Symptoms of Adult ADHD

What are the Symptoms of Adult ADHD?

ADHD (attention-deficit/hyperactivity disorder) is a neurobiological condition, consisting of symptoms of inattention and/or hyperactivity that are significant enough to interfere with a person’s functioning.

ADHD develops in childhood but can continue into adulthood. Adult ADHD is simply someone over the age of 18 with ADHD who continues to have symptoms of the disorder. It is not listed as a separate disorder for children vs. adults.

In order to meet criteria for a diagnosis of ADHD you must have a collection of symptoms. The symptoms fall into two categories: hyperactive/impulsive and inattentive.

Symptoms of hyperactivity include:

  • fidgeting
  • restlessness
  • difficulty sitting or engaging in leisure activities quietly
  • talking excessively
  • constantly being in motion as if driven by a motor.

Symptoms of impulsivity include

  • impatience
  • difficulty waiting in line
  • butting into conversations or activities in an intrusive way

The second category is inattentiveness and includes symptoms such as:

  • failure to pay attention to details
  • making frequent careless mistakes
  • difficulty sustaining attention
  • appearing not to pay attention when spoken to
  • difficulty following through on tasks
  • avoiding tasks that require sustained mental effort
  • frequently loses things
  • being easily distractible
  • forgetfulness.

An individual can be classified as predominately inattentive type, predominately hyperactive-impulsive type, or as combined type if they meet criteria for both subtypes.

While many people may struggle with some of these symptoms, it is the frequency, duration, and intensity of the symptoms that that make this a diagnosis. For the diagnoses to be made, the symptoms must have been present by the age of 7, symptoms must be present for more than 6 months, there must be impairment in at least 2 settings (e.g., work or school and at home), and it must cause significant impairment.

You can find the full DSM-IV criteria at

Who gets ADHD?

ADHD is a highly heritable condition (heritability index = .77 in twin studies) that affects 4.4% of the adult population. It occurs more frequently in men than women, ranging from 2:1 to 9:1 depending on the subtype. The gender ratio is less pronounced in the inattentive subtype than the other subtypes. It is estimated 3%-7% of school age children meet criteria for ADHD (DSM-IV-TR, 1994, Kessler et al, 2006).

The conventional wisdom in the medical community used to be that children with ADHD “grew out of” the disorder. However, more recent research indicates about half of children with ADHD continue to have significant symptoms as adults. Unfortunately, of the 4.4% of adults in the US that meet criteria for ADHD, fewer than 11% received treatment for it in the year prior to the study (Kessler, 2006).

Some well known people with ADHD include

  • Kinko’s founder Paul Orfalea
  • Justin Timberlake
  • JetBlue CEO David Neeleman
  • Ansel Adams
  • Dennis Rodman
  • Mariette Hartley
  • Howie Mandel
  • Sir Anthony Hopkins

(Connaughton, D., 2002, Ek, U., et al, 2007 as well as other online sources)

How does ADHD affect adults?

As mentioned earlier, the criteria are the same for adults and children, though impulsive/hyperactive symptoms are less common in adults. Many adults with ADHD are extremely resourceful and have found ways to compensate for the diagnosis, such as hiring people to handle organizing their affairs or developing their own organizational strategies to compensate. However, many times they perform below their level of ability as a result of the symptoms. It can affect many areas of their life outside of work as well.

ADHD frequently co-occurs with many other emotional and learning disorders. It is estimated that 50-75% of adults with ADHD suffer from another mental health disorder. 38.3% of adults with ADHD also have mood disorder, 47.1% have an anxiety disorder, and 15.2% have a substance use disorder.