Following evaluation of the maximum tolerated dose , SERT occupancy was determined by applying -LSB- ( @ ) C -RSB- DASB positron emission tomography ( PET ) after single-dose BMS-@ ( @ or @ mg ; n = @ each ) and DAT occupancy by applying -LSB- ( @ ) C -RSB- PE@I PET after single-dose BMS-@ ( @ mg ; n = @ ) .