ADDults: ADHD in Adulthood

by Leslie E. Packer, PhD
This article last updated July 2010


In one of the seminal overviews of ADHD in adults, Wender, Wolf, and Wasserstein (2001) noted that of the 3 to 10% of children diagnosed with ADHD, one- to two-thirds (somewhere between 1 and 6% of the general population) would continue to have symptoms of ADHD in adulthood. Subsequent data indicate that the prevalence of ADHD in adults is somewhere between 3.4% and 4.4% of the population. If the CDC’s estimated prevalance of 5% for childhood ADHD is correct, that would suggest that a significant percentage of cases of ADHD either persist into adulthood and/or there are cases of ADHD that emerge after age 7.

Because diagnostic criteria for ADHD were developed for children, one of the first issues was what diagnostic criteria to use for adults. McGough and Barkley (2004) discussed the issues in diagnosis. Subsequently, Faraone, Faraone, Biederman, et al. (2006) found that adults who met the diagnostic criteria for ADHD except for “onset before age 7” criteria were comparable to those adults with ADHD who had met the criteria before age 7, suggesting that the age 7 criterion may be too low. Adults who had some symptoms of ADHD but never met full criteria (apart from the age criterion) have a different pattern than those who met all criterion other than age.

The DSM-5 task force is considering changes to the diagnostic criteria for ADHD that would affect adults. They note that the DSM-IV criteria were criticized by professionals as:

Certain manifestations of adult ADHD are not well represented in the criteria, including the decline in the number of criteria with age without a reduction in impairment.

Age of onset was set arbitrarily and there are many reports of cases with an onset after age 7.

A variety of options are under consideration. These are outlined here (pdf).

If adults with ADHD have the same pattern of deficits as children and teens with ADHD, do they also have the same pattern of comorbid disorders? Some research suggests yes, but additional problems tend to emerge during the teen years or in adulthood that make the treatment and management of adult ADHD more challenging.

In 2005, McGough, Smalley, et al. studied 435 parents of children with ADHD. Some parents had been diagnosed with ADHD at some point in their lives, some had persisting ADHD, and some had no ADHD. Parents with ADHD reported more lifetime history of mental problems; 87% had at least one and 56% had at least two other psychiatric disorders, in contrast to 64% and 27% of parents who had never had ADHD. Those with ADHD reported more disruptive behavior, oppositional defiant disorder and conduct disorder, more substance use, and more mood and anxiety disorders than the no-ADHD parents. The substance use disorder was not directly attributed to ADHD and could be accounted for by male gender, a history of disruptive behavior disorders, and lower socioeconomic status. Their findings were consistent with studies of teens with persisting ADHD, but do not address reportedly higher rates of personality disorders in adults with ADHD. Research by Barkley and Murphy (2007), however, found that although adults with ADHD had higher rates of personality disorders than non-ADHD adults, the rates were no higher than for adults with other disorders.

A study by Kessler, Adler and their colleagues (2006) provides additional data on the prevalence and comorbidity issues. Figure 1, below, shows the rates of different types of disorders in adults with ADHD:

As can be seen, almost half of adults with ADHD had one or more anxiety disorders. As in other studies, many adults had more than one type of comorbid disorder.. In the data above, “impulse control disorder” refers to Intermittent Explosive Disorder.

Although these data in Fig. 1 give some sense of what percent of ADHD adults have particular types of problems, the figure does not provide any comparison to adults with ADHD. Those comparisons are provided in Figures 2 and 3 for anxiety disorders and mood disorders, respectively.

The Kessler study found high rates of functional impairment for adults with ADHD. Significantly, most cases of ADHD were untreated, although many adults had received treatment for the comorbid disorders, a finding also reported by Fayyad et al. (2007) (pdf). Whether treatment for ADHD would have or could change the outcomes is unknown at this point.


Almost any ADDult or their spouse may lament all the time spent looking for lost keys, the number of times the ADDult has “forgotten” to do something, or starts a project but never finishes it, etc. These types of problems are often indicative of neuropsychological dysfunctions in working memory or executive functions, as discussed in the section on executive functions. An ADDult who has executive dysfunctions (EDF) is not being “lazy” or “irresponsible.” That individual has a neurologically based deficit and needs to learn strategies to work around the deficits, and/or may need treatment or coaching to help them learn effective strategies. Treating ADHD alone is generally not sufficient, and as Biederman, Petty and their colleagues found (2006) found, EDF contributes significantly to worse outcomes over and above the impact of ADHD.