Attention deficit/hyperactivity disorder diagnosis in adulthood: Prevalence and predictive utility of...

This cross-sectional study investigated the prevalence of adult Attention Deficit/Hyperactivity Disorder (ADHD) evaluations in an outpatient neuropsychology clinic and the sensitivity and specificity of neuropsychological assessments in differentiating ADHD with comorbid psychiatric conditions from psychiatric-related cognitive deficits.

Logistic regression analyses were run on neuropsychological testing results extracted from medical records to evaluate each test's ability to predict ADHD diagnosis. Receiver Operating Characteristic curves were plotted, and an Area Under the Curve (AUC) >0.7 was considered acceptable.

Sixty-seven of 252 reviewed charts were included (n = 30 with ADHD, n = 37 without ADHD). Overall, 54% of individuals presenting to the clinic were referred for ADHD, and 58% of those diagnosed with ADHD had a comorbid psychiatric disorder. No cognitive testing was predictive of ADHD diagnosis (AUC range: 0.503-0.636). The Generalized Anxiety Disorder-7 was the strongest predictive scale of ADHD (AUC = 0.800; χ2(28) = 8.216, p = .004, Nagelkerke R2 = 0.333). Adults who endorsed higher levels of anxiety were 28% more likely to be diagnosed with ADHD (OR = 1.28, 95%CI [0.05, 0.45]). Subtests of ADHD scales performed worse, but still within the adequate range (AUC range: 0.703-0.751). Sample demographics were notable for over-representation of women (n = 46, 69%), and they skewed White (n = 43, 64%) and highly educated (M years of education = 15.79, SD = 1.94), which may limit generalizability.

Cognitive testing profiles and screeners of current inattention and hyperactivity were indiscriminate between individuals with ADHD and comorbid psychiatric conditions versus psychiatric conditions alone. Current anxiety was the strongest predictor of adult ADHD diagnosis.