ERROR PATTERNS ON THE CONTINUOUS PERFORMANCE-TEST IN NONMEDICATED ANDMEDICATED SAMPLES OF CHILDREN WITH AND WITHOUT ADHD - A METAANALYTIC REVIEW

We systematically reviewed the patterns of Continuous Performance Test (CPT) errors of omission and commission exhibited by normal children and children with Attention Deficit and Hyperactivity Disorder (ADHD) under no drug, placebo and methylphenidate drug conditions. Findings f rom 26 studies were submitted to a meta-analytic procedure. In contras t to the contradictory findings of individual reports, our results rev ealed that children with ADHD made significantly more errors of omissi on and commission than normal children. As well, in children with ADHD and treated with methylphenidate, statistically significant reduction s in the rate of both error types were noted. The effects of methylphe nidate on the percentage of hits (i.e. 1 - omissions) were greater in experiments using shorter stimulus duration, smaller number of trials and higher probability of a target. Using Signal Detection Theory (SDT ) parameters, we found that children with ADHD were less sensitive to the difference between targets and non-targets than their normal count erparts, while showing a comparable response bias. Similarly, the effe cts of methylphenidate were restricted to improving the sensitivity, w hile not affecting response bias, in both normal children and those wi th ADHD. Copyright (C) 1996 Association for Child Psychology and Psych iatry.