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