A comparison between adults with conduct disorder and normal controls on acontinuous performance test: Differences in impulsive response characteristics

Continuous Performance Test (CPT) responding was compared between 15 adults with a history (childhood/adolescent) of Conduct Disorder (CD) and 15 norm al controls. Of particular interest was whether response latencies and comm ission errors, which have been suggested to be measures of impulsivity, wou ld differ between the groups. The CPT procedure used included two condition s: Immediate Memory Task and Delayed Memory Task (IMT/DMT; Dougherty et al. , 1998). Both the IMT (0.5-s delay) and DMT (3.5-s delay with distracter st imuli at 0.5-s intervals) required the subject to respond if a briefly disp layed number was identical to the one presented before it. Stimuli included target (identical match), catch (four of five digits matched), and novel ( no match). Participants completed six 22-min testing sessions scheduled acr oss a single day. The most significant findings were that the CD group (com pared to the control group) had (a) elevated commission errors (responses t o catch stimuli); (b) lower stimulus discriminability (between target and c atch stimuli); and (c) shorter response latencies. These results are consis tent with the few previous studies indicating that these parameters are rel ated to impulsive behaviors.