Susceptibility of functional impairment ratings to noncredible reporting in postsecondary students undergoing screening for ADHD.

Objective: Clinical evaluation for attention-deficit/hyperactivity disorder (ADHD) not only requires assessment of symptoms, but also consideration of the degree to which symptoms lead to impairment within various functional domains. However, ADHD evaluations in adulthood often rely on self-reported functional impairment, which might be vulnerable to malingering/noncredible responding. The present study utilized a clinical sample/known groups design to examine the relationship of noncredible presentation to functional impairment ratings by analyzing differential associations with both symptom and performance validity tests (SVTs and PVTs). Method: Participants were 168 postsecondary students who completed psychoeducational assessments for ADHD to determine their eligibility for academic accommodations and/or medications. Impairment ratings on the Weiss Functional Impairment Rating Scale (WFIRS) of 71 students who presented in a noncredible fashion were compared to 72 students who appeared to present credibly (controls) and 25 students diagnosed with ADHD who appeared to present credibly (clinical controls). Results: Relative to both control groups, individuals who presented noncredibly reported higher levels of disability on most functional domains and a higher percentage provided responses that fell in the impaired range on all functional domains of the WFIRS. Conclusions: Findings provide additional evidence that ADHD-related functional impairment ratings are susceptible to noncredible presentation and highlight the need for assessors to include both SVTs and PVTs in ADHD evaluations.