CLINICAL UTILITY OF NOVEL CPT USING ANIMAL IMAGES

Objectives: Several types of the continuous performance test (CPT) have been widely used in diagnosing ADHD and monitoring the effect of stimulant medications. However, taking long time and using monotonous stimuli such as letters or numbers for the test sometimes make it difficult to finish especially for younger subjects with ADHD. We have applied a novel type of visual CPT, MOGRAZ®, which shows attractive animal images mimicking Japanese traditional game, for clinical evaluation of ADHD symptoms. In this study, we compared the performance of the test in healthy subjects and children with ADHD, on and off effect of methylphenidate in some patients.

Methods: We recruited 25 healthy children and 21 children with combined type of ADHD, who had been diagnosed based on DSM-IV, between 6 and 14 years old. In the 10 minutes task, 400 images of a mole with/without glasses were randomly presented on the certain quartered area of the 17-inch CRT. Subjects were required to press key button when target stimuli (a mole with glasses) appeared with a rate of 50%. Twelve ADHD children performed the task before and 1 hour after taking 5mg of methylphenidate.

Results: Variability of reaction time as well as commission and omission errors increased significantly in ADHD group (p<0.05). Methylphenidate reduced both error rates and variability in 8 out of 12 medicated subjects.

Conclusion: This task may be useful for clinical evaluation of attention and impulsivity in ADHD subjects, especially in younger ones. Moreover, the task could detect some of the stimulant-sensitive performance changes.