Psychopharmacology (2012) 219:313–326 319 amphetamine (mg/kg) GBR12909 (mg/kg) atomoxetine (mg/kg) citalopram (mg/kg) Fig. 2 Effects of amphetamine (a), the selective DA reuptake inhibitor GBR12909 (b), the selective reuptake inhibitor atom- oxetine (c) and the selective 5-HT reuptake inhibitor citalopram (d) on 5-CSRTT performance under long ITI conditions (visual stimulus presented 7 s after trial initiation). In total, n =15 animals were included in the analysis. Asterisk indicates p <0.05 and two asterisks indicates p <0.01 compared to vehicle treatment (paired samples t- test). All data are expressed as mean±SEM present study investigated the effects of selective mono- amine reuptake inhibitors on two behavioral dimensions of impulsivity, i.e., impulsive action in the 5-CSRTT and impulsive choice in the DRT. Besides comparing three selective monoamine reuptake inhibitors and amphetamine in two separate measures of impulsivity within a single study, we aimed to address several outstanding questions with regard to monoamine neurotransmission and impulsive behavior. Thus, we have shown that the 5-HT reuptake blocker citalopram selectively reduces premature respond- ing in the 5-CSRTT but does not affect impulsive choice in the DRT. In addition, the reuptake inhibitor atom- oxetine reduced impulsive action primarily when levels of premature responding were high (i.e., under a long ITI) but