The relationship of noncredible performance to continuous performance test scores in adults referred for attention-deficit/hyperactivity disorder evaluation.

Diagnosis of Attention-Deficit/Hyperactivity Disorder (ADHD) in adults is complicated by the fact that neither symptom report nor neuropsychological findings are specific to the diagnosis. Few studies have addressed the possibility that noncredible performance influences the effectiveness of neuropsychological test findings in ADHD assessment. The present study utilized archival data on Conner's Continuous Performance Test (CPT) scores from young adults referred for concerns about ADHD at two different universities, who were divided into three groups: (1) those who failed a measure of noncredible performance (the Word Memory Test; WMT), (2) those who met diagnostic criteria for ADHD, and (3) controls with psychological symptoms who did not meet the diagnostic criteria for ADHD. More individuals who failed the WMT were also clinically impaired on the CPT than individuals diagnosed with ADHD and individuals with psychological symptoms, who could not be distinguished from each other. Results demonstrate the importance of assessing for noncredible performance before interpreting neuropsychological test scores in ADHD assessment. Results also emphasize the importance of considering other disorders that can impact CPT performance prior to interpreting CPT impairment as indicative of ADHD.