Adult Attention Deficit-Hyperactivity Disorder is associated with Lewy Body Disease and Cognitive Impairment: A prospective cohort Study With 15-year Follow-Up.

OBJECTIVES: Past reports have suggested that attention-deficit/hyperactivity disorder (ADHD) may be a risk factor for Lewy body disease (LBD). To confirm this relationship, we conducted the present study.

DESIGN: A prospective observational cohort study with a follow-up to 15 years.

SETTING: The subjects were recruited from cognitive neurology clinics, where they attended for a cognitive complaint or health check-up.

PARTICIPANTS: Two groups of subjects: ADHD adults and healthy subjects.

MEASUREMENTS: The risk of dementia and LBD was estimated with Kaplan-Meier analysis comparing for the presence or absence of ADHD with the log-rank test. Predictors of conversion were assessed through separate univariate and multivariate Cox regression analyses, adjusting for several variables.

RESULTS: The baseline sample consisted of 161 subjects with ADHD and 109 without ADHD. At the end of the follow-up, 31 subjects developed dementia, 27 cases in the ADHD group and 4 in comparison group. Dementia with Lewy bodies (DLB) was the most frequent type (N:20) of which 19 corresponded to the ADHD group. The incidence of non-amnestic-MCI in the ADHD group was higher representing 67.1 % of these subjects (N:108), and 17.4% (N:19) of healthy cases. The hazard ratios for dementia and LBD in the multivariate adjusted model were 3.33 (95% CI 1.0915 to 10.1699) and 54.54 (95% CI 7.4849 to 397.5028), respectively in the ADHD group.

CONCLUSIONS: This study showed that adult ADHD is independently associated with an increased risk of LBD, dementia, and na-MCI. Future studies should clarify this relationship to develop preventive measures for these patients.