Skip to main page content
Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
Review
, 10, 99

A Systematic Review and Analysis of Long-Term Outcomes in Attention Deficit Hyperactivity Disorder: Effects of Treatment and Non-Treatment

Affiliations
Review

A Systematic Review and Analysis of Long-Term Outcomes in Attention Deficit Hyperactivity Disorder: Effects of Treatment and Non-Treatment

Monica Shaw et al. BMC Med.

Abstract

Background: In childhood, attention deficit/hyperactivity disorder (ADHD) is characterized by age-inappropriate levels of inattentiveness/disorganization, hyperactivity/impulsiveness, or a combination thereof. Although the criteria for ADHD are well defined, the long-term consequences in adults and children need to be more comprehensively understood and quantified. We conducted a systematic review evaluating the long-term outcomes (defined as 2 years or more) of ADHD with the goal of identifying long-term outcomes and the impact that any treatment (pharmacological, non-pharmacological, or multimodal) has on ADHD long-term outcomes.

Methods: Studies were identified using predefined search criteria and 12 databases. Studies included were peer-reviewed, primary studies of ADHD long-term outcomes published between January 1980 to December 2010. Inclusion was agreed on by two independent researchers on review of abstracts or full text. Published statistical comparison of outcome results were summarized as poorer than, similar to, or improved versus comparators, and quantified as percentage comparisons of these categories.

Results: Outcomes from 351 studies were grouped into 9 major categories: academic, antisocial behavior, driving, non-medicinal drug use/addictive behavior, obesity, occupation, services use, self-esteem, and social function outcomes. The following broad trends emerged: (1) without treatment, people with ADHD had poorer long-term outcomes in all categories compared with people without ADHD, and (2) treatment for ADHD improved long-term outcomes compared with untreated ADHD, although not usually to normal levels. Only English-language papers were searched and databases may have omitted relevant studies.

Conclusions: This systematic review provides a synthesis of studies of ADHD long-term outcomes. Current treatments may reduce the negative impact that untreated ADHD has on life functioning, but does not usually 'normalize' the recipients.

Figures

Figure 1
Figure 1
Number of outcome results by group. The pie chart shows the number of outcome results by outcome group. Note that the number of outcomes exceeds the number of studies included, because some studies examined more than one outcome. The greatest number of outcomes was measured for drug use/addictive behavior, followed by academic, antisocial behavior, social function, occupation, self-esteem, driving, services use, and obesity outcomes.
Figure 2
Figure 2
Total number of studies of long-term outcomes of attention deficit hyperactivity disorder (ADHD) published by year.
Figure 3
Figure 3
Outcome groups by ages. (A) This graph shows the mid-range/mean ages of the participants measured in studies of specific outcomes. The light blue portion of the bars represent children 6 to 12 years old, the dark blue bars represent adolescents (13 to 17 years) and the violet bars represent adults (18 to 84 years). The greatest proportion of outcomes examined in children can be seen on the bottom (services use), whereas a greater proportion of outcomes examined in adults can be seen on the top (occupation). (B) This graph shows the proportion of outcomes reported within each age category. Each colored section corresponds to the outcomes reported for each outcome group as a proportion of the total number of outcomes reported for that age category.
Figure 4
Figure 4
Untreated participants with attention deficit hyperactivity disorder (ADHD) compared with non-ADHD controls. The percentage of the total number of outcomes is provided for each bar. The total number of studies represented in each bar is shown in parentheses. The green bar shows the percentage of outcome results reported as similar (26% of outcomes; 89 studies) in untreated participants with ADHD compared with non-ADHD participants. The blue bar shows the percentage of outcome results reported as poorer (74% of outcomes; 244 studies) in untreated participants with ADHD compared with non-ADHD participants. The sum of the numbers of studies shown under each bar does not equal the total number of studies represented in this figure; several studies reported some outcomes that were similar to control and some outcomes that were poorer than controls. Therefore these studies are represented in both types of outcome.
Figure 5
Figure 5
Treated participants with attention deficit hyperactivity disorder (ADHD) compared with untreated ADHD. The percentage of the total number of outcome results is provided for each bar. The total number of studies represented in each bar is shown in parentheses. The dark green bar shows the percentage of outcome results reported as exhibiting benefit (72% of outcomes; 37 studies) in treated participants with ADHD compared with untreated ADHD. The light green bar shows the percentage of outcome results reported as exhibiting no benefit (28% of outcomes; 15 studies) in treated participants with ADHD compared with untreated ADHD. Similar to Figure 4, the sum of the numbers of studies shown under each bar does not equal the total number of studies of this type, because several studies have reported some outcomes that exhibited benefit from treatment and some that did not and so these studies are represented in both types of outcome.
Figure 6
Figure 6
Benefit and no benefit with treatment by outcome group. This graph shows benefit (dark green bars) or no benefit (light green bars) by outcome group in treated participants with attention deficit hyperactivity disorder (ADHD) versus untreated ADHD. Improvement was reported most often in studies of driving and obesity outcomes (left side), with a greater proportion of outcomes reported to exhibit no benefit following treatment compared with no treatment in studies of occupation (right side). An intermediate proportion of studies of self-esteem, social function, academic, drug use/addictive behavior, antisocial behavior, and services use outcomes reported benefit with treatment.
Figure 7
Figure 7
Treatment results by region for a subgroup of outcomes. Outcomes exhibiting benefit versus no benefit with treatment are shown for Northern America (yellow bars) versus the rest of the world (green bars). Note that Northern America includes Canada and the USA, and Rest of World, in this case, consists of countries in Europe. The response to treatment for four outcome groups was included: drug use/addictive behavior, antisocial behavior, services use, and occupation outcomes. The percentage of studies reporting benefit with treatment for these outcomes is greater for the rest of the world compared with Northern America. As in Figure 5, the sum of the numbers of studies shown under each bar does not equal the total number of studies of this type, because a single study reported an outcome that exhibited benefit from treatment and one that did not, and so this study is represented in both types of outcome.

Similar articles

See all similar articles

Cited by 101 PubMed Central articles

See all "Cited by" articles

References

    1. American Psychiatric Association. Diagnostic and Statistical Manual of Mental Disorders. 4. Arlington, VA: American Psychiatric Association; 2000. text revision.
    1. World Health Organization. International Classification of Diseases. 10. Geneva, Switzerland: WHO; 1992.
    1. Polanczyk G, de Lima MS, Horta BL, Biederman J, Rohde LA. The worldwide prevalence of ADHD: a systematic review and metaregression analysis. Am J Psychiatry. 2007;164:942–948. doi: 10.1176/appi.ajp.164.6.942. - DOI - PubMed
    1. Polanczyk G, Rohde LA. Epidemiology of attention-deficit/hyperactivity disorder across the lifespan. Curr Opin Psychiatry. 2007;20:386–392. doi: 10.1097/YCO.0b013e3281568d7a. - DOI - PubMed
    1. Fayyad J, De Graaf R, Kessler R, Alonso J, Angermeyer M, Demyttenaere K, De Girolamo G, Haro JM, Karam EG, Lara C, Lépine JP, Ormel J, Posada-Villa J, Zaslavsky AM, Jin R. Cross-national prevalence and correlates of adult attention-deficit hyperactivity disorder. Br J Psychiatry. 2007;190:402–409. doi: 10.1192/bjp.bp.106.034389. - DOI - PubMed
Feedback