Diagnosis of adult attention-deficit/hyperactivity disorder (ADHD) adults is difficult, as neither symptom report nor neuropsychological findings are specific to ADHD. Few studies address the possibility that noncredible performance influences both symptom report and neuropsychological findings. The present study utilized archival data from young adults referred for concerns about ADHD, 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 but no ADHD. Results showed a 31% failure rate on the WMT. Those who failed the WMT showed clinical levels of self-reported ADHD symptoms and impaired neuropsychological performance. Neither self-report measures nor neuropsychological tests could distinguish ADHD from psychological controls, with the exception of self-reported current hyperactive/impulsive symptoms and Stroop interference. Results underscore the effect of noncredible performance on both self-report and cognitive measures in ADHD.

Results support the clinical validity of this brief computerized screening battery when used in established dementias, but not to differentiate between various dementias, and suggest that the select CogState battery's effectiveness in identifying MCI from controls was not as strong as identifying specific dementias.

In established dementia, administration of the CogState tasks appears sensitive to cognitive impairment in dementia. Repeat administration also provided acceptable stability and test-retest reliability with minimal practice effects at short test-retest intervals despite intervening cognitive challenges.

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The Iowa gambling task (IGT) was designed to assess clinically relevant decision-making impairment, yet some studies find high rates of failure in otherwise healthy control groups. The current study examined variables potentially related to IGT failure, including negative affect, intellect, personality, and executive functioning, in a well-screened sample of healthy young adults. In addition, cerebral oxygenation (near-infrared spectroscopy) was assessed. Results indicated that those who failed the IGT had lower estimated intellect, made more commission errors on the 2-back task, and showed less bilateral dorsolateral prefrontal cortex oxygenation, relative to those who passed. Overall findings are consistent with prior literature suggesting that frontal lobe functioning is related to successful IGT performance and that executive functioning and working memory skills are important components of IGT performance, even in those without clinical disorders or evidence of "real world" dysfunction.