What can we learn about performance validity from TOVA response profiles?

Given the functional impairments associated with Attention Deficit/Hyperactivity Disorder (AD/HD), a valid diagnosis is important. However, particularly when carried out in adulthood, the diagnostic process can be challenging and is complicated by conclusive evidence that a proportion of individuals referred for evaluation of AD/HD exaggerate or feign their symptoms. Relatively few methods, however, exist to identify such feigning. While continuous performance tests (CPTs) may provide useful information regarding performance validity, the question remains as to whether there are consistent patterns of exaggeration demonstrated by those feigning AD/HD. Thus, this study used cluster analysis to determine whether valid and reliable performance clusters would emerge based on CPT performance. Using archival data from a university-based AD/HD screening clinic, we investigated the performance of 305 adults on the Test of Variables of Attention (TOVA). Three profiles emerged, including one cluster who demonstrated exceptionally low performance on the TOVA, exceptionally high reports of AD/HD symptomology, and higher rates of failure on symptom and performance validity tests. The implication from our analysis is that this group most likely represents individuals who were exaggerating or magnifying their difficulties. The results reaffirm previous research showing that performance profiles on a continuous performance test can be used as an indicator of credible performance.