Two @-week multicentre , double-blind , randomised , placebo-controlled studies in acute mania ( study BIA-@-@ : dose titrated by response , ESL @-@mg or @-@mg , once-daily ; study BIA-@-@ : fixed doses of @ , @ and @mg , once-daily ) were followed by a recurrence prevention study consisting of a @-week open-label period ( @mg , once-daily ) continued by a double-blind , parallel-group , fixed dose ( @ , @ and @mg , once-daily ) period for a minimum of @ months .