Attention deficit hyperactivity disorder (ADHD) is a common neurodevelopmental disorder most frequently diagnosed in children.

According to the Centers for Disease Control and Prevention (CDC), ADHD is most often identified in the elementary school years. However, adults can demonstrate symptoms and be diagnosed as well.

Boys are more than twice as likely to be diagnosed with ADHD than girls, but females are not necessarily less susceptible. Females with ADHD are likely underdiagnosed for a variety of reasons, including some differences in symptoms and an unequal focus on males in research.

ADHD was originally called hyperkinetic reaction of childhood. It wasn’t until the 1960s that the American Psychiatric Association (APA) formally recognized it as a mental disorder, and in the 1980s, the diagnosis became known as “attention deficit disorder with or without hyperactivity.”

Read more for a timeline of ADHD.

ADHD was first mentioned in 1902. British pediatrician Sir George Frederic Still described “an abnormal defect of moral control in children.” He found that some affected children could not control their behavior the way a typical child would, but they were still intelligent.

The Food and Drug Administration (FDA) approved Benzedrine as a medication in 1936. Dr. Charles Bradley stumbled across some unexpected side effects of this medication the next year. Young patients’ behavior and performance in school improved when he gave it to them.

However, Bradley’s contemporaries largely ignored his findings. Many years later, doctors and researchers began to recognize the benefit of what Bradley had discovered.

The APA issued the first “Diagnostic and Statistical Manual of Mental Disorders (DSM)” in 1952. This manual listed all of the recognized mental disorders. It also included known causes, risk factors, and treatments for each condition. Doctors still use an updated version today.

The APA did not recognize ADHD in the first edition. A second DSM was published in 1968. This edition included hyperkinetic reaction of childhood for the first time.

The FDA approved the psychostimulant methylphenidate (Ritalin) in 1955. It became more popular as an ADHD treatment as the disorder became better understood and diagnoses increased. The medication is still used to treat ADHD today.

The APA released a third edition of the DSM (DSM-III) in 1980. They changed the name of the disorder from hyperkinetic reaction of childhood to attention deficit disorder (ADD). Scientists believed hyperactivity was not a common symptom of the disorder.

This listing created two subtypes of ADD: ADD with hyperactivity, and ADD without hyperactivity.

The APA released a revised version of the DSM-III in 1987. They removed the hyperactivity distinction and changed the name to attention deficit hyperactivity disorder (ADHD).

The APA included the three symptoms of inattentiveness, impulsivity, and hyperactivity into a single list of symptoms and did not identify subtypes of the disorder.

The APA released the fourth edition of the DSMin 2000. The fourth edition established the three subtypes of ADHD used by healthcare professionals today:

ADHD cases began to climb significantly in the 1990s. There may be a few potential factors behind the rise in diagnoses:

  • Doctors were able to diagnose ADHD more efficiently.
  • More parents were aware of ADHD and were reporting their children’s symptoms.
  • More children were actually developing ADHD.

More and more medications to treat the disorder became available as the number of ADHD cases rose. The medications also became more effective at treating ADHD. Many have long-acting benefits for people who need relief from symptoms for longer periods.

Scientists are trying to identify the causes of ADHD as well as possible treatments. A 2020 review of studies points to a very strong genetic link. Children who have biological parents or siblings with the disorder are more likely to have it.

It’s not currently clear what role environmental factors play in determining who develops ADHD. Researchers are dedicated to finding the underlying cause of the disorder. They’re aiming to make treatments more effective and to help find cures.