Objective: Neurocognitive evaluations are commonly integrated with clinical assessment to evaluate adult Attention Deficit Hyperactivity Disorder (ADHD). Study goal is to identify measures most strongly related to ADHD diagnosis and to determine their utility in screening processes. Participants: 230 students who were evaluated at the Vanderbilt University Psychological and Counseling Center between July 2013 and October 2015. Methods: We retrospectively examined charts, including clinical diagnosis, family history, childhood parental reported and current self-reported ADHD symptoms, psychiatric comorbidities, and continuous performance test (CPT). Result: Positive report of childhood and current ADHD symptoms, and lack of comorbid psychiatric symptoms were strongly associated with clinical diagnosis. CPT results were not associated with an ADHD diagnosis. The absence of reported childhood and current ADHD symptoms may serve as a contradictory marker for ADHD diagnosis. Conclusion: Clinical assessment of ADHD symptoms and ADHD childhood history, but not CPT, contributes to an accurate diagnosis of ADHD in college-aged adults.