ABSTRACT
OBJECTIVES: In oder to investigate the cognitive and cortical functions of patients with conduct disorder, the present study was carried out with the neuropsychological test battery and Event-Related Potentials(ERPs:P300). METHODS: The subjects were consisted of 18 patients with conduct disorder who fulfilled DSM-IV criteria and 18 normal controls. For all subjects the neuropsychological test battery and ERPs were administered. The neuropsychological test battery consisted of attention tests, memory tests and Card Sorting Test which is used to evaluate the problem-solving and hypothesis-testing. The P300 was measured by oddball paradigm in which 1,000Hz tone was served as standard stimulus and 2,000Hz tone as target stimulus. The task of the subject was to press response-button whenever the target stimulus was presented. K-WAIS was administered in order to control the intelligence of the subjects. RESULTS: The results were as follows: 1) Among subtests of the neuropsychological test battery, only the result of Card Sorting Test showed significant difference between conduct disorder group and control group. The conduct disorder group showed significant low hit-rate compared with control group. 2) The conduct disorder group showed decreased P300 amplitude compared with control group on Fz and Cz. Among 18 patients with conduct disorder, 12 patients showed negative potentials on Fz. 3) The conduct disorder group showed prolonged P300 latency compared with control group on Fz. CONCLUSION: These results indicate that the patients with conduct disorder seem to have retarded functions of problem-solving and hypothesis-testing, and this retardation seems to be related to the frontal dysfunction.