OBJECTIVES: To compare deviation rates from the labeled average daily consumption (DACON) in patients with ADHD initiated on lisdexamfetamine dimesylate (LDX) versus other once-daily FDA-approved stimulant medications. METHODS: Patients with ADHD initiated on a stimulant medication on or after February 23, 2007 were selected from a large US claims database. Based on age and previous treatment, patients were classified into treatment-naïve or previously-treated children/adolescents (6-17 years old), and adults (≥18 years old), respectively. Furthermore, based on the initiated medication, patients were classified into 4 cohorts: LDX, methylphenidate HCl (OROS MPH), other methylphenidate/dexmethylphenidate HCl long acting (MPH LA), and amphetamine long acting (AMPH LA). DACON was defined as the quantity of units supplied divided by the number of days of supply in the 12-month study period. The proportion of patients who deviated from the labeled DACON (ie, DACON >1 pill/day) and the likelihood of deviation from the labeled DACON were compared across cohorts using chi-square tests and multiple logistic regression models, respectively. RESULTS: Across all subgroups, the proportion of patients who deviated from the labeled DACON was significantly higher in each treatment cohort (range: 7.4%-29.4%) versus the LDX cohort (range: 2.9%-9.9%) (all p<0.001). After adjustments, uniformly across all subgroups, patients in each treatment cohort were significantly more likely to deviate from the labeled DACON versus LDX-treated patients. In children/adolescent groups, odds ratios ranged from 2.6 to 3.7 and 2.9 to 4.1 in the previously-treated and the treatment-naïve cohorts, respectively (all p<0.001). In adult groups, odds ratios ranged from 2.1 to 4.0 and 2.1 to 4.1 in the previously-treated and the treatment-naïve cohorts, respectively (all p<0.001).   CONCLUSIONS: Findings suggest that LDX-treated patients were more likely to adhere to the dosing regimen recommended in FDA labels and were less likely to have a DACON >1 compared with patients treated with other once-daily stimulant ADHD medications.