Previously , in a 40-week , randomised , double-blind , placebo-controlled core study comprising three phases ( 9-week dose confirmation , 5-week open-label dose optimisation and 6-month maintenance of effect ) in adults with attention-deficit/hyperactivity disorder ( ADHD ) , methylphenidate modified-release long-acting formulation ( MPH-LA ) at 40-80 mg/day controlled ADHD symptoms as well as decreased functional impairment with a good tolerability profile ( NCT01259492 ) .