Functional Impairments Associated With ADHD in Adulthood and the Impact of Pharmacological Treatment

Abstract

Objective: Among untreated adults, functional impairments associated with ADHD are widespread and cumulative, and can include social, educational, and professional impairments, increased risk of accidents and mortality, and reduced quality of life. Here, we review the most prominent functional impairments in adults with ADHD and summarize evidence describing the potential role of medication in improving outcomes.

Method: Articles related to the search terms "ADHD," "adult," and functional impairments were identified through Google Scholar and PubMed and selected for inclusion based on four criteria: strength of evidence, relevance to current challenges in adult ADHD, impact on the field, and recency of the results.

Results: We identified 179 papers to support the conclusions on the relationship between ADHD and functional impairments, and the impact of pharmacological therapy on functional impairments.

Conclusion: This narrative review provides evidence that pharmacological treatment can be effective in minimizing not only the symptoms of ADHD, but its functional consequences as well.

Keywords: adult ADHD; attention-deficit/hyperactivity disorder; functional impairment; nonstimulant; stimulant.

Figure 1.

Feelings evoked while watching behaviors characteristic of ADHD. Watching a social interaction in which behaviors characteristic of ADHD were evident (ADHD Condition) invoked more hostility and prompted more rejecting responses than watching an interaction in which no psychopathological behaviors were displayed (Control Condition). Cohen’s d effect sizes were medium and large. Means ± standard error. *p = .012, **p < .01. (Data from Paulson et al., 2005.)

Figure 2.

Parenting variables for mothers with low and high ADHD symptomology. (a) Mothers with greater ADHD symptomology perceived themselves as less effective and felt greater dissatisfaction with their parenting. (b) Mothers with greater ADHD symptomology were more likely to be lax with discipline (e.g., giving in, allowing rules to go unenforced), and more likely to be overreactive (e.g., becoming angry or irritable). Cohen’s d effect sizes ranged from medium to large. *p < .05. (Data from Banks et al., 2008.)

Figure 3.

Cumulative risk of injury in adults with ADHD with and without medication. (a) The cumulative risk of injury for adults with ADHD (solid line) is significantly greater than for those without (dotted line). (b) Among adults with ADHD, the cumulative risk of injury is significantly greater for those never having received medication for their ADHD (dotted line) than for those who did (solid line). Data are from a Kaplan-Meier analysis and log-rank test. (Picture reprinted with permission from Chien et al., 2017.)

Figure 4.

Negative driving outcomes. (a) Adults with ADHD had significantly more negative driving outcomes than those without, based on self-report history and official DMV records (means ± standard error). (b) A greater percentage of adults with ADHD met criteria for various negative driving outcomes than the control group, based on self-report history. ** p < .01, *** p ≤ .001. Note. DMV = official Department of Motor Vehicles records; SR = self-report history. (Data from Barkley et al., 2002.)

Figure 5.

Sleep problems in adults with persistent, remitted, or late-onset ADHD. Sleep problems were greatest among participants whose childhood ADHD persisted into adulthood and those with adult-onset ADHD, versus those whose childhood ADHD remitted in adulthood or those never diagnosed with ADHD at all. Asterisks directly above the bars are for comparisons with the “no ADHD” group and asterisks above the brackets are for comparisons between the groups indicated. ~ p < .10, *** p < .001. Note. ns = not significant. (Reprinted with permission from Gregory et al., 2017.)

Figure 6.

FDA-approved treatments for ADHD. FDA-approved treatments for ADHD include stimulants and nonstimulants. Stimulants include amphetamine- or methylphenidate-based products, of which there are a variety of formulations available. Nonstimulants include atomoxetine, guanfacine extended-release (guanfacine XR), clonidine extended-release (clonidine XR), and viloxazine extended-release (viloxazine ER). Guanfacine XR and clonidine XR have not been approved to treat ADHD in adults; a randomized, placebo-controlled phase 3 trial of viloxazine ER in adults with ADHD has recently been completed (NCT04016779), with an open-label extension underway (Nasser et al., 2022). Note. FDA = Food and Drug Administration.

Figure 7.

Improvement on social and relationship items after stimulant and nonstimulant treatment. Treatment with instant-release methylphenidate (MPH) and atomoxetine (ATX) significantly improved social and relationship items on the Adult ADHD Quality of Life Scale (AAQoL) and Weiss Functional Impairment Rating Scale–Self-Report (WFIRS) in ADHD within 4 to 5 weeks of treatment. Cohen’s d effect sizes (white boxes within bars) were medium to large. Means ± standard error. * p < .05, ** p < .01, *** p < .001, relative to baseline. (Data from Ni et al., 2017.)

Figure 8.

Associations between medication usage and criminal conviction among men with ADHD. Using data from the Swedish National Patient Register, both stimulant and nonstimulant ADHD medications significantly reduced the likelihood of any criminal conviction among men with ADHD, whereas selective serotonin reuptake inhibitor (SSRI) medication did not (a). The use of ADHD medication was associated with significantly decreased rates of crime as assessed by multiple outcomes (b). Hazard ratio (below each red circle) ± 95% confidence intervals. Confidence intervals which include 1.0 are not significantly different from the comparison (here, relative to no medication). (Data from Lichtenstein et al., 2012.).