In pediatric patients , the most commonly reported TEAEs were abdominal pain , decreased appetite , fatigue , nausea , somnolence , and vomiting ; time to onset of TEAEs was significantly shorter for once-daily versus twice-daily dosing for all TEAEs ( P .007 ) and for fast versus slow titration for abdominal pain , decreased appetite , and somnolence ( all P values .009 ) ; duration of TEAEs with once-daily dosing was significantly longer for decreased appetite ( P = .001 ) and nausea ( P = .041 ) ; and more common in stimulant-naive patients versus patients with prior stimulant use were abdominal pain , decreased appetite , and fatigue ( P .047 ) .