Pre-existing cardiovascular conditions and pharmacological treatment of adult ADHD
Stimulants and atomoxetine should generally not be used or used only with caution in adults with pre-existing cardiovascular conditions. The extent to which pre-existing cardiovascular conditions influence initiation of these ADHD medications in adults is not known. We performed a retrospective cohort study of privately insured adults with new ADHD treatment episodes. Pre-existing cardiovascular conditions were assessed by the presence of ICD-9-CM codes for congenital abnormalities, atherosclerosis, cardiac disease, and cerebrovascular disease in the 12 months before the index ADHD diagnosis. The primary outcome was new initiation of a stimulant or atomoxetine in the 3 months after the index date. Multivariate logistic regression was used to predict the likelihood of treatment initiation with stimulants or atomoxetine based on pre-existing cardiovascular conditions, patient demographic characteristics, clinical mental disorder comorbidities, other psychotropic drug use, and provider type. Of 8752 patients with a new ADHD treatment episode, 917 (10.5%) had evidence of >or=1 pre-existing cardiovascular condition. Stimulants were started by 40.8% of patients with and 53.0% of patients without pre-existing cardiovascular conditions (Adjusted Odds Ratio, AOR 0.71; 95%CI 0.61-0.82). Pre-existing cardiovascular conditions reduced the likelihood of initiating stimulant treatment in younger but not in older patients (p-value for age x cardiovascular condition interaction = 0.0002). Initiation of atomoxetine treatment was not affected by pre-existing cardiovascular conditions (AOR 1.19, 95%CI 0.94-1.50). Pre-existing cardiovascular conditions reduce the likelihood of stimulant therapy but not atomoxetine treatment in adult ADHD patients. However, many adult ADHD patients with pre-existing cardiovascular conditions initiate stimulant therapy.