 4 and invariably before age 12, and the typical age of initial diagnosis is between 8 and 10 years of age. Signs may include clumsiness, minor signs of non-specific cerebral impairment, and perceptual-motor dysfunctions (related to sensory processing).
According to the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5), there are 3 types of ADD/ADHD: Predominantly inattentive, Predominantly hyperactive/impulsive, and Combined. ADD/ADHD is about twice as common in boys, but the ratios vary by type. Behavioral history may reveal low frustration tolerance, opposition, aggressiveness, poor social skills and peer relationships, sleep disturbances, anxiety, depression, and mood swings, among other concerns.
Core symptoms are inattention (making careless mistakes, not listening when spoken to directly, failing to finish tasks, or being easily distracted), impulsivity and hyperactivity (frequent fidgeting, squirming, being constantly in motion, difficulty playing quietly, or excessive talking). Symptoms must be present for more than 6 months, are more pronounced than expected for the child’s developmental level, occur in at least 2 settings, such as home and school, are present before age 12, and interfere with normal day to day functioning at home/school. Diagnosis is based on clinical criteria using medical, developmental, educational, and psychologic evaluations.