This trial was performed to test the efficacy and safety of an extended-release formulation of methylphenidate (MPH ER).
A total of 162 adults with ADHD according to DSM-IV were treated for 8 weeks with either two daily individually body weight-adjusted doses of MPH ER up to 1 mg/kg per day ( N = 84) or placebo ( N = 78). The primary efficacy outcome was the Wender-Reimherr Adult Attention Deficit Disorder Scale (WRAADDS) 8 weeks after randomization. Secondary efficacy measures were the ADHD Diagnostic Checklist (ADHD-DC), the Conners Adult Attention Deficit Disorder Scale (CAARS-S:L), the Clinical Global Impression (CGI) and the Sheehan Disability Scale (SDS).
At week 8 a significantly higher decline of the total WRAADDS score was found in the MPH ER group as compared to the placebo group ( P = 0.0003). The rates of responders were 50% in the MPH ER and 18% in the placebo group ( P < 0.0001). Furthermore, similar effects were observed for the secondary efficacy variable: ADHD-DC score ( P = 0.004), CAARS-S:L score ( P = 0.008) and the SDS score ( P = 0.017). 50% of the MPH ER group and 24.4% of the placebo group were improved “much” or “very much” according to the CGI rating ( P = 0.0001). MPH ER treatment was well tolerated. At week 2 also the mean heart rate was significantly higher in the MPH ER group as compared to the placebo group ( P = 0.01). No differences between the study groups were observed regarding mean blood pressure at any visit.