ADHD and adherence to antihypertensive medication treatment: a multinational cohort study

Abstract

Background: Adherence to antihypertensive medication, alongside lifestyle modifications, is fundamental to managing hypertension and reducing the risk of cardiovascular disease. Attention-deficit/hyperactivity disorder (ADHD) is a common neurodevelopmental disorder associated with a range of cardiovascular diseases, including hypertension. ADHD medication has also been associated with hypertension. However, the influence of ADHD and ADHD medication on discontinuation and adherence to antihypertensive treatments is unknown. Methods: We conducted a multinational cohort study using electronic health databases from seven countries, which included adults who initiated antihypertensive medication between 2010 and 2020. ADHD was identified by a diagnosis of ADHD or dispensation of ADHD medications. The outcomes were (1) time to the first discontinuation of antihypertensive medication and (2) poor adherence, defined as the proportion of days covered (PDC) below 80% during 1-, 2-, and 5-year follow-up periods. We used Cox proportional hazards models and logistic regression to estimate associations, adjusting for age, sex, and calendar year of antihypertensive medication initiation. We pooled results from different countries via random-effects meta-analysis. Results: We identified 12,174,321 adults who initiated antihypertensive medication during the study period, including 320,691 (2.6%) with ADHD. In the pooled analysis across all countries, ADHD was associated with an increased rate of discontinuation in 5-year follow-up of antihypertensive medication (hazard ratio [HR] 1.14; 95% CI, 1.02–1.27). In age-stratified analyses, ADHD was associated with a higher rate of antihypertensive medication discontinuation in middle-aged (HR, 1.11; 95% CI, 1.01–1.23) and older adults (HR, 1.14; 95% CI, 1.01–1.29), but not in young adults. Individuals with ADHD also had higher odds of poor adherence across 1 year after treatment initiation (odds ratio [OR] 1.45, 95% CI 1.26–1.67) to 5 years (OR 1.64, 95% CI 1.34–2.00). Among those with ADHD, use of ADHD medications was associated with lower odds of poor adherence (1 year OR 0.66, 95% CI 0.60–0.73; 5 years OR 0.58, 95% CI 0.46–0.72). Conclusions: Adults with ADHD are more likely to discontinue antihypertensive treatment and exhibit poor medication adherence. However, ADHD medication use appears to be associated with better adherence among individuals with ADHD.