Attention-deficit/hyperactivity disorder (ADHD) may be the most common chronic, undiagnosed psychiatric disorder in adults. ADHD is characterized by restlessness, overactivity, disorganization, impulsivity, and inattention; and as further characterized in the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, Text Revision (DSM-IV-TR). For most cases, an adult ADHD diagnosis is preceded by symptoms in childhood, which is a time when the disorder is rarely inquired about and usually overlooked.

ADHD has been recognized in children for several decades, and the importance of detection and treatment is well established. Whereas it was initially believed that children outgrew the disease, researchers now know that approximately two thirds of children affected with ADHD symptoms carry the condition into adolescence and then into adulthood. Consequently, >4% of adults in the United States have ADHD. Nevertheless, the disorder is unrecognized and untreated in the vast majority of these people.

How common is attention-deficit/hyperactivity disorder (ADHD), and does the prevalence change from adolescence to adulthood?

A number of studies have reviewed the persistence of attention-deficit/hyperactivity disorder (ADHD) from childhood into adolescence and adulthood as well as how the disorder changes over the lifespan of the illness. Recently, a metaanalysis found that the worldwide prevalence of childhood ADHD is ∼8%, and approximately two thirds of children with ADHD continue to have the disorder as adults. The National Comorbidity Survey is possibly the most comprehensive, up-to-date study examining the prevalence of community-based prevalence of adult ADHD; 4.4% of patients in that study were found to have ADHD. The prevalence of ADHD among adolescent patients seems to lie somewhere between the prevalence rates for children and adults.

Although the symptoms of attention-deficit/hyperactivity disorder (ADHD) can be found in many “normal” people, these symptoms are present to a greater extent in those affected by the disorder. In these patients, ADHD symptoms cause substantial functional impairment. Therefore, the goal of treatment is not simply to reduce core symptoms, but also to decrease the level of impairment caused by these symptoms.

Common impairments in adolescents and adults include academic and occupational problems that are particularly evident in the context of tasks requiring a high degree of organization or attentional function. These impairments result in problems related to task completion, prioritizing work and other obligations, and time management, etc. These symptoms often impact successful completion of tasks in school or at work, and can also result in a variety of problems in initiating and managing relationships (Slide 1).

Mood and anxiety disorders often co-occur with ADHD in adults. The accumulation of experiences related to impaired academic and/or occupational performance, and or persistent relationship problems, due to the symptoms of ADHD, can lead to either depressed mood or anxiety related to performance and/or social situations. Therefore, in treating adults with ADHD, reduction of those co-occurring symptom presentations is also an important goal.

What exactly is known today about the impact of the adult form of attention-deficit/hyperactivity disorder (ADHD) in society?:

In a recent study to examine the societal impact of attention-deficit/hyperactivity disorder (ADHD), 500 patients diagnosed with ADHD and 501 participants with no substantial signs or symptoms of ADHD were studied. Subjects were asked several questions about their quality of life, employment, job satisfaction, and other aspects of their well-being and functionality. Income, which is an important marker for the degree of productivity for an individual in society, was also assessed. ADHD can profoundly affect the performance of individuals in the workplace (Slide 1), and this study found that having ADHD reduced an individual's income by an average of ∼$10,000 per year. If that loss of income is extrapolated to all adults in the United States who have ADHD, it suggests that the economy is losing around $70 billion a year to $115 billion a year in productivity, as measured by loss of income. The range was broad because different models with varying assumptions were applied to project income loss over time. Nevertheless, based on these numbers, it is reasonable to estimate that the population is losing ∼$100 billion annually in productivity due to ADHD.

Income loss was found at all levels of education, but it was greatest among patients who had advanced degrees of education; so it seems that the disease may have a more pronounced impact on income among those in the higher income brackets.