Objective: Investigate the association between diagnosis and outcomes in adults with symptoms of ADHD. Method: The Validate Attitudes and Lifestyle Issues in Depression, ADHD and Troubles with Eating (VALIDATE) study collected sociodemographic and clinical characteristics data, and responses from validated questionnaires on health-related quality of life (HRQoL), work productivity, functioning, and self-esteem. ADHD-diagnosed respondents (n = 444) were matched with respondents with symptomatic ADHD (n = 1,055) within the same sex-by-age group using propensity score matching. Effects of ADHD diagnosis on each outcome were adjusted for covariates that remained imbalanced after matching, using generalized mixed models. Results: After matching, symptomatic respondents (n = 867) had worse outcomes than ADHD-diagnosed respondents (n = 436), as measured by the Work Productivity and Activity Impairment: General Health questionnaire and Sheehan Disability Scale (p < .001). ADHD-diagnosed respondents had better mean EuroQol five-dimensional five-level (EQ-5D-5L) scores and Rosenberg Self-Esteem Scale scores than symptomatic respondents (p < .001). Conclusion: ADHD-diagnosed individuals are more likely to experience better functional performance, work-related productivity, HRQoL, and self-esteem than individuals with symptomatic ADHD.
Keywords: adult ADHD; diagnosis; functional impairment; health-related quality of life.