The existence of ADHD as a clinically impairing condition is irrefutable. Though the etiology of the condition and precise symptom profile remain debatable concepts, presenting symptoms and impairing consequences are easily observed and measured. In light of current theories portraying ADHD as a condition of impaired development, it should not be a great philosophical nor academic leap to accept the condition as presenting throughout the life span. Yet scientific method requires more than just hypotheses and theory before belief can confidently be described as fact. Though thousands of peer reviewed studies dealing with ADHD in childhood have been published, the literature still contains fewer than 100 peer reviewed articles dealing with adult ADHD. The numbers of studies have been increasing significantly year-by-year, including the ongoing reported results from a number of longitudinal studies following children with ADHD into their adult years. Yet, as with any emerging condition, each published study holds the promise of new data, insight and perhaps a new path to follow in regards to ADHD in the adult years. Time will determine which paths bear fruit and which may result in dead ends.
It is an unfortunate phenomena that for the time being the field of adult ADHD is driven as much if not more by lay publications and experts whose "facts" are primarily based upon their clinical experiences. Clinical practice for many professionals working with adults with ADHD is guided more by these phenomena and less by available scientific literature. In clinical practice and even research the misunderstanding of the developmental nature of the diagnosis, particularly the fact that a set of childhood derived symptoms are currently applied to adults causes misunderstanding and misinformation. For example, some researchers have suggested, based upon research review, that as adults grow older fewer meet the childhood criteria for ADHD and therefore most recover. Yet, when normative data is collected across age and gender in adulthood, it is clear that ADHD symptoms persist and cause impairment for a significant group of adults throughout their adult years. These adults with ADHD also display greater self-reported psychological problems, more driving problems and more frequent changes in employment. They often have a history of inconsistent educational experience and multiple marriages. I am not suggesting that it would be impossible for someone with ADHD to obtain a graduate degree or develop a stable marriage, just that those with ADHD are less likely to do so than individuals in the general population.
In the last fifteen years the biopsychosocial nature of this condition across the life span has become increasingly apparent. Adults with ADHD demonstrate longer delay when their attention is misdirected. They have difficulty switching tasks. On neuropsychological testing they often have trouble with sustained effort, planning, organization, visual tracking and auditory attention. Some researchers have suggested that these weaknesses reflect problems with executive control or frontal lobe skills. Interestingly, most of these skills are not strongly related to intelligence.
Though some authors have suggested that ADHD may reflect an adapted pattern of skills developed based upon an evolutionary model, the emerging research literature is sobering. Not a single childhood nor adult study exists to suggest those with ADHD hold any type of advantage over individuals without this condition. Further, the increased recognition that ADHD reflects not so much a problem sitting still or paying attention but rather a problem of self-regulation or self-control provides a workable hypothesis to explain the myriad of problems currently identified for adults with histories of ADHD. This plausible explanation for ADHD explains that rather than representing an adapted or evolved set of valuable qualities, individuals with ADHD suffer from weaknesses in the development of efficient self-regulatory and executive functions. Qualities of ADHD appear to place individuals at the lower tail of an adaptive bell curve for these skills. This should not pathologize or those with ADHD but help readers understand and empathize with their plight.
It has been estimated from available literature that approximately one third of adults with ADHD progress satisfactorily into their adult years. Another one third continue to experience some problems while the final one third continues to experience and often develops significant problems. By combining a number of well conducted outcome studies it is reasonable to conclude that 10% to 20% of adults with histories of ADHD experience few problems. Sixty percent continue to demonstrate symptoms of ADHD and experience social, academic and emotional problems to at least a mild to moderate degree. Finally, 10% to 30% develop anti-social problems in addition to their continued difficulty with ADHD and other comorbid problems such as depression and anxiety. Many of these negative outcomes are linked to the continuity, severity and persistence of ADHD symptoms. There is also very limited data to suggest that females at outcome when controlling for initial presentation are at reduced risk for some problems in comparison to males. Their rates of comorbid depression and anxiety are likely equal, if not higher, however. A number of ongoing studies are demonstrating that adults with ADHD report very similar symptoms as described in children with ADHD. The impact of these symptoms upon their lives, however, is clearly different. Further, at least to a mild degree, most adults in the general population will report experiencing some symptoms related to inattention and impulse control.
Ultimately the life course for any human being is impacted by varied and multiple factors. An increasing body of literature operating from a developmental pathways model, however, has demonstrated that a number of childhood variables can be used to predict in a general way risk of adult problems as well as identifying insulating or protective factors that reduce risk and increase the chances of a satisfactory transition into adult life. As a field, researchers dealing with childhood disruptive disorders, including ADHD are slowly beginning to examine these protective factors. For the time being there is limited data available specific to the population of individuals with ADHD in this regard. It is quite likely, however, that those factors that insulate and protect children from other psychiatric conditions, including disruptive disorders likely affect those with ADHD. Thus, living in an intact household above the poverty level with parents free of psychiatric problems, consistent in their parenting style, emotionally and physically available to their children, appear to be among the most powerful variables predicting good outcome. Specifically in regards to ADHD the development of aggressive behavior, depression or substance abuse may increase risk of adverse adult outcome. Additional negative outcome variables, include parental psychopathology, learning disability and lower intellect.
The good news is that there is an emerging trend to suggest that the combination of medication, cognitive therapy and life coaching appears to significantly benefit adults with ADHD. I am optimistic that as research and clinical attention turns to the adult ADHD population, our ability to define and prescribe both psychological and pharmacological interventions for this population will result in treatment success consistent with that reported during the childhood years.
In the winter of 2001, Dr. Goldstein and Dr. Phyllis Ann Teete’s edited work, Clinical Interventions for Adult ADHD (Academic Press) will be published. Drs. Keith Conners, Russell Barkley, Michael Gordon, Tim Wilens, Robert Brooks, Art Robin, Tom Phelan and Kathleen Nadeau are among twenty contributors to this volume.
